Over the past two decades, three groundbreaking spacecraft missions have returned samples from asteroids, enabling significant advancements in the study of small planetary bodies. JAXA’s Hayabusa mission brought back surface fragments from the S-type asteroid (25143) Itokawa on 13 June 2010. A decade later, on 6 December 2020, JAXA’s Hayabusa2 returned 5.4 grams of material from the C-type asteroid (162173) Ryugu. Most recently, on 24 September 2023, NASA’s OSIRIS-REx mission delivered 121.6 grams from the B-type asteroid (101955) Bennu. This multidisciplinary special session invites cutting-edge presentations on the analysis of these valuable samples from Itokawa, Ryugu, and Bennu, shedding light on the formation and evolution of the earliest planetary materials in the solar system. Topics will range from geochemical and mineralogical insights gained from sample analysis to the integration of remote sensing data with ground-based studies, providing a comprehensive understanding of each asteroid's geological history. Additionally, the session will highlight the latest technical advancements in sample analysis techniques, data management, and archiving, and the curation of asteroidal samples.

This session seeks to celebrate the life and scientific achievements of Grenville Turner FRS, a leading figure in the field of isotope geochemistry and cosmochemisty. Grenville is best known for developing the ⁴⁰Ar-³⁹Ar dating method, which has played a key role in decoding the history of Earth and our solar system. Now used in virtually all aspects of Earth and planetary science, it has provided key insights into fundamental questions such as the origin and age of the Moon, the timing of impacts and mass extinctions and the evolution of flora and fauna, including the emergence of our own species. Through the development of ⁴⁰Ar-³⁹Ar dating Grenville was able to provide insights into the thermal histories of rocks and meteorites, trace the movement of terrestrial and extra-terrestrial crustal fluids and reconstruct the evolution of planetary atmospheres. Grenville pioneered new and innovative analytical approaches including the development of step heating, lasers and in-vacuo crushing techniques for extracting noble gases from minerals, resonance ionisation analysis of Xe isotopes which led to the demonstration that ²⁴⁴Pu was present in ancient terrestrial zircons. Original contributions in geochronology, geochemistry and cosmochemistry, as well as new developments in analytical techniques, are welcome for this session with a strong focus on understanding the prehistory, formation and evolution of our planet and the solar system. Continuing Grenville's legacy of fostering and supporting young scientists, we strongly encourage contributions from early career researchers and under-represented groups with the aim of hosting a session promoting diversity and inclusion.

How did the planets and asteroids in our solar system form and evolve? These questions are crucial for unraveling the origins of the solar system and how it became what it is today. This session focuses on the formation mechanisms and timescales of the crusts, mantles, and cores of asteroids and inner planets, key processes that shaped their internal structures and overall evolution. This session discusses analytical and experimental studies of extraterrestrial materials and theoretical modeling of planets and asteroids to better understand the formation and evolution of rocky bodies. This session invites abstracts on chemical, isotopic, and modeling insights that shed light on how planets/asteroids accreted, planetary interiors differentiated, and the dynamic processes that have shaped their evolution over time.

Accretionary processes during the first couple or a few hundred million years set the initial conditions for the long-term evolution of planets in the Solar System. To understand this early history, we increasingly rely on integrated models of planetary accretion that combine cosmo/geochemical observations, high-pressure experiments, and atomistic as well as astrophysical modeling across a wide range of temporal and spatial scales. In this session, we invite interdisciplinary contributions on any physical or chemical aspects of planetary accretion and evolution, using observational, experimental, and/or theoretical methods, including, but not limited to, cosmochemistry, geochemistry, astrophysics, mineral physics, experimental petrology, and planetary sciences.

Primitive materials such as primitive meteorites, interplanetary dust particles (IDPs) and micrometeorites offer a rare glimpse into the earliest stages of the Solar System's formation and evolution. Such materials represent the most abundant fraction of the flux of extraterrestrial materials to the Earth and constitute our main source of cometary and primitive asteroid samples available for laboratory studies. They thus offer a unique window into the journey of primordial gas and dust from stellar ignition to the formation of the first solids, the movement of materials between the inner and outer regions of the Solar System, the development of planetary bodies and the later addition of volatile and organic compounds on inner planets.

This session will cover topics including the ongoing flux of these primitive extraterrestrial materials such IDPs, micrometeorites, and primitive meteorites to Earth, their mineralogical and geochemical makeup, and their role in transporting elements to early Earth. We will examine their pristine components and delve into their role in delivering organic compounds to early Earth and facilitating elemental exchange in the upper atmosphere, providing insights into the paleo-atmosphere and its evolution. We welcome contributions on the mineralogical, geochemical, and isotopic compositions of these extraterrestrial materials, including theoretical and experimental studies, as well as advancements in modeling of dust delivery to the Earth.

Throughout the Solar System, planetary bodies witness complex formation and evolution histories. The combination of different analytical approaches and datasets allows us to disentangle the complex signatures of planetary interior and surface processes. Analytical techniques enable precise determinations of the ages and compositions of samples. Remote sensing data can provide vital insights to volcanic and impact cratering histories, crust and atmosphere composition and the broader geologic context of rock lithologies. Impact craters and impactite lithologies inform us about the bombardment histories of different planetary surfaces. In this session, we invite contributions discussing the petrologic, geochemical and isotopic analysis of samples from differentiated planetary bodies such as the Moon, Mars, Vesta, and beyond, as well as complimentary numerical, experimental and remote sensing studies that bring a better understanding of planet and planetesimal origin and evolution.

Fluids and volatile-rich melts play a pivotal role in driving dynamic processes within Earth's interior, for instance in subduction zones, the upper mantle and the lithosphere. This session will explore the geochemical, petrological, and geophysical impacts of deep fluids — such as dehydration embrittlement, metamorphism, metasomatism, metal mobilization, redox changes — on mantle and crustal evolution. A key focus will be on the sources, compositions, and transport mechanisms of deep fluids, their role in mineralogical transformations, and their influence on magmatism. We also invite contributions on volatile-rich melts, such as carbonatites and kimberlites, which emerge from the mantle and transport, alongside fluids, large amounts of incompatible elements between the mantle and the crust.

By integrating field observations, experimental studies, and numerical models, this session will bring together a multidisciplinary approach to understand the far-reaching consequences of deep fluid and melt processes for mantle dynamic, element cycle, seismicity, volcanic activity and ore deposit formation. We invite contributions from geochemistry, petrology, geodynamics, and mineral physics to foster discussions on the role of fluids and volatile-rich melts in shaping Earth's interior.

Chalcophile and siderophile elements have long been used as key tracers for such processes as planetary formation and differentiation, mantle melting and fractionation, and crust formation and evolution. These geochemical messengers also have a strong economic importance as critical and strategic metals whose exploration, production and recycling increase every year. Some of these heavy elements are highly toxic for the biota and pose a growing threat for the environment through mining and ore processing.

This session invites geochemical, mineralogical, and petrological studies that address the behaviour in the planetary interiors of chalcophile and siderophile elements, including, but not limited to, platinum group elements, noble metals Au and Ag, the Fe-Ni-Co, Zn-Cd and Cu-Mo-W families, as well as volatile metals and metalloids such as As, Sb, Se, Hg or Tl. We are welcoming entries on analytical, experimental, and modelling advances in the field, including machine learning and new interdisciplinary instruments, such as synchrotron radiation or atom probe in relation to geological applications. This session also invites studies on global abundances and cycles, isotopic compositions, and chemical and redox speciation and partitioning of chalcophile and siderophile elements in nature and laboratory across the wide range of conditions and scales, from the mantles and cores of extraterrestrial bodies to the Earth’s surface.

The two large low velocity provinces (LLVPs) in the lower mantle, beneath Africa and Pacific originating from the core mantle boundary as detected seismically, play a critical role in the evolution of our planet since they not only dominate the interplate volcanisms and therefore affect the habitability of the Earth’s surface, but also act as the counter flow of slab subduction and thus maintain the material transportation between shallow regions and the deep interior. This session will explore the properties and dynamics of LLVPs through of geophysical observations, geochemical analysis, mineral physics investigations via high pressure and high temperature experiments and first principle calculations, as well as geodynamical simulations, combined with machine learning techniques. The key focuses include the compositional, thermal and rheological properties of LLVPs, their formation and dynamic evolution, the core-mantle interactions, the geochemical characteristics of large igneous provinces and oceanic island basalts originated from the LLVPs, and the impacts of LLVPs on mantle convections and surface environments. We invite contributions from geophysics, geochemistry, high pressure and high temperature experiments, first principle calculations, and geodynamical simulations to foster discussions on the origin, properties, dynamic evolutions, and impacts of LLVPs.

The knowledge of the oxidation state and partitioning behaviour of heterovalent elements (e.g., Fe, V, Co, Cr, C, S, etc.) in minerals, melts and fluids is fundamental to track redox processes occurring in the terrestrial planets through space and time. Some of these processes include, but are not limited to, formation of the cores and atmospheres of these planets, evolution of Earth’s mantle redox state through time, the partial melting of mantle rocks (e.g., promoted by the circulation of oxidized volatile species such as CO₂ and H₂O), diamond formation, abiotic dehydrogenation and methanogenesis in metamorphic environments. Volatile release through volcanic gases and their subsequent exchange with the solid Earth and the exosphere has implications for the composition of the atmosphere of the Earth, as well as habitability of rocky planets more generally.
We invite contributions on mineralogical, petrological and geochemical studies aimed to constrain redox-driven processes both at the surfaces and at depth of terrestrial planets.

Diamond is an important mineral for understanding composition and evolution of the deep mantle. This mineral’s unique properties provide insights into the Earth's interior up to 2500 km deep. Diamond is among the oldest known minerals, and with its exceptional mechanical and chemical stability, diamond records information about the mantle, and transport this data to the surface, where it remains preserved despite prolonged exposure to weathering and alteration. During crystallization, diamonds encapsulate minerals and fluids, which remain isolated from the evolving mantle. The external surfaces of diamond crystals reflect Phanerozoic processes involved in the emplacement of diamonds within volcanic rocks. We invite contributions on the study of mineral and fluid inclusions within diamonds, their stable and radiogenic isotopes, as well as the implications of these data for understanding the evolution, thermal state, age, and processes within the continental lithospheric and asthenospheric mantle. Contributions on the crystallography and spectroscopy of diamonds and their inclusions are welcome. The session will also feature experimental research related to the genesis and dissolution of diamonds, and chemical and spectroscopic methods of diamond studies.

The isotopic compositions of non-traditional elements (e.g. Si, Ca, Ti, Fe, Ni, Zn, Mo, Sn) are an exciting addition to the geochemist’s toolbox and have found a rapidly increasing use in the study of a wide range of high-temperature processes. As such, non-traditional stable isotopes have provided valuable new insights into a range of processes including planetary differentiation and volatile budgets, mantle sources of oceanic basalts, mass transfer in subduction zones, crust formation through time, and mineral-melt reactions.

Over the past years, experimental techniques and ab-initio calculations have become crucial to understand with precision the vast array of processes that operate within Earth’s interior. Unlocking the full potential of non-traditional stable isotope data necessitates the robust quantification of the degree of fractionation between the relevant phases of interest (e.g. melts, minerals, fluids, vapours). Isotope fractionation factors from both kinetic and equilibrium processes derived from experimental studies and ab-initio calculations provide the framework with which to effectively rationalise and model natural isotope data. For instance, further experimental constraints on kinetically induced isotope fractionation of volatile elements could help tackle the question of volatile loss during planetary formation and giant impacts. This session provides a podium for the exciting vistas offered through experimental and theoretical calibrations of isotope fractionation. We welcome a wide range of contributions that aim to further our understanding of stable isotope fractionation at high-temperature using experimental techniques (e.g. gas-mixing furnace, piston cylinder, multi-anvil studies) or first-principles calculations.

Peridotites, pyroxenites and eclogites, which sample Earth’s lithospheric mantle, have provided a wealth of information on the petrological and geochemical processes that formed Earth’s interior and contributed to its continuous evolution. Episodic depletion events and percolation of melts and fluids have left their traces by changing textures and compositions of main constituent minerals and newly introduced phases that can provide valuable clues in addition to what can be learned from whole-rock major, trace elements or isotopes in bulk mantle samples. Furthermore, instrumental analytical developments in the last decades have opened new perspectives allowing us to explore the chemical and isotopic composition of micrometer- and even nanometer-sized areas revealing their power in interpreting the whole-rock signatures.

We invite researchers from diverse backgrounds (petrology, experimental petrology, geochemistry, geophysics, geodynamics) to contribute to this broadly-themed session on topics that include but are not limited to (1) the record of melting events, melt-rock and fluid-rock reactions in the sub-continental lithospheric mantle and oceanic mantle (2) detailed isotopic (stable and radiogenic) studies and dating of mantle processes and (3) studies of accessory and minor phases in peridotitic, pyroxenitic and eclogitic samples.

The Earth's interior—including the core, mantle, and lithosphere—plays a fundamental role in the functioning of the Earth system, directly influencing the evolution of surface habitability. In recent decades, low-temperature geochemists studying Earth's surface history and solid Earth geochemists, geophysicists, and petrologists examining the interior have tended to work in relative isolation. This section aims to bring together experts from different fields to understand the connection between deep and surface processes and deep mechanisms driving the evolution of Earth's habitability throughout geological history. We encourage submissions on topics such as the distribution and properties of volatiles within Earth's interior, the cycling and dynamics of carbon, hydrogen, and oxygen in the deep Earth, and the chemical reaction mechanisms occurring in the deep Earth and their effects on the surface. We also welcome low-temperature geochemical studies focused on understanding the evolution of Earth's surface habitability. Our goal is to unravel the mysteries of the deep Earth engine and promote significant theoretical innovations in Earth system science.

Interfacial geochemistry plays a crucial role in deep geochemical and geophysical processes, influencing exchange and fluxes of material and energy between compartments with different properties. At interfaces between solids, fluids (e.g., water or hydrocarbons) and gases, reactions drive transformations that influence  the cycling of key elements and molecules. This session focuses on the role of interfacial processes in shaping the chemistry and dynamics of deep regions from the lower part of the upper crust to the upper mental, and how they impact rock properties.

We invite contributions that integrate experimental, theoretical, and observational studies to explore the interactions between different minerals, fluids and organic species at high-pressure and high-temperature interfaces in deep geosystems. This includes the role of microdroplets, reactive mineral-fluid interfaces in material transport and key geochemical transformation in all compartments that are not accessible by deep boreholes, including subduction zones and hydrothermal systems; all of them control the deep carbon cycle. Experimental and theoretical advances in studying interfacial reactions are thus welcome in order to study how interfacial processes might influence deep dynamics and element cycling. This session also encourages interdisciplinary contributions that integrate geochemistry, petrology, mineral physics, and geophysics to enhance our understanding of the complex interfacial dynamics occurring.

By advancing our understanding of interfacial processes at high P, T conditions, this session aims to uncover the mechanisms that link deep geochemistry with surface processes, contributing to a holistic view of planetary evolution.

A thorough understanding of the underlying mechanisms and quantification of diffusion-controlled processes as a function of key thermodynamic parameters (e.g., composition, temperature, pressure, fugacities of volatile species, etc) is fundamental for Earth and planetary sciences. Indeed, ionic diffusion is a ubiquitous process which takes place in both crystalline and amorphous matter, at all spatial scales and within all envelopes of Earth and planetary bodies. Thus, it is not surprising that it finds application as a tool for determining timescales of terrestrial and planetary processes, such as constraining reaction mechanisms of minerals, magma ascent rates, or flow of mantle rocks. Recent analytical, experimental, and computational advancements have significantly extended the range of conditions and materials that can be studied, offering new insights into the kinetics of different processes across diverse geological settings.

This session will cover all diffusion-related processes, including diffusion chronometry studies, experimental quantification of diffusivities, diffusion-driven stable isotope fractionation and other areas of applicability such as geospeedometry. We welcome studies from broad geological contexts, from planetary interiors and Earth’s mantle to shallow magmatic and volcanic environments. We particularly encourage new methodological, analytical, theoretical or experimental approaches.

We are at the beginning of an observational revolution in exoplanet science. The advanced capabilities of JWST, ALMA, and upcoming large ground-based observatories will allow us to better characterize physical properties of exoplanets, their atmospheres, and their host stars. This information will allow us to place Earth and our solar system’s other rocky bodies in the wider context of planet formation and evolution in the universe. Based on our current understanding, the most common types of planets are sub-Neptunes and super-Earth (planets with masses in between those of Earth and Neptune) for which we have no analog in our Solar System. The chemical properties of exoplanets are expected to be diverse, from their interior structures to their atmospheric compositions, all of which are shaped by the chemical environment in protoplanetary disks and subsequently modified by processes throughout a planet’s evolution. A comprehensive understanding of exoplanet demographics and of what exoplanets are likely to be habitable requires interdisciplinary knowledge across geochemistry, meteoritics and cosmochemistry, astronomy, planetary science, mineral physics, biogeochemistry, and extremophile biology. In this session, we invite contributions spanning theoretical, experimental and observational research that seeks to improve our understanding of the chemical properties of exoplanets and protoplanetary disks.

This session aims to celebrate the scientific achievements and outstanding contributions made by Catherine Chauvel and Dominique Weis to our understanding of mantle geochemistry.

The chemical composition of the Earth’s mantle has continuously evolved since the formation of the Earth. Early differentiation, continental crust extraction and subduction of oceanic plates and sediments have generated chemical heterogeneities that are nowadays sampled in a wide variety of geodynamic settings (arc, mantle plumes, large igneous provinces, etc.). Elemental and isotopic analyses, including radiogenic (Sr, Nd, Pb, Hf, W, noble gas) and stable isotopes (Li, C, O, S, Fe, Tl) of mantle-derived rocks are keys to gain insights into mantle composition and its evolution through time, the preservation of early-formed mantle reservoirs, crustal recycling processes, and core−mantle interactions. We encourage all contributions from geophysics, petrology, numerical modelling, and geochemistry to build a deeper understanding of the composition of the Earth’s mantle.

Sulfur’s multivalent character and its ability to form gas, liquid and solid phases in magmatic, aqueous and atmospheric conditions make it an important driver of geological processes occurring at planetary surfaces and interiors. Over geological timescales, chemical reactions involving sulfur play a major role in the evolution of life and the atmosphere. At depth, the behavior of sulfur during magmatic and hydrothermal processes governs the mobility and distribution of chalcophile elements and influences ore-forming processes. Earth’s sulfur cycle involves outgassing of mantle-derived sulfur to the surface via volcanoes, low-temperature processing at or near the surface, and return of sulfur to the mantle at subduction zones. Large uncertainties remain regarding the fluxes of sulfur between different terrestrial reservoirs, and how these may have varied throughout Earth’s history.

In this session we welcome contributions aimed at understanding various aspects of the sulfur cycle from core to surface, including petrological, geochemical, experimental, and theoretical approaches. Topics of interest may address the distribution of sulfur isotopes in the Earth’s mantle, sulfur partitioning between silicate melt, sulfide and/or sulfate melts or minerals and fluids in magmatic systems, either using experiments or natural samples. We welcome submissions discussing the fate of sulfur in hydrothermal systems, sulfur’s role in ore deposit formation, its volcanic degassing behavior, its potential role in the early Earth, and isotopic variability through time. We also welcome studies of sulfur on other planetary bodies which highlight its unique magmatic and geochemical behavior.

Earth materials, including minerals, fluids, and melts, constitute the planet’s interior. Investigating the physicochemical properties of these Earth materials is key to understanding related geological processes which include, but are not limited to, ore deposit formation, climate change dynamics, earthquake genesis, mantle convection and plate tectonics, and volcanic activity. While natural rocks offer invaluable insights into these processes, their records are often incomplete or altered by subsequent geological events. Thus, independent approaches are required to complement traditional geological and geochemical analyses, such as lab experiments conducted under controlled conditions and computational modeling. In addition to geochemistry, geophysical measurements, which are essential for elucidating the structure of planetary interiors, are influenced by the physicochemical properties of Earth materials which vary over the wide range of pressures, temperatures, and compositions across planetary bodies.

In this session, we celebrate the illustrious career of Dr. I-Ming Chou, whose pioneering work has significantly contributed to our understanding of the behavior of Earth materials through laboratory experiments. Such experiments are essential for comprehending field-based geochemical and geophysical observations, and I-Ming's contributions have facilitated advancements in numerous domains, including geochemistry, mineralogy, fluid inclusions, gas hydrates, mineral deposits, petroleum geology, environmental science, deep-sea research, and planetary science. In recognition of I-Ming's work, this session invites a diverse array of submissions that explore a variety of geologic processes through the lens of the physicochemical properties of Earth materials. We warmly encourage submissions from various research approaches, including laboratory experiments, field-based studies, and computational simulations.

Lithospheric and asthenospheric mantle reservoirs preserve unique geochemical and geodynamic information about the evolution of continents. These mantle reservoirs are also increasingly recognized to exert strong control on water and volatile element fluxes (e.g., carbon, nitrogen, halogens, noble gases) between the deep Earth and crust, acting as the interface in geochemical cycles over short and long timescales (e.g., CO₂-degassing versus diamond formation). The redox state of the lithosphere–asthenosphere boundary region profoundly affects melt reactions and the dynamic stability of continental roots, but links to redox processes in the deeper mantle remain unclear. Primitive intraplate magmatism (e.g., kimberlites, carbonatites, lamproites, alkaline basalts, komatiites) is strongly controlled by lithospheric architecture and redox state, and to variable extent sourced from the lithospheric mantle. Magmatic processes, including redox melting and freezing, metasomatic interactions and melt migration near the lithosphere–asthenosphere boundary, can further promote lithosphere thinning and continental breakup. Understanding the many facets of mantle lithosphere evolution and their implications for plate tectonic and geochemical cycles requires a broad yet united approach, anchored in experimental studies and in investigations of natural samples (e.g., primitive magmatic rocks, xenoliths, diamonds). Steve Foley’s research has pioneered the ‘all-inclusive’ approach, and in this honorary session we will bring together current topics in the fields of petrology (including experimental approaches), geochemistry, geophysics and numerical modelling devoted to unlocking the deep and secular records of continent evolution, volatile cycles and mantle-derived magmatism.

Proterozoic ophiolites and other arc-related magmatic rocks are extremely crucial for understanding the tectono-magmatic processes that have shaped continental crust generation and assembly. During the Proterozoic, the development of subduction zones was pivotal for continental growth and stabilization, leading to the assembly of supercontinents such as Rodinia. These events often involved fragments of oceanic lithosphere being emplaced and accreted along continental margins, termed as Ophiolites: the only surviving relics of paleo-oceanic lithosphere. These zones of amalgamation are now found as large-scale continental shear zones that are present in all cratonic landmasses of the world. These shear zones have also facilitated ore genesis by providing excellent conduits for hydrothermal circulation, leading to some of the world’s best deposits of base and transition metals like Pb, Zn, Cu, U, Ni, and PGEs. Hence, they are vital for understanding the processes that have guided continental lithospheric evolution, thermal and chemical evolution of the mantle, and the intense deformation and metamorphism that led to their formation. We welcome submissions employing a variety of traditional and innovative approaches and disciplines, including field observations, petrology, geochemistry, geochronology, and modeling. We seek a broad and interdisciplinary perspective on topics such as (but not limited to) ophiolites and other arc-related intrusives, their recognition in the Proterozoic rock record through a combined petrological- geochemical-isotopic approach, petrogenetic studies of such assemblages deciphering the nature of magma generation and storage, and magma chamber processes, as well as melt/fluid-rock interactions and hydrothermal circulation leading to ore genesis.

Earth records a complex evolution spanning ca. 4.5 billion years. Reconstructing the history of our planet and understanding its fundamental processes hinges on our ability to accurately constrain geological time. Recent progress in geo- and thermochronological research has spawned new analytical techniques and strategies for applications, leading to an increase of viable mineral-decay-system pairs and novel dating schemes combining geochronology with thermochronology or additional mineral characterization. These advances enhance our capacity to put an age to specific processes such as crystal growth, mineral reactions, exhumation-related cooling, or deformation along fault zones. This session’s goal is to discuss the novel methods needed to take Earth’s pulse, the development of new analytical instrumentation, their application to unravel geological history as well as improvements in data handling. We particularly encourage the application of novel approaches to constrain the timing and rate of geological processes, including (but not limited to)studies using U-Pb, Rb-Sr, Lu-Hf, Re-Os, Raman, fission-track, and noble gas isotopic systems.

Understanding the physical and chemical processes that form Earth’s continental crust, and how it evolves, is critical for understanding Earth history, structure, dynamics, resources, chemistry, and seismology. In contrast to the more accessible upper crust, the composition and formative processes of the lower crust remain uncertain.  Also, the relative importance of igneous input and differentiation, (ultra-)high temperature (UHT) and (ultra-)high pressure (UHP) metamorphism, partial melting, melt extraction, density sorting, tectonic working, weathering, and fluid migration are unclear. Multidisciplinary field and laboratory studies, encompassing structural, petrological, geochemical, isotope analyses and the geo/thermochronology of (U)HP-(U)HT rocks, are key to developing a process-based framework for the chemical and physical evolution of the continental crust. This session welcomes contributions related to lower crustal igneous, metamorphic and geodynamic processes, that shed light on the timing, formation and evolution of lower crustal rocks and their significance to regional and global tectonics. Submissions from researchers at all levels, including PhD students, are warmly welcomed.

The intricate relationships between deformation, metamorphism, and mineralization are key processes that shape the Earth's crust and drive the formation of economically significant mineral deposits. The present session will focus on the dynamic interaction between deformation, metamorphism, and mineralization: three fundamental geological processes. Deformation, resulting from tectonic forces, changes the Earth's crust through folding, faulting, and fracturing, creating structures that often serve as conduits for mineralizing fluids. Metamorphism under varying conditions of temperature, pressure, and fluid activity, is also be highlighted as a process that transforms pre-existing rocks’ mineralogy, and texture, leading to the concentration and redistribution of valuable minerals. This session will explore the role of fluid flow, heat, and pressure in mineralization processes along with the application of isotopic dating and geochemical analysis in understanding mineralizing events and their timing. The critical interplay among these processes is crucial for understanding the geological evolution of the Earth and for identifying mineral resources. The session will further reflect an overview of practical approaches for mineral exploration and resource assessment, with case studies from around the world. Overall, this session will provide an inclusive overview on linking structural geology, metamorphic petrology, and economic geology, to get a comprehensive understanding of how deformation and metamorphism create favorable conditions for mineralization, shaping the distribution of natural resources. It emphasizes the importance of these processes in geological research and resource exploration, highlighting their role in both the formation of the Earth's crust and the development of mineral deposits essential for technological and industrial applications.

The exchanges of mass and energy between the oceanic lithosphere, seawater, and the sub-surface biosphere are an important but poorly understood component of many global (bio-)geochemical cycles. Key uncertainties on the dynamics of these interactions include (1) the duration, rates and magnitudes of exchange that occur during hydrothermal circulation in the oceanic lithosphere (2) the penetration depths of seawater-derived fluids and deep microbial life beneath the seafloor in different types of crust and (3) the influence of crustal architecture, spreading rate, and basement ventilation on all these variables. Scientific drilling (e.g. IODP Expeditions390–393, 395, 399, Oman DP) and other sampling of the seafloor and ophiolites have successfully recovered samples from a range of tectonic contexts. As a result,many uncertainties surrounding lithosphere–hydrosphere–biosphere interactions are now primed for quantitative study. Crucially, this generation of sampling was accompanied by robust microbiological sampling programmes. Parallel geochemical advances in isotopic analysis have established a platform for powerful joint petrological–geochemical–microbiological investigations. In order to enable continuing research post-JOIDES Resolution, it is essential to utilize these samples to maximum effect, establishing biomarkers amenable to application to legacy materials.  This session provides a forum for presentation of results on these topics,emanating from drilling projects and other studies of oceanic lithosphere. In particular, the session aims to build collaborative links between geochemists and geomicrobiologists and between different scientific drilling parties working with complementary skill- and sample sets.

Tectonic processes shapes the Earth’s surface, influencing deformation localization, fluid flow, seismicity, and the distribution of resources. Surface processes in these settings are relatively well understood, and advances in seismic imaging have revealed much about deep lithospheric structures. However, accurately timing deformation events along major fault systems has been challenging, with many reconstructions relying on indirect stratigraphic or cross-cutting relationships. Recent advancements in in-situ dating, particularly high-resolution carbonate methods, now allow for precise dating of texturally complex samples, offering new insights into the timing and mechanisms of crustal deformation.This session aims to explore the integration of isotopic and geochronological data across various geological settings, shedding light on fluid-rock interactions, tectonic activity, and the interaction with the crust. We invite contributions that apply techniques such as U-Pb, U-Th, and Rb-Sr dating, from high-resolution (e.g., LA-ICPMS) to high-precision (ID-TIMS) methods, to unravel the intricate isotopic behavior, texturally complex samples with multi-phase growth, long digenic history, and microscale structural context. Emphasis is placed on multidisciplinary approaches that combine field studies with isotopic data to investigate fault systems, fluid pathways across diverse tectonic, hydrothermal and sedimentary environments. This session aims to foster dialogue among researchers and advance geodynamic, metallogenic, and paleotopographic reconstructions.

Stable isotopes provide new opportunities to improve our understanding of the diversification of Earth’s reservoirs and elemental cycling between them. Equilibrium and kinetic stable isotope fractionation between minerals and fluids/melts and mixing between different sources cause variations in stable isotope compositions. Knowledge of these mechanisms can illuminate various processes shaping the Earth’s lithosphere, including interactions with the mantle and surface reservoirs. We aim to bring together researchers from diverse backgrounds who seek a better understanding of stable isotope fractionation, both traditional and non-traditional, and leverage it to develop new tools for deciphering processes across all scales within the geologic record. This includes several key aspects to be addressed, such as (1) mineral-scale quantification of equilibrium stable isotope fractionation factors and diffusion-driven isotope fractionation; (2) development of methods based on stable isotope fractionation, including geothermometers and other proxies, and source fingerprinting schemes; (3) investigation of the interaction between Earth’s crust and surface processes, including weathering, sedimentation, and biological activity; and (4) quantifying and interpreting stable isotope compositions to constrain macro-scale processes related to lithosphere evolution, such as subduction recycling, interactions with the mantle, igneous differentiation, and potentially associated ore deposit formation. We thus welcome analytical, experimental, and theoretical contributions addressing these topics. By exploring these themes, the session will provide an integrated perspective on the behavior and applications of stable isotopes for decoding the complex processes on all scales shaping Earth’s lithosphere and related reservoirs.

Mantle melting, mantle metasomatism and crust-mantle interactions are fundamental processes controlling the physicochemical evolution of the mantle, both in oceanic and in continental plates, including its solidus location, rheology and longevity, as well as fertility and metallogenic fingerprint. Subduction and ultimately collision at plate margins introduces heterogeneity at all scales. After continent breakup, the complex evolution of the oceanic lithosphere, including the oceanic crust accreted in mid-ocean ridges, is a reflection of mantle convection and plate motion occurring in different geotectonic contexts.

Xenoliths in continental and oceanic intra-plate setting, as well as orogenic peridotites and ophiolites exhumed at convergent margins represent direct “windows” into these processes,while mantle-derived melts provide valuable indirect information. This session seeks to share expertise from all of these settings to discuss a broad range of topics, including (1) evidence for fluid-rock interaction and melting in bulk mantle rocks, their minerals and solid, fluid or melt inclusions, (2) the nature and physicochemical conditions of elemental and isotopic exchange between crust and mantle, (3) constraints on depth, degree and extent of metasomatism, (4) compositions and formation conditions of mantle-derived melts with implications on their (metasomatised) sources, (5) the complexity of oceanic crust evolution arising from active plumes, as well as recycled and variably processed oceanic and continental material. We invite contributions from all domains of geosciences that elucidate processes that increase the heterogeneity in the lithospheric and the convecting mantle, such as igneous, metamorphic and experimental petrology, ore geology, numerical and thermodynamic models, geophysical observations, geodynamics and more.

This session aims to explore the formative stages of Earth’s evolution, focusing on the critical processes that transformed the planet from its molten origins to a stable lithosphere capable of supporting life. Central to this theme is understanding the origin and evolution of Earth's early crust, mantle, surface environment, and dynamics, through the study of preserved cratonic lithosphere and via modelling techniques. We aim to foster interdisciplinary dialogue among researchers to build a cohesive understanding of Earth’s early evolution. Contributions are encouraged from a wide range of disciplines, including petrology, geochemistry, isotopic studies, geobiology, geochronology, structural geology, geodynamic modelling, and experimental petrology, all working together to construct a comprehensive picture of early Earth’s dynamic history. Key topics include (but are not limited to): understanding the Earth’s magma ocean stage and its implications for primary mantle heterogeneities; timeline and mechanisms behind the formation of Earth’s first primordial crust, the formation and evolution of felsic crust and the cratonic lithosphere; greenstone belts as records of biosignatures, and surface processes; and Precambrian geodynamic settings. We invite contributions from researchers at all career stages and look forward to a vibrant exchange of ideas that will advance our understanding of Earth's early history and its evolution into a habitable planet.

This session celebrates the scientific achievements made by Professor Chris Harris throughout his distinguished academic career. Prof. Harris is a renowned stable isotope geochemist with a special interest in oxygen isotopes. Through his research leadership and mentorship over > 4 decades, Prof. Harris has pioneered and expanded the application of oxygen isotopes to answer diverse questions across the many disciplines of geochemistry.

In addition to oxygen, stable isotope systems such as Li, B, Mg, Fe, Cu, Ni, Cr, K, and Si are increasingly used to trace both high- and low-temperature geochemical processes. These systems show great utility in unravelling mantle and crustal processes and can help resolve the role of crustal assimilation, melting and crystallization, metamorphism, devolatilization, diffusion, and metasomatism and fluid-assisted processes in volcano-magmatic systems.

In this session, we invite submissions of studies employing stable isotopes that: (1) contribute to our basic understanding of natural systems via experimental and theoretical studies (e.g. isotopic fractionations, and/or diffusion chronometry), (2) address scientific questions relating to how magmas evolve from their source to the surface (i.e. magma generation and differentiation), and (3) constrain post-magmatic and metamorphic processes such as low-temperature alteration. Results of developments in analytical techniques and standardization are encouraged, as well as global syntheses across systems and timescales. We aim to foster diversity and inclusion in our session and strongly encourage contributions from early career researchers and those from groups that are underrepresented in the geoscience community.

The record of Large Igneous Provinces (LIPs) is continually expanding back in time and now includes events older than 3 Ga. Associated with this expanding LIP record, there is now an increased understanding of LIP plumbing systems and origin (typically associated with mantle plumes). LIPs are now recognized to have played a key role in major geodynamic processes, including formation and evolution of the lithosphere, and supercontinent breakup. These important phenomena also frequently coincide with complex environmental changes, including mass extinctions, oceanic anoxic events, hyperthermal events, global glaciations, regional topographic changes, ore deposit formation, and significant silicic magmatism (SLIPs), carbonatites and kimberlites. We welcome contributions from a diverse range of disciplines to encourage cross-fertilization of ideas and a multi-faceted discussion of LIP systems, including igneous and sedimentary geochemistry, experimental petrology, geochronology, and studies utilizing chemical and biological proxies in the stratigraphic record. Novel and provocative contributions are particularly encouraged, as well as those from groups underrepresented in the geoscience community.

Recent eruptions at Etna, on La Palma, Hawaii, and on the Reykjanes Peninsula in Iceland are prime examples where high-resolution syn-eruptive sampling has been applied to better understand magma supply and eruption patterns in populated areas threatened by active volcanism. Detailed time-resolved sampling of erupted lavas and associated pyroclastic products allows systematic investigation of changes in mineralogical, chemical, and isotopic characteristics on a daily to weekly timescale, giving the opportunity to correlate this information with physical volcanology plus geophysical and geochemical monitoring information. This can be utilized to more fully understand changes in eruptive patterns and styles and to help civil protection efforts. High-resolution sampling of ongoing eruptions offers an exciting approach to advance our knowledge of the inner workings of volcanic systems as well as to better understand and prepare for changes of eruptive style and phenomena. We invite contributions that utilize time-resolved volcanological, petrological, geochemical, and isotope data that can serve to better understand volcanic processes and help adjust actions required to reduce risk for infrastructure and society.

In subduction settings, calc-alkaline magmatic systems are the primary mechanism of new crust generation and are responsible for the majority of explosive volcanic activity. These systems are also instrumental in the generation of Cu-porphyry deposits of economic significance. This session focuses on all aspects of calc-alkaline magmatic systems—from the magma source, mechanisms of magma transport and assembly, and chemical differentiation, to the exsolution of fluids and the precipitation of mineralized (or non-mineralized) phases. We invite contributions that address these topics from a variety of perspectives, including natural case studies, experimental approaches, and numerical and thermodynamic modelling. Topics of interest include, but are not limited to: magma source characteristics and melting processes in subduction zones; magma storage, ascent, and emplacement mechanisms; chemical evolution and differentiation of magmas through fractional crystallization, mixing, and assimilation; the role of volatiles; the timescales of magmatic and hydrothermal processes.

Magmas represent mixtures of liquids, solids, and gases that undergo complex processes during their ascent from the mantle to shallower levels. Understanding magmatic plumbing systems is fundamental to unravelling key processes driving volcanic eruptions, crustal evolution, and mineralisation with critical metals. Recent advances in analytical, experimental, and computational modelling techniques provide new insights into magma storage, transport, and differentiation. Ongoing research efforts aim to more accurately constrain the complex architecture of magmatic plumbing systems, investigate the evolution of magma storage systems in space and time, and quantify dynamic processes leading to eruptions. Current challenges include understanding relationships between crystals and melts, estimating magma storage depths, improving computational approaches to simulate magmatic systems, and generating experimental observations to meaningfully calibrate these models and interpret natural systems.

In this session we invite contributions aimed at improving our understanding of magma generation, transport, storage, and evolution processes. These contributions may draw on any combination of field observations, mineral-textural petrological investigations, high-resolution geochemical analysis, geophysical data integration, thermodynamic and numerical modelling, machine-learning, and experimental petrology. We especially welcome innovative contributions that integrate different approaches as well as studies that develop and refine petrological tools needed to enable a deeper understanding of magmatic plumbing systems and magma evolution.

This session is sponsored by the IAVCEI commission of Volcanic and Igneous Plumbing Systems (VIPS).

Magmas and fluids largely escape from Earth’s interior to the surface in volcanic and seismically active regions. Recent attention has also focused on quiescent volcanoes since multidisciplinary investigations have shown that magma accumulations at depth are coupled with enhanced degassing of volatiles long after the last activity. Furthermore, magma accumulation and fluid transfer in regions far from volcanism play an active role in seismicity.

Melt generation and evolution, volcanic eruptions, and seismicity are controlled by geochemical processes at depth, so they can be recorded by and interpreted from the geochemical signatures of the erupted (or intruded) rocks, minerals, and fluids. In fact, fluids transfer messages to the surface about conditions at depth and geochemical monitoring allows recognition of evolving processes over time (e.g., eruptions and earthquakes). Great strides in geochemical monitoring were achieved by the first pioneering activities of the ‘60s-80s, and now we are approaching an interesting phase where the gas/fluid geochemistry and petrology can be used interactively in a multidisciplinary context for improving our understanding of magmatic and seismogenic processes.

We encourage submissions from a broad array of disciplines that bear on magmatic and earthquake-related processes, including geochemistry, petrology, melt-fluid inclusions, thermobarometry, and geochemical modelling, together with new field and lab technologies and methods of data integration and interrogation (e.g., artificial intelligence). Therefore, we welcome diverse approaches from field, analytical, experimental, and theoretical studies that improve our understanding of the geochemical processes that control Earth’s degassing and drive hazardous phenomena such as volcanic eruptions and earthquakes.

The abundances and behaviour of volatile elements during melting, melt transport, and eruption are key to understanding magma generation, melt evolution, and volcanic activity. Fluids, both within magma and as evolved gases and liquids, play a critical role in these processes. The concentrations and oxidation states of major volatiles like CO₂, H₂O, S, and halogens control melting behaviour and the composition of exsolved volcanic gases and fluids. Hydrothermal activity, driven by the interaction of magmatic volatiles with crustal rocks, further influences fluid compositions, mineral formation, and the transport of economically important metals such as Cu, Au, and Sn. The mobility of these metals depends on fluid chemistry, with ligands like Cl⁻ and HS⁻ aiding their transport in hydrothermal systems.

At the eruption stage, the release of gases like SO₂ and HCl has significant environmental impacts, affecting climate and ozone levels. In all cases redox is an important control on fluid and melt speciation and the interactions between oxidation states of iron, sulfur and carbon shape the compositions of melts and the fluid phases they release and residual or fractionating solid phases.

We invite submissions from diverse disciplines—including experimental, analytical, petrological, and theoretical research - to explore the role of volatiles and fluids in magmatic systems. We encourage studies focusing on the volatile compositions and oxidation states of melts, fluids, and gases; fluid-rock interactions; and the development of innovative experimental, analytical, and computational methods for studying volatiles on Earth.

Alkaline magmatism is remarkably diverse, including igneous rocks ranging from ultrabasic to intermediate and from sodic to ultrapotassic compositions. Some of them derive from low-degree partial melting of exotic mantle sources, while others show highly evolved characteristics associated with prolonged fractional crystallization or magma unmixing processes. In addition, magmas can also bear evidence of substantial assimilation of sedimentary rocks at shallow crustal depths, which can strongly modify the original compositions. Widespread “common” SiO₂-undersaturated alkaline rocks commonly are tied with more exotic magma compositions such as kimberlites, melilitites, lamproites, lamprophyres, kamafugites and carbonatites.

This session aims at exploring the nature and petrogenetic connections of a wide range of alkali-rich rocks, ranging from SiO₂-oversaturated (e.g., granites/rhyolites) to more common SiO₂-undersaturated intermediate, (foid syenites/phonolites) to basic-ultrabasic compositions (foidolites/foidites, kalsilite-bearing rocks, melilitites/melilitolites), and their relationships with strongly ultrabasic (kimberlites, ultramafic lamprophyres) and even SiO₂-free compositions (carbonatites). Furthermore, their not-rare association with ore mineralization makes alkaline igneous rocks and carbonatites significant sources of numerous critical raw materials, adding interest in the view of moving towards alternative energy sources. To generate a holistic understanding of these significant rocks a multilateral approach is needed.

We encourage participants to submit and present their field work studies and analytical investigation but also experimental studies and numerical calculations, regarding research on alkaline rocks and carbonatites. The scope of this session covers the origin, evolution, emplacement styles, alteration, mineralization and interaction with crustal lithologies of this large family of rocks.

Humanity has a long-standing relationship with metals, with the advancement of human society closely tied to how we extract and utilize them. Today, as we push for a green energy transition to address climate change, the demand for critical metals, minerals, and raw materials continues to rise due to their essential role in renewable and clean energy technologies. Ensuring the traceability of these critical resources has become crucial for promoting responsible sourcing and sustainable practices throughout the supply chain. Equally important is the study of historical metal products and raw materials, as well as the investigation of past manufacturing processes to better understand historical economic activities and their connection to climate conditions.

This session will focus on the development of geochemical methods and the multivariate analysis of geochemical data to trace the origins of metals, minerals, and raw materials across both ancient and modern times. We welcome contributions on a wide range of techniques, such as MC/SC/TOF-ICP-MS, EPMA, SEM, XRF, and LIBS, that are employed in elemental and isotopic analyses for developing geochemical fingerprints. Topics may include but are not limited to fingerprinting and archaeometallurgical studies of gold, silver, copper, and gemstones, as well as spatial differentiation of ores, and the tracking of critical materials like lithium, cobalt, nickel, graphite, and rare earth elements (REEs) throughout modern industrial supply chains.

Nuclear waste and spent fuel packages at future nuclear repositories are expected to release substantial amounts of heat, due to their initial, thermal loading and radioactive decay heat over time. This will result in elevated temperatures in the engineered barrier systems (EBS), surrounding nuclear waste and spent fuel canisters, which may further lead to hydrothermal alterations of waste canister materials, like copper or steel, or mineral transformations in barrier systems. Additionally, altered solids and elevated temperature conditions may affect the potential release, sorption and transport of radioactive contaminants from canisters across the barrier system, and into the near and far field.. Experimental studies investigating solid alteration processes under repository-relevant conditions are rare and inherently challenging, but highly needed in order to provide a robust scientific basis for repository design and the development of performance assessment models. Dr. Florie Caporuscio dedicated his career to developing experimental setups and performing experimental studies to investigate these, and similar, questions.

In this session, we will celebrate Dr. Caporuscio in his role as researcher and mentor, especially in support of female scientists, by highlighting recent advances in hydrothermal solid alterations and temperature effects in future, nuclear waste repositories and other, extreme environments, based on experimental and/or modeling studies. We especially welcome submissions from collaborators, former mentees, and anyone whose research has been inspired or advanced by the work of Dr. Caporuscio. Humor highly welcome!

Large igneous provinces (LIPs) and alkaline rocks, including carbonatites, represent products of terrestrial magmatism that can host important economic resources. In particular, such rocks are known for anomalous enrichment of transition metals and critical minerals, as well as offering potential for carbon sequestration and green hydrogen production. This session will showcase the processes that form LIPs and alkaline rocks, focusing on the interplay between magmatic and hydrothermal processes. Topics include magma generation, metal enrichment processes, ore genesis, climate impact, and novel economic uses for LIP- and alkaline-related rocks. Contributions are invited on petrogenesis, tectonic settings, mineralogy, geochemistry, isotope geochemistry, and advanced exploration techniques. By integrating these topics, we aim to advance understanding of the formation of economically important LIPs and alkaline rock systems.

Geochemistry is a commonly overlooked aspect of carbon capture and storage even though water-gas-rock interactions are fundamental to the success of such efforts. The injection of CO₂ to the subsurface system leads to perturbations provoking a plethora of geochemical processes which can be both favourable and unfavourable. This session highlights the importance of geochemistry to carbon capture and storage efforts and provides a forum to exchange the latest advances in this field.  This session will address the geochemical aspects of CO₂ capture and storage as part of industrial or natural processes, using experimental, numerical, and field research across 10+ orders of observational scales.  We welcome contributions on (1) laboratory and field experiments, (2) direct air capture using mineral cycling, (3) geochemical responses to CO₂ injection into saline aquifers – including extents of salt precipitation due to formation fluid drying, and the long-term integrity of impermeable caprocks, (4) subsurface mineral carbonation – including novel CO₂ injection methods, -solutions for non-condensable gases, natural analogues, enhanced mobility of trace elements, -past, present and future case studies, and reactive transport modelling of subsurface systems, and (5) development of novel isotopic tracers to quantify the amount of mineralization and the role of bacteria.

Engineered and nature-based Carbon Dioxide Removal (CDR) technologies are currently being explored on land and in the oceans, including afforestation, enhanced soil carbon, terrestrial and coastal enhanced weathering (EW), carbon mineralisation, ocean nutrient fertilization and ocean alkalinity enhancement (OAE), to help achieve net-zero Greenhouse Gas emission goals. These methods not only remove CO₂ from the atmosphere but also offer additional environmental benefits like biodiversity and ecosystem protection, water conservation, and improved soil and ocean health. However, scaling these solutions effectively requires deep geochemical insights, advanced modelling techniques and robust monitoring, reporting, and verification (MRV) across both academia, industry, and policy makers.  We welcome contributions on (1) geochemical site identification, focusing on how geochemistry and predictive models can identify optimal sites for CDR implementation, considering factors such as soil mineralogy, hydrology, and ecosystem potential for EW and OAE; (2) environmental monitoring, especially those studies that highlight the use of geochemical tools to track changes in carbon removal, soil and water health, and marine chemistry; (3) measurement, reporting, and verification (MRV) frameworks, including contributions on innovative geochemical techniques and modelling approaches used to verify carbon removals, such as isotopic analysis and marine alkalinity assessments, ensuring the reliability and durability of CDR efforts.

Hydrogen and helium are key components in the energy transition and their potential as natural resources is driving an upsurge in exploration and research to understand the pathways, kinetics, and mechanisms of geologic hydrogen and helium generation, migration, and storage. Ensuring future supply of hydrogen and helium requires interdisciplinary studies spanning multiple length and time scales by experimentalists and modelers to resolve. Research is also necessary to constrain the impacts of unintended release and degradation on aspects of Earth’s biogeochemical cycles. This session aims to bring together geoscientists, modelers, and industry experts to discuss the physical and chemical behaviors, resource potential, and exploration and evaluation technologies for hydrogen and helium.

This session welcomes submissions on 1) pathways, kinetics, mechanisms, and enhancement of geologic hydrogen generation; (2) geochemical and mineralogical characterization of fluids, minerals, rocks, and gases; (3) hydrogen monitoring, separation, transport, and storage; (4) biotic and abiotic hydrogen consumption; (5) the potential for carbon capture.

Global development and the energy transition are fundamentally tied to the availability of critical and strategic metals such as copper, cobalt, nickel, and rare earth elements. Non-traditional resources have the potential to play an important role in meeting the significant and growing demand for critical minerals. Non-traditional resources include mine tailings, industrial waste streams from existing mines, coal mine drainage, and organic-rich sedimentary rocks such as black shale, coal, lignite and oil shale. This session aims to illuminate pathways and catalyse interdisciplinary dialogue towards a more sustainable and resource-efficient future by presentation and discussion of field, laboratory, and/or modeling studies of critical mineral production from non-traditional resources.

Submissions are welcome that focus on (1) geochemical processes controlling the enrichment of metals and rare earth elements in non-traditional waste streams, (2) bio- and/or geochemical technologies for extracting metals from waste streams, (3) the impacts of non-traditional waste streams on the environment, (4) socio-economic assessment of metal extraction from industrial geochemical waste, and (5) opportunities and challenges in industrial geochemical waste valorisation.

Lithium has emerged as one of the most critical metals driving the global energy transition. It is mined from geological resources including pegmatites, granites, clays, and brines. Advancing our understanding of lithium enrichment in igneous, sedimentary, and geothermal systems, as well as the formation of these deposits, is essential to support the exploration and discovery of new resources to meet growing demand.

This session seeks to foster collaboration among lithium geochemists, mineralogists, and economic geologists, bridging the knowledge gap between lithium in hard rock and fluid systems. We warmly welcome interdisciplinary submissions exploring lithium cycling within source-to-sink pathways, lithium geochemistry, and mineralization across both conventional and unconventional deposits. Contributions focusing on geometallurgy, innovative recovery technologies, and strategies to minimize the environmental impact of lithium mining are also encouraged.

Natural fluids transport and re-distribute elements in a wide range of geologic environments and fluid-rock geochemical interactions play a critical role in the evolution of both natural and engineered subsurface systems, including geothermal reservoirs, ore formation, geological storage of nuclear waste, CO₂ sequestration and geological energy storage of H₂, compressed air and biomethane. Our understanding of element mobility in fluids depends greatly on our ability to quantify and model the processes occurring in the aqueous medium and during fluid-rock reactions at scales ranging from those of the molecular species, through pore-scale studies, to those of large geothermal fields, ore deposits, and assessment of processes occurring in waste repositories and storage facilities.

This session welcomes submissions that will include, but not limited to: (1) theoretical, computational, and physics based machine learning models and experimental studies of hydrothermal fluids, gas-mineral-fluid interactions, and aqueous speciation in natural and engineered systems including molecular-level modeling of hydrothermal fluid properties, (2) reactive transport processes in fractured or porous rocks, focused on understanding of the spatial and temporal aspects of hydrobiogeochemical processes, and (3) large scale genetic models of geological deposits, engineered systems, etc.

Geochemical mapping is an essential tool in any study concerning Earth’s surface, regardless of scale. In an era where mineral raw materials play a critical role in the energy transition towards a greener society, regional geochemical mapping is particularly valuable to reveal metallogenic provinces with high ore potential. At more local mapping scales, geochemical studies can be directed towards identifying the provenance of certain elements or groups of elements. These local-scale geochemical surveys provide greater detail, offering insights that can be crucial for understanding the primary and secondary distribution and behaviour of elements, including mine tailings, which are becoming a valuable potential resource. The flexibility and applicability of geochemical mapping across various scales and disciplines underscores its indispensable role in mineral resource management. This session invites contributions on all aspects of mineral resource management including secondary resources.

Submissions are welcome that focus on (1) exploration targeting for new mineral deposits, and (2) improving metal recovery from both primary ores and mine wastes.

Metallogenesis plays a critical role in unraveling the complex processes that govern the formation, localization, and evolution of mineral resources. Significant amounts of mineral resources are associated with hydrothermal systems varying from magmatic-hydrothermal to basinal environments. As global demand for metals continues to rise, driven by technological advancements, the green energy revolution, and the pressing need for sustainable development, the study of economically important ore-deposits is fundamental. This includes, but is not restricted to, porphyry Cu-Mo-Au, granite-related Sn-W, pegmatite-related Li and rare metals, alkaline rock-carbonatite-related REE and high-field strength elements, clastic-dominated (CD-type) and Mississippi Valley-type (MVT) Zn-Pb, stratiform sediment-hosted Cu-(Co), sandstone-type U, unconformity-related U, and banded iron formation (BIF) related Fe deposits. In recent years, significant advances have been made in understanding processes and parameters governing metal extraction, transportation, deposition and mineralization style in various geodynamic and tectonic environments, boosting metal recovery. This session seeks cutting-edge research related to advances in isotope geochemistry, experimental petrology, geochronology, geochemistry, and modeling of the genesis of ore deposits. This session is intended for scientists working in academia, industry, government agencies and researchers interested in the geology of critical commodities and mineral exploration. By facilitating interdisciplinary discussions and presenting the latest scientific advancements, this session aims to contribute to a deeper understanding of ore geology and highlighting its role in addressing global resource challenges.

Recent instrumentation advancements in (ultra) high-resolution mass spectrometry, particularly Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS), have revolutionized the characterization of complex organic mixtures, spurring a new influx of researchers across many scientific disciplines who seek to leverage unprecedented mass resolving power, precision, and mass accuracy for a wide range of samples. Engineers, oceanographers, biogeochemists, ecologists, hydrologists join analytical chemists to evaluate specific chemical signatures in natural organic matter in surface and groundwater samples, soil samples impacted by natural and anthropogenic disasters, degraded oil from oil spills and natural seeps, biofuels from pyrolysis processes, novel materials, and to identify emerging contaminants (e.g., per-and-poly-fluoroalkyl substances - “forever chemicals”) in a complex environmental sample matrix.

This session invites contributions related to novel hardware or software applications of FT-ICR MS, including petroleomics and (paleo)environmental studies, such as identification of lipid and porphyrin biomarkers as paleo proxies, dissolved organic compound cycling in ecosystems, oil spill transport and fate assessments, and nontargeted evaluation of emerging pollutants within a complex environmental sample matrix, to name a few. Applications of FT-ICR MS related to sustainable fuel production and characterization, and novel and materials are also encouraged.  Finally, we welcome presentations discussing methodological and instrumental advances and challenges UHR-MS technology faces, such as improved quantitation and structural identification, innovations in FT-ICR MS data processing, visualization, and modeling, as well as hyphenated and/or synergistic approaches that leverage other analytical techniques.

We are committed to showcasing transdisciplinary collaborations and contributions from early career, diverse, and underrepresented communities.

This session spotlights innovative geochemical tools and techniques for simple, on-site sampling and analysis of environmental parameters. Emphasizing both real-time data acquisition and efficient methods for later analysis, presentations will cover portable technologies, including field-ready sensors, geochemical sampling devices, and streamlined analytical processes. Participants are encouraged to present real-world examples of how these tools have been applied in environmental and geochemical investigations to improve data coverage and adapt field strategies on-site.

This session invites submissions from researchers who use geospatial analysis to address geochemical challenges. Many geochemistry questions inherently require geospatial solutions, and by integrating these two fields, researchers can significantly enhance the depth and impact of their analyses.

Topics may include technology deployment (ex. carbon dioxide removal), contaminant distribution, resource management, hydrogeology, science communication, or any other areas where geospatial analysis is relevant. All types of geospatial analysis are welcome, whether conducted with software tools like ArcGIS or QGIS, or through programming languages such as Python or R. This session aims to provide an inclusive platform for researchers who utilize these tools or those interested in incorporating geospatial analysis into their work. It offers an opportunity to explore the strengths, capabilities, and limitations of geospatial analysis in solving geochemical problems and effectively disseminating research.

Since the early 2000s, the advantages of the use of ultrashort pulsed lasers in analytical chemistry have been proposed, yet their widespread usage in analytical fields including LA-ICPMS, LIBS, LIMS, APT and their applications to geochemistry and material sciences grew slowly. However, the geochemical community is now ready to make significant advances in both technical development and practical applications of ultrafast laser technologies. This is highlighted by the growing number of laboratories currently operating ultrafast laser systems (or in the process of implementing the technique), as well as the arrival of commercial versions of femtosecond laser from manufacturers in the field of laser ablation technologies.

This session welcomes contributions that 1) present novel methods, instrumentation or techniques that enhance the efficiency and efficacy of femtosecond laser ablation in analytical workflow, 2) address technical challenges associated with ultrafast laser ablation, 3) apply ultrafast laser ablation to answer complex (geo)chemical questions that cannot be answered by traditional nanosecond lasers, or 4) discuss the potential for ultrafast laser ablation to revolutionize analytical methods in geochemistry, including its integration with other analytical techniques and its role in addressing emerging scientific challenges. We aim to foster collaboration, share knowledge and create a community that facilitates the implementation, development and consequent applications of ultrafast laser ablation.

Physics and chemistry of geochemical systems, reactions, and processes is a vibrant and rich research field which incorporates studies of a large class of systems at a wide span of spatial and temporal scales. The analytical and computational tools include, but are not limited to, spectroscopy, microscopy, interferometry techniques, isotope signatures, chemical analysis, as well as Molecular Dynamics, ab initio, Monte Carlo, Lattice Boltzmann, and reactive transport computational methods. Each tool and technique provides details at a specific scale, though understanding the big picture of geochemical systems requires consideration of all relevant properties emerging at all scales revealed by different analytical and computational tools. We invite contributions dedicated to the fundamental understanding of mechanisms driving geochemical systems and processes at any scale, e.g., nucleation, crystal growth, dissolution, adsorption, mineral reactivity, phase transitions, elemental and isotope fractionation, material transport, weathering, water-rock interactions, application of geomaterials in environmental, industrial and medical fields, problem-targeted design of functionalized materials. This session is to honor scientific and societal contributions of Andreas Luttge, who recently retired, into the development of novel concepts and ideas in understanding mechanisms of water-rock interactions. Therefore, we especially welcome novel conceptual methods and findings in fundamental understanding of geochemical systems, including but not limited to rate variability across the scales, nonclassical nucleation, mesocrystals and aggregation, process fingerprint, unusual patterns in geochemical reactions and rocks, element/isotope records, key steps for mineral or rock formation, alteration or decomposition at all relevant scales, and other fundamental questions.

Contamination from xenobiotics, such as industrial chemicals and emerging pollutants, poses growing challenges to both environmental and public health. While advancements in geochemical techniques provide critical data on these contaminants, translating this data into meaningful health risk assessments requires innovative computational approaches. This session focuses on the use of advanced modelling tools such as geospatial analysis and simulations to bridge the gap between environmental contamination and health outcomes, offering valuable insights for effective mitigation and policy development.

We welcome submissions that:

• Present Advanced Computational Models: Apply innovative models, including Bayesian networks and artificial neural networks, to assess environmental contaminants and their bioavailability across ecosystems.
• Integrate Geochemical Data with Epidemiological Frameworks: Highlight methodologies that combine geochemical data (e.g., soil and water analysis) with epidemiological studies and toxicological assessments to predict chronic health outcomes from long-term contaminant exposure.
• Develop Predictive Models: Application of machine learning algorithms, such as support vector machines and random forests, along with Monte Carlo simulations, to model contaminant dispersion and assess exposure pathways.
• Application of Geospatial Analysis: Utilize GIS and remote sensing to identify contamination hotspots and correlate them with spatial health risk patterns in communities.
• Case Studies on Environmental Health Linkages: Present empirical case studies that establish quantifiable links between environmental degradation and public health effects.
• Advancements in Real-Time Monitoring Systems: Showcase IoT-enabled monitoring systems and large-scale data integration techniques for assessing cumulative impacts on human health.

Neutrons and X-rays are powerful probes for the study of structure, speciation and dynamics of minerals, rocks and geofluids, interrogating length scales from atoms to microns and characteristic time scales from pico- to microseconds.  The weak interactions between neutrons and matter allow the study of large samples, and isotope contrast variation is commonly used to highlight specific features in complex samples. The emergence of new, powerful neutron and x-ray sources opens opportunities for novel studies of complex geochemical reactions and processes.  Quantification and understanding of fluid behavior and fluid-rock reactions is important for optimization of large-scale geologic engineering processes such as natural gas and oil extraction from (un)conventional reservoirs, geologic carbon storage, and ion and contaminant transport. Using modern neutron techniques, theory, and simulation tools, geochemical systems are studied with the goal of developing capabilities to predict rates of geochemical processes at the nanoscale and in upscaling and reservoir modeling.

This session will focus on new techniques and studies that help elucidate geochemical processes at all length and time scales. We invite paper submissions that highlight geochemical issues associated with mineral and rock reactions, rock characterization, transport of matter by hydrothermal fluids as well as solid-fluid interactions.

Analyses of gem materials are important for their proper identification. Recent advances in analytical techniques such as APT (Atom Probe tomography) has provided new insights into the formation of unusual gem materials such as nanoparticles in the sapphires as well as the artificially diffused plagioclases. The proper identification of gems is an ever-increasing challenge, especially with harder-to-detect treatments and new demands on geographical origin determination. The particularity of using solely non (or micro)- destructive methods is adding another important parameter. More recently computational approaches are also exploited in the study of gem materials such as for understanding the effect of radiation damage or the colour of fresh-water pearls. For the present session all aspects of gemmology combined with geochemistry are welcomed, as long as they help increase our understanding of gem materials.

Mass spectrometry has a long history in geochemistry and isotope ratio mass spectrometers (IRMS), in particular, are essential tools that enable geoscientists to answer a gamut of questions that enhance our understanding of complex systems. Today, IRMS techniques cover the whole periodic table, and, as a consequence, no element is safe from interrogation!

Methodological developments – including those in the realms of sample preparation/introduction, chromatographic separations, and new reference materials – improve analytical reproducibility, ease of use, and inter- and intra-lab quality control. Technical developments in IRMS, such as those addressing ion sources, collision cells, and mass prefilters on multi-collector plasma instrumentation, are also critical to advancing the use of isotopic tools. All branches of IRMS have also benefitted from developments in collector technologies with high-ohmic current amplifiers, charge-collection current amplifiers and multiple electron-multiplier detectors extending detection capabilities, while improving both analytical precision and accuracy.

This session aims to bring together isotope geochemists using all types of IRMS to present and discuss recent advances and innovations in the field. We invite contributions on novel approaches to the collection of isotopic data, including novel sample preparation and sample introduction techniques, innovative mass spectrometer technologies and designs, and new data reduction strategies. We encourage contributions from early career researchers and those from traditionally underrepresented groups. Submissions of null or unexpected results that enhance understanding of the field are welcome and we are particularly interested in contributions that showcase ‘works in progress’.

Studying nanoscale particles and environments has become critical to understanding geochemical cycles in terrestrial, aquatic, and atmospheric environments. These studies can only be accomplished by recent advances in instrumentation, experimental methods, and data analysis/computation. Imaging and elemental analyses, notably through microscopy and synchrotron facilities, facilitate examination of nanoscale materials and environmental processes (e.g micro- and nanoscale sites in soil and sediments that influence redox speciation, nutrients, and biogeochemical cycles). Advances in mass spectrometry, especially ICP-MS and field-/flow-based separation, enable accurate measurements of mass and size distribution, as well as elemental, mineralogical, and/or organic composition of nanomaterials. These data are essential to understand the role of particles in (bio)geochemical cycles and the mechanisms underlying those processes. Examples of particle-modulated processes include: dispersal of indicator elements from ore deposits, soil weathering and sediment transport, climate and health impacts of atmospheric particles, and the transport and toxicological effects of anthropogenic contaminants. This session will emphasize recent innovations and adaptations in the design and application of novel methodologies applied to particles, colloids, and the (bio)geochemical processes they influence. Areas of interest include, but are not limited to:

• state-of-the-art resources available at user facilities or individual labs to characterize and interrogate the interactions involving nanoparticles, colloids, microbes, and minerals;
• advancements in analytical techniques aimed at accurately measuring the size and composition of geogenic, biogenic, and anthropogenic nanoscale particles including nanominerals;
• adaptations of established techniques from other fields that advance nano-geochemical research.

Geochemistry increasingly relies on accurate and precise measurements of elemental concentrations, isotopic ratios, and volatile content within minerals and glasses using micro- and nano-beam instruments. Compositional variations at (sub-)micron scales can preserve records of crystal precipitation, thermal re-equilibration, melt infiltration, redox conditions, crystal strain, and low-temperature weathering. Radiogenic isotopic ratios can date these events, offering insights into lithosphere-hydrosphere evolution and environmental change throughout Earth's history.

For many microbeam instruments (e.g., electron probe microanalysis, secondary ion mass spectrometry (SIMS), laser ablation-inductively coupled plasma-mass spectrometry, micro-X-ray fluorescence), reference materials are essential for calibration. Even where this is not necessary (e.g., atom probe tomography), reference materials matched to analyzed mineral matrices are valuable for method validation and quantification of accuracy and precision. For Big Data applications, matrix-matched reference materials are crucial for documenting long-term reproducibility and levels of inter- and intra-grain homogeneity.

We invite presentations showcasing recent advancements in the development and characterization of new reference materials for micro-/nano-beam analyses of elemental concentrations, isotopic ratios and volatile content (H, C, N, S, etc.). Topics may include the synthesis and characterization of new reference materials, assessment and mitigation of matrix effects, assessment of homogeneity of existing reference materials, innovative calibration strategies, and applications of new reference materials to address outstanding questions in geochemistry and cosmochemistry.

Unravelling how Earth’s environment, including its climate, oceans, biosphere, and atmosphere, has evolved over time is of key importance in addressing the challenges of climate and environmental change facing society today. The sedimentary rock record represents the primary archive of such changes in the geological past and one of the key paths towards a comprehensive understanding of long-term processes operating in the Earth system. The application of geochemical proxies at varying geospatial and stratigraphic resolutions presents a major tool for determining how Earth’s surface environment has evolved over time.

Recent advances in proxy development have vastly improved our ability to reconstruct paleoenvironments, and paleoenvironmental changes, from the sedimentary record. In particular, the increasing use of non-traditional isotope systems (e.g., chromium, zinc, molybdenum, cadmium, osmium, uranium) has enabled greater understanding of the effects of, and relationships between, phenomena such as climate changes, large igneous province eruptions, oceanic anoxia, and mass extinctions (etc.), as well as positive and negative carbon cycle feedback systems in detail. These tools have also helped to link such observations from paleo-records to modern-day phenomena.

In this session we invite submissions exploring the development and application of paleoclimatic, paleo-oceanographic and/or paleoenvironmental geochemical proxies. We especially welcome submissions which investigate the use of new or non-traditional isotope systems, the integration of multiple proxy systems (e.g. non-traditional & traditional isotope systems) or proxy and numerical model data. Submissions linking the past to the modern are also welcome. We particularly encourage submissions from early-career researchers and scientists from under-represented groups.

The session is devoted to the application of geological and chemical methods to analyze the raw material base of prehistoric and ancient societies, problems of geoarchaeology and archaeometry and the practice of applying mineralogical and geochemical research methods to examine archaeological sites and artifacts. The session is targeted at discussing the results, methodological specifics and limitations of isotopic (Sr, C, O, N) analysis employed to study artifacts and archaeological sites as well as geochemical and isotopic mapping. Mineralogical and petrographic examination of different kinds of artifacts – lithic, wooden, bone and ceramic – is of interest, as well as multidisciplinary study on climatic reconstruction, climate change and its impact on prehistoric human adaptation and dispersal. The session is supposed to discuss the results of pioneering works, focused on development of geochemical methods for sampling and further pretreatment and its application in archaeology.

The Ediacaran-Cambrian Transition (ECT, ca. 575 Ma to 520 Ma) encompasses one of the most remarkable intervals of Earth’s history. After billions of years, life in the ocean moved from simple single and multi-celled forms to macro-organisms with complex body plans that include the earliest soft-bodied and skeletal metazoans. The dawn and rise of animal life culminated in the diversity of phyla we see today. Despite recent advances, palaeoenvironmental changes in the Earth System that may have been responsible for the origin and diversification of animals remain enigmatic, as do the influences that new biota may have imposed on planetary climate and biogeochemical cycles. Understanding these changes requires a multidisciplinary approach that considers the co-evolution of life and environment and animal-planet interactions. This session welcomes submissions that aim to understand the Earth System and biospheric change during the ECT using new insights from geochemical, paleobiological/ecological, stratigraphic and sedimentological, geochronological, and/or numerical modelling data. This session will be partly dedicated to submissions that share new data from the International Continental Scientific Drilling Project (ICDP) ‘Geological Research through Integrated Neoproterozoic Drilling – The Ediacaran-Cambrian Transition’ (GRIND-ECT). Two drilling campaigns conducted by GRIND-ECT established a core network of correlative ECT strata, with the aim of reconstructing a highly resolved and temporally constrained stratigraphic, palaeontological and geochemical database.

Reliable information on past climates, diagenesis, and hydrogeology is crucial for understanding the Earth system. Sedimentary and authigenic carbonates and silicates provide primary archives of past geological conditions. Specifically, quantitative proxy data from both terrestrial and marine environments form the foundation of much of our knowledge about Earth’s history. Over the past two decades, the development of “next-generation” stable isotope paleoclimate proxies, such as clumped isotopes (∆₄₇ and ∆₄₈) and triple oxygen isotopes (δ¹⁸O and ∆’¹⁷O), has led to significant breakthroughs. Notably, these methods, have expanded traditional paleoclimate reconstructions by providing previously unattainable information on water chemistry, kinetic processes, vital effects, and diagenesis, and hydrogeochemical processes.

This session invites contributions that highlight how these new approaches enrich our understanding of Earth’s history. We particularly welcome applications of clumped and triple oxygen isotope proxies from Archean to Cenozoic sediments. Research topics may further include advances in methodology, new insights into the mechanistic basis of these tracers, and proxy–model comparisons.

The evolution of complex life on Earth and the stabilization of its biosphere have been fundamentally influenced by interactions between biological evolution, climate regulation, and redox conditions. This session aims to integrate deep-time climate modeling with geochemical datasets to explore how these factors contributed to planetary habitability.

Redox conditions, such as nutrient and oxygen availability, are fundamentally linked to the persistence and diversification of complex life over geologic time. The increasing oxygenation of deep ocean, shallow-marine, and terrestrial environments enabled the expansion of larger, more active, and ecologically differentiated biota. Geochemical proxies provide key insights into the redox evolution of Earth's oceans. When integrated with deep-time climate models, these datasets illuminate the role of stabilizing feedbacks in regulating redox structure and climate, including processes such as enhanced silicate weathering, reverse weathering, biological pump efficiency, and ocean acidification. We invite abstracts that integrate various lines of evidence from geochemical data and climate models to enhance our understanding of the coevolution of life and environment. We are particularly interested in elucidating the roles of geochemical and geobiological processes in regulating redox conditions during significant transitions, including - but not limited to - major biodiversification and extinction events, and seek to explore how various environmental controls influence the development and trajectory of life and habitability in the geologic record.

Well-preserved sedimentary successions are critical for our understanding of the long-term evolution of Earth’s surface environments and habitats for life. This session explores the dynamic interplay of biological, chemical and geological processes recorded in sedimentary archives from the early Archean to the late Proterozoic, and their implications for Earth’s evolving habitability. We invite contributions that focus on microbially-driven biogeochemical and mineral processes on the early Earth, as well as geochemical and sedimentological studies of early surface environments from drill core and outcrop investigations. In addition, we welcome contributions that cover the co-evolution of Earth and life during the Precambrian, for example from times with major geobiological changes such as the onset of plate tectonics and rise of atmospheric oxygen, to the mid-Proterozoic period of apparent long-lasting environmental stability. The session aims to integrate perspectives from geological, sedimentological and geochemical studies on the Precambrian rock record and potential modern analogues, as well as laboratory experiments, theoretical calculations and model simulations to provide a holistic view of Precambrian Earth-life co-evolution.

Understanding the intertwined evolution of Earth’s chemical and biological systems is crucial for uncovering the forces that have shaped life on our planet. Throughout geological history, biological and geochemical processes have interacted in complex and dynamic ways. This long-term interaction, however, has been marked by significant disruptions, such as mass extinctions and other major episodes of climate and environmental perturbations, that occurred during the Phanerozoic. Chemostratigraphy, including isotope stratigraphy, stands out as a robust method for unraveling the complex processes that have shaped Earth’s evolution, global changes, and their interplay with the evolution of life. We invite contributions addressing different time scales and stratigraphic resolutions, from decades to millions of years, which utilize a wide range of geochemical tools to develop a comprehensive understanding of how life, climate and environments have co-evolved during the Phanerozoic.

Global-scale geochemical processes on Earth provided the crucial ingredients for life, enabling prebiotic chemistry, the emergence of the first biomolecules and cells, and the evolution of multicellularity. Unraveling the nature, scale, and timing of these complex processes will advance our understanding of the co-evolution of life and Earth’s environment while leveraging Earth as an exoplanet for studies of habitability on other worlds. To this end, we invite submissions that use modeling and experimental methods to explore prebiotic geochemistry, mineral-organic interactions, nutrient cycling, planetary surface-interior processes, and planetary atmospheres as they pertain to the emergence and survival of life on Earth and Earth-like exoplanets. We also invite contributions on the environmental conditions necessary for the origin and persistence of the first structural/informational biomolecules and the formation of microenvironments conducive to early biochemical processes.

Ocean chemistry is integral to both short-term and long-term carbon cycles, influencing processes like alkalinity input, carbonate mineral saturation, and the biological pump that transfers carbon from the surface to the deep ocean. Despite their importance, large uncertainties remain in quantifying the sources and sinks of elements and isotopes in the ocean.

Elemental and isotopic concentrations are controlled by sources like riverine input from weathering, and removal processes such as precipitation, scavenging, and sediment adsorption. However, overlooked mechanisms—such as hydrothermal reactions, sediment interactions, coastal aquifers, and submarine groundwater discharge—can also significantly impact elemental and isotopic budgets.

Isotope systems like Sr, Nd, S, C, and N are widely used in paleoclimate studies, while emerging proxies like Mg, Ca, Li, and U show promise. Understanding the sources and sinks of these isotope systems is crucial for interpreting environmental changes in Earth's history and assessing global shifts.

We invite submissions that explore the ocean carbon cycle and its elemental and isotope budgets, particularly those focusing on overlooked processes. Contributions that include modeling global changes and their impact on the ocean and climate, both past and present, are especially encouraged.

Enhanced rock weathering (ERW) is a climate change mitigation strategy that accelerates the natural process of rock weathering to remove CO₂ from the atmosphere. It is emerging as one of the most promising and scalable negative emission technologies. While theoretically capable of sequestering gigatons of CO₂, significant scientific advancements are still required to resolve nano- to global-scale uncertainties related to variable dissolution and mineralization rates, climatic and soil regimes, chemo-mechanical processes, hydrology, and microbial processes. We invite contributions that explore ERW across diverse temporal, geologic, climatic, and topographic settings, and its co-benefits and adverse impacts on soil health, plant growth, and river, groundwater, and ocean systems.

We welcome topics leveraging mineralogical, geochemical, hydrologic, or radiogenic and stable isotopic tools to trace weathering processes and biogeochemical cycling, as well as numerical techniques. The session will also address broader challenges of CO₂ removal via ERW such as their integration with agricultural practices, scalability, and environmental impacts. We encourage research on the scientific principles underlying these technologies, including laboratory, field, and modeling studies that examine weathering and carbonation kinetics, isotopic tracers, and the implications of weathering on biogeochemical cycles.

Additionally, contributions that consider the socioeconomic and policy aspects of ERW deployment, such as measurement, reporting, verification, costs, and public acceptance, are welcomed. By combining perspectives across disciplines and scales, this session will foster a comprehensive understanding of ERW and its path towards large-scale implementation as a negative emission technology.

Natural organic matter (NOM) in aquatic and terrestrial ecosystems constitutes an integral part of the global carbon cycle and drives many biogeochemical processes. Physicochemical properties of NOM such as heterogeneity and polyfunctionality pose an additional layer of complexity in deciphering the role of NOM across spatial and temporal scales. Additionally, association of NOM with redox-sensitive elements such as iron, sulfur, nitrogen, or manganese can further influence speciation, mineral transformation, greenhouse gas emissions, microbial metabolism and nutrient bioavailability. Therefore, in order to decipher the ultimate role NOM plays in biogeochemical processes, it is essential to elucidate its molecular composition, and its pathways of transformation and decomposition.

This session aims to advance our current understanding of NOM dynamics in aquatic and terrestrial environments, including terrestrial-aquatic interfaces ranging from soil, sediments, wetlands to the seafloor. We invite contributions focusing on the role of NOM in 1) nutrient and contaminant cycling; 2) mineral transformations; 3) greenhouse gas emissions; and 4) microbial metabolism. Abstracts that examine these topics in the context of climate change are particularly welcome. Laboratory- or field-based experimental studies as well as theoretical modelling studies, and novel methodological insights that improve our current mechanistic understanding of the kinetics and pathways of NOM decomposition and transformation are encouraged for submission.

Biogeochemical transfer, migration and cycling of potentially toxic elements in earth surface is a complex process, which is influenced by both different anthropogenic activities and natural weathering effects. This session focuses on the topics that investigate elemental and isotopic fluxes of potentially toxic elements in the surface and/or deeper Earth processes within the Earth's Critical Zone and across the land-ocean interface. The session also welcome the topics on identification and tracking of the sources and the key processes of the potentially toxic elements and their potential links with climate change by using metal isotopes, multivariate analysis, and modelling frameworks.

As the climate continues to warm at an unprecedented rate, polar terrestrial ecosystems are becoming increasingly susceptible to abrupt and often irreversible changes. These shifts have profound implications for global biogeochemical cycles, influencing not just local environments, but also ecosystems far beyond the poles. It is evident that critical thaw-driven processes, such as glacial melting and permafrost thaw, play a pivotal role in this transformation. These processes lead to significant alterations in carbon, nutrient and elemental fluxes through various pathways, including runoff, leaching and sediment transport. Understanding these dynamics is vital, as export of bio-essential elements from polar ecosystems can have cascading effects on marine environments and global climate patterns. This session brings together researchers investigating the biogeochemical cycling within polar terrestrial ecosystems and resulting nutrient fluxes through river catchments and into marine environments.

We invite contributions from experimental, field-based, and modelling studies that address the following research themes: (i) investigating and quantifying carbon, nutrient and trace element delivery to Arctic and Antarctic oceans; (ii) examining the mechanisms and pathways of biogeochemical transformations that occur as these elements transition from terrestrial to aquatic systems; (iii) predicting and simulating changes in polar terrestrial-aquatic fluxes in the context of a rapidly changing climate. Furthermore, we encourage submissions that employ a diverse range of techniques and methods to investigate these biogeochemical processes at varying scales, from molecular interactions to global impacts. Ultimately, this session aims to enhance our understanding of dynamic biogeochemical processes in polar ecosystems and their significance in a warming world.

Minerals and microorganisms are ubiquitous inorganic and living constituents in a variety of ecological settings including soils, sediments and aquatic environments. Interactions between minerals and microbes govern a series of physical, chemical and biological processes, including soil and sediment aggregate formation, nutrient and contaminant availability and mobility, and organic carbon degradation, preservation and emission of green-house gases. Mineral-microbe interactions can also be integral to microbial community structure and function. This session aims to understand the interactions between minerals and microorganisms at the molecular level and nano to sub-nano scales, and how these interactions affect soil and sediment aggregate formation, elemental behavior, and particularly the accumulation of organic carbon at the mineral-microbe interface. We especially welcome studies that utilize advanced analytical techniques, including but not limited to synchrotron imaging and spectroscopy, m-CT, electron microscopy, atomic force microscopy, nanoscale secondary ion mass spectrometry (NanoSIMS), Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), and state-of-the-art molecular biology approaches.

Surficial geochemistry focuses on the distribution patterns, behaviour, processes, and reactions involving elements and isotopes in various spheres of the Earth's surface over diverse time and spatial scales. These processes are intimately linked to energy and mass transfers between the lithosphere, pedosphere, hydrosphere, atmosphere, and biosphere, and play an essential role in governing the sustainability of ecosystems and human society. However, there are many challenges in reliably reconstructing surficial geochemical processes, leading to controversies in how these mechanisms operate, presenting major challenges for meeting the UN Sustainable Development Goals. In order to promote a deeper understanding of the critical zone, this session focuses on exploring the latest research progress related to surficial geochemistry. We particularly encourage submissions involving traditional and non-traditional geochemical indicators, as well as solving scientific problems of the Earth's surface system over different temporal and spatial scales through a range of methods, including experiments, field observations, models, and machine learning. By bringing together research on a broad range of topics in surficial geochemistry, we aim to promote the frontiers of this field and to strengthen connections within and between disciplines.

This section aims to explore the intricate links between the redox states of Earth's atmosphere and oceans during the Precambrian eon and the evolution of life. The Precambrian, encompassing nearly 90% of Earth's history, witnessed significant transformations in both atmospheric and oceanic conditions that paved the way for biological innovation. We encourage submissions that investigate key events such as the Great Oxidation Event and the Neoproterozoic Oxygenation, along with the intermittent oxygenation periods. Additionally, we welcome submissions focused on understanding the mechanisms that triggered Earth's surface oxygenation, such as changes in surface weathering, perturbations in marine productivity, as well as Earth system modeling studies. The goal is to bring researchers together to develop a holistic view of how evolving redox conditions influenced the diversification and complexity of early life forms.

 The formation of the modern Asian topography, which was intricately tied to the emergence of contemporary land-sea distributions and landscape configurations, represents one of the most pivotal global geological events of the Cenozoic era, from 66 million years ago to the present day. In particular, the uplift of the Tibetan Plateau and the emergence of islands in Southeast Asia have influenced the evolution of the Asian environment, but also potentially played a crucial role in shaping Cenozoic climate patterns. In recent times, large-scale, multidisciplinary scientific investigations, employing cutting-edge technologies and innovative methodologies across both terrestrial and marine environments, have provided significant new insights. To gain a profound understanding of the historical evolution of the Asian topography and its underlying mechanisms, as well as how these processes have driven regional and even global climate changes, it is imperative to conduct a comprehensive comparative analysis of both terrestrial and marine records. This session aims to foster research that enhances our grasp of how, where, and when Asian topographic changes occurred, as well as their impacts on regional geomorphology, environmental change, weathering, erosion, and both regional and global climate. We particularly welcome contributions that emphasize comparative land-sea research.

The growing application of stable isotopes in environmental studies emphasizes their value in unravelling the processes that govern transformations and transfers of nutrients, contaminants and/or major elements, as well as their interactions at the rock-soil-atmosphere-biosphere interface. The use of metal stable isotopes, in particular, has proven its potential in revealing anthropogenic impacts, tracing the fluxes of elements in soils and sediments, and identifying the mechanisms and pathways of element translocation at the soil-plant interface.

However, the increasing use of stable isotopes technique has also exposed certain limitations, bringing new challenges while opening up opportunities for combining this tool with other cutting-edge techniques. Combining stable isotopes with methods such as spectroscopy, imaging, modeling, etc. can provide a more holistic view of complex geochemical, physico-chemical, and biological processes.

This session seeks multidisciplinary studies that showcase the complementarity of stable isotopes with other analytical approaches to push the boundaries of environmental research. We welcome abstracts from field investigations and in-lab experiments that explore the complex processes governing the behavior and the fate of nutrients, contaminants and/or major elements in the Critical Zone. Contributions that bridge stable isotopes with other different analytical methods with the aim to unravel the dynamics of metals and their bearing phases in natural and anthropogenic systems are particularly encouraged.

Continental margins host the global land-ocean interface where  strong boundary exchange and complex geochemical cycling take place. Significant differences in geological and oceanographic settings of continental margins worldwide mediate the complex propagation of terrestrial weathering signals from land to sea, while diverse marine weathering processes including reverse weathering in continental margin sediments further complicate the cycling of carbon and other key elements across various interfaces. The understanding of how natural and anthropogenic factors regulate the elemental cycling in continental margins across various temporal and spatial scales is thus of great significance for the study of weathering-climate links and feedbacks, and also for maintaining a sustainable and healthy oceanic environment in the future. We encourage holistic and comparative studies on various weathering processes and records of continental-margin critical zones that will provide better constraints on the flux and transformation of terrestrial matter from various sources to burial in continental margin sinks. Innovative and integrated approaches including in-situ observations, novel isotopic tracing and modelling that can advance the interdisciplinary studies of geochemical cycling in continental margins are particularly welcome.

The evolving field of non-traditional stable isotopes offers groundbreaking opportunities for reconstructing past oceanographic and climatic conditions with increased accuracy and detail. Recent advancements in analytical techniques, such as high-precision mass spectrometry, have enabled more accurate measurements of isotope ratios, while the application of these proxies in ancient time depends on the building of paleo-archives. Carbonate minerals can offer profound insights into the reconstruction of ancient climate since they record the ambient environments during their precipitation. Nevertheless, large efforts have been made in interpreting their geochemical compositions, in order to ensure robust proxy reconstructions. This session will focus on recent developments in the application of metal stable isotopes (B, Ba, Ca, Cd, Ce, etc.) and clumped isotopes in carbonate sediments and rocks, with particular emphasis on mollusk shells, foraminifera, corals, brachiopods, and other materials. We invite contributions that highlight breakthroughs in analytical techniques, integration of multiple isotopic proxies, biomineralization and early diagenesis processes that show significant influence on isotopic signatures, and modeling approaches that advance our understanding of isotopic signatures preserved in carbonate archives. We aim to bring together researchers exploring innovative uses of these geochemical tools to reconstruct past climate change and biogeochemical cycles. Participants are also encouraged to present their latest findings and methodological advancements in lab experiments of synthetic carbonates and early diagenetic processes of natural carbonate sediments. This session seeks to enhance our understanding of the geochemical processes recorded in carbonate archives, contributing to broader insights into Earth's climatic and environmental evolution.

River surfaces around the world release large amounts of carbon dioxide (CO₂) and methane (CH₄). These leaks of carbon reflect a suit of biogeochemical processes that produce the greenhouse gases in Earth’s critical zone, from ecosystem productivity to chemical weathering of rock derived minerals and phases (silicate minerals, carbonate minerals, sulfides, rock organic matter). A set of hydrological processes then govern the delivery of CO₂ and CH₄ to streams and rivers, while turbulent river flow can enhance their release. While we have a good understanding of the global magnitude of river CO₂ and CH₄ release, we still lack information on how these fluxes might change. Land use change, combined with rising temperatures and the changing hydrological cycle, are likely to have impacted these fluxes in the present day, and the magnitude of expected change is difficult to assess. In parallel, some carbon cycle management approaches (e.g. enhanced rock weathering) rely on streams and rivers to carry dissolved products, which could impact their greenhouse gas release. This session calls for work seeking to address this challenge, including: novel measurements of CO_2, CH₄ and N₂O fluxes in streams and rivers; from tropical to Arctic rivers, and from urban to non-urban; geochemical methods to track source and process (e.g. stable isotopes, radiocarbon, dissolved river chemistry); new approaches to flux upscaling; hydrological approaches to track gas transfer and export. We welcome field based studies, experimental approaches, in addition to data-driven, geospatial and numerical modelling techniques.

The detection of more than 5,500 exoplanets has expanded our need to understand climatic impacts of planetary characteristics and surface processes from just Earth to other worlds as well. Earth climate can be used as an analog for studying exoplanet climate, and many models explore both Earth and exoplanet climate to learn more about how differing planetary, atmospheric and ocean chemistry as well as surface processes (such as volcanism and silicate weathering) may influence long-term habitability. New advancements in exoplanet observations aim to constrain the atmospheric chemistry of more terrestrial exoplanets within the habitable zone in the near future. A main objective of this theme is complex planetary habitability, determining the necessary conditions for a climate where life can develop in preparation of future observations. Some key questions regarding exoplanetary climate and its impact on habitability include: How do interior and surface conditions of a planet impact its atmospheric properties? What are the effects of orbital parameters and long-term stellar variability on planetary climate and the development of Earth-like life?

In this session, we invite Earth and exoplanetary scientists specializing in a wide variety of modeling and physical science disciplines to explore planetary climates and the long-term habitability of terrestrial planets. We encourage interdisciplinary discussion and collaboration between fields to investigate these questions and guide future studies. Submissions from early career researchers are particularly encouraged.

Field and laboratory-scale studies have demonstrated a strong influence of mineral-organic associations on the transformation, trapping, and stabilization of soil organic compounds including fresh inputs of biomolecules from plant roots and microorganisms, biopolymers from plant matter, remnants of natural organic matter, and organic contaminants. The details of these associations and their subsequent impact on the fate of organic compounds in soils, however, remain incompletely understood. In the last decade, new insights into these associations have become increasingly accessible due to advances in a range of molecular-scale experiments and computational techniques (X-ray diffraction, infrared spectroscopy, nuclear magnetic resonance, synchrotron-based X-ray methods, mass spectrometry approaches, molecular dynamics simulations, quantum-level computation). In this session, we welcome oral and poster presentations highlighting applications of these techniques to gain new fundamental insights into catalysis of organic transformation at mineral interfaces, selective binding of organic compounds from organic matter, physical protection in clay interlayers and other mineral nanopores, formation of supra-molecular assemblages at organo-mineral interfaces, feedbacks between organic-mineral associations and wettability, and adsorption or transformation of organic contaminants.

Carbon dioxide removal (CDR) is recognized as a necessary component of society’s path toward achieving climate goals, with global scenarios that meet the objectives pursued by the Paris Agreement requiring several gigatons annually of CDR by mid-century in addition to emissions reductions. In order to assure that CDR approaches lead to meaningful climate impact, their net carbon removal as well as the uncertainties around carbon fluxes must be quantified. Additionally, to assess the potential of different CDR pathways, their underlying biogeochemical mechanisms must be well constrained, including any potential kinetic or thermodynamic limitations, biogeochemical feedbacks, as well as any impacts that may negatively impact CO2 removal fluxes or cause ecosystem change that increase CDR uncertainty.

Geochemical tools, both analytical and numerical, which have been developed for understanding natural geochemical processes, can be leveraged for quantifying carbon fluxes associated with CDR. We invite contributions that focus on 1) Understanding processes, fluxes, and biogeochemical feedbacks that constrain the carbon impact of durable CDR approaches in the ocean and on land; 2) Quantifying potential loss terms associated with CDR; 3) Using natural analogues to model the potential scale of CDR pathways; 4) Developing tools that can aid in Measurement, Reporting and Verification (MRV) to quantify and demonstrate the carbon impact of CDR projects; and 5) Developing integration of data and modeling approaches used for CDR.

Weathering processes in river basins have gained global attention due to their association with long term climate and geochemical mass budget of the open ocean. The silicate weathering of rocks play a crucial role in modulating the global climate over a million-year timescale through the sequestration of atmospheric carbon dioxide in the geological rock record. Moreover, the geochemical mobilization of chemical elements to river and groundwater has significant impact on human health, other aquatic biota as well as abiotic processes including ocean acidification status. Therefore, it is pertinent to understand the weathering processes in global river basins, explore their controlling factors over the Earth’s critical zone, and fingerprint the delivery pathways of their products to oceans. This session encourages papers focusing on rivers and groundwater as transporting agents of weathered materials from the terrestrial environment to nearby oceans as well as the geochemical abundance of water, suspended particulate matter and bedload sediments in
global river basins. The papers addressing the challenges faced in understanding of weathering processes during the Anthropocene will also enrich the session discussion.

Microorganisms are directly responsible for driving biogeochemical cycles. Recent advances in analytical and isotopic chemistry characterize elemental cycling in an unprecedented detail, and progress in molecular biology now allow us to routinely characterize the microbial communities and their metabolic activities. The synergistic potential of combining those large datasets in marine biogeochemistry and geomicrobiology is clear, but major challenges remain in interpreting these datasets. To better exploit the full information from coupled molecular biology and biogeochemical data innovative approaches for leveraging ecological theory and evidence are required, including coupled process-based models and data-driven machine learning methods.

In this session, we aim to attract interdisciplinary studies across aquatic and terrestrial environments that combine elemental and isotopic geochemistry (e.g., aquatic geochemistry, stable isotope probing, lipidomics, etc.) and microbial ecology (e.g., metagenomics, metatranscriptomics, etc.) to facilitate our understanding of the functioning and prevalence of biogeochemical processes. We welcome studies providing innovative tools or a novel combination of already existing techniques to quantify nutrient and carbon cycling, energy turnover, contaminant degradation, and greenhouse gas emissions. We particularly also encourage submissions on novel ecological theory and model concepts that allow for model integration with lab- or field-based data across spatial and temporal scales.

Minerals have been shown to play a direct role in protecting and preserving biomolecules including DNA, RNA, proteins, and nucleotides in terrestrial and marine systems. Mineral surfaces can catalyze (e.g., oligomerization of nucleic acids in early earth systems) or stabilize biomolecules (e.g., preservation of ancient and environmental DNA) in natural environments. For example, the recent successful recovery of ancient DNA directly from sediments has shed new light on human history and ancient ecosystems. Though, method development over last decades has facilitated recovery of these molecules to track evolutionary processes and to reconstruct past environments, there are still challenges regarding the extraction of sedimentary DNA, particularly, in absence of fossilized bones. Additionally, the exact mechanisms that contribute to long-term preservation of biomolecules in the environment remain elusive. A deeper understanding of the mechanisms governing mineral-biomolecule interactions is essential to advance our knowledge on the preservation of ancient, environmental, and sedimentary DNA, the transformation and stability of biosignatures in terrestrial and extraterrestrial environments, the fate of viral DNA/RNA in wastewater-based epidemiology tracking, and the role of minerals in the origin of life and earth’s history.

We invite experimental and theoretical studies that improve our understanding of the behaviour, function, and fate of biomolecules at mineral surfaces with applications across disciplines including but not limited to archaeology, astrobiology, biogeochemistry, environmental forensics, horizontal gene transfer, wastewater surveillance and origin of life.

This session will explore the interconnected processes of organic matter (OM) production, transformation, and long-term storage that underpin ecosystem balance and influence global energy distribution and climate. Primary producers convert solar energy to OM, which then begins its journey through food webs and microbial loops and on to environmental transformation and geological burial. Combined biological and abiotic mechanisms govern the reactivity and preservation of OM in aquatic systems, soils, and sediments, and thereby the partitioning of energy among major carbon reservoirs, including atmospheric CO₂. Improved understanding of the factors that control these processes is required to inform global carbon cycle models, environmental management, and carbon sequestration.

Advancements in isotope methodologies, including those that target signals alternative to those recorded in carbon, have facilitated identification of novel pathways of OM transformation and more precise quantification of carbon fluxes. These techniques are now expanding our ability to track OM through complex nutrient and energy pathways, from surface and shallow ecosystems to the deep biosphere. Key to these processes are environmental conditions, such as redox changes, pH, temperature, and organo-mineral interactions that shield OM from microbial and enzymatic degradation.

We kindly invite all researchers and attendees who contribute to this integration of insights from experimental, observational, and modeling approaches to deepen our understanding of OM cycling.

The surface S cycle is central to the evolution of Earth’s redox state, climate, and biosphere. It is governed by a dynamic interplay between atmospheric, lithospheric, and biogeochemical processes and is strongly linked to other elemental (e.g., Fe, C, and O) and trace metal (e.g., Cu, Ba) cycles through complex redox processes. Biogeochemical S cycling, including microbial sulfate reduction, disproportionation, oxidative S cycling, and chemical weathering of S minerals, occurs in diverse sedimentary and hydrothermal environments. The resulting minerals and biomass are critical archives for paleoenvironmental change (i.e., proxies) and the evolution of life (i.e., biosignatures). These archives have been examined for decades using techniques from mineralogy, stable isotope geochemistry, and environmental microbiology. Still, many questions remain about interpreting geochemical fingerprints of microbial S cycling in modern and ancient environments. By bringing together a diverse group of speakers and attendees, this session aims to advance our understanding and quantification of processes operating within Earth’s S cycle in deep time and today. We invite studies from geochemically diverse environments, including marine and terrestrial sediments, hydrothermal vents, and the deep subsurface, from modern to ancient Earth. We particularly encourage submissions that use novel analytical tools such as minor isotope (³³S, ³⁶S, ¹⁷O) geochemistry, biomarkers, enzymology, and ‘omics’ studies. Novel experimental approaches are welcome, as are computational studies.

Extreme environments play a crucial role in Earth's biogeochemical cycles through processes including mineral precipitation, nutrient remineralization, the storage and release of greenhouse gases, which impact the cycling of key elements and climate regulation. These unique environments not only contribute to global cycles but are also potential terrestrial analogs of other planetary bodies such as Mars or the icy moons Enceladus and Europa. Studying these analog sites makes it possible to infer biogeochemical processes happening beyond Earth’s boundaries and ultimately address questions related to the environmental limits of life, the habitability of planetary bodies in the solar system or beyond, and the preservation and detection of relevant biosignatures in the ongoing search for life.

This session will feature presentations covering all aspects of chemical, physical, biological, and geological processes, the interactions of these processes in extreme environments, and how to leverage improved insights of extreme environments to better understand global biogeochemical cycles on Earth and other planetary bodies. We welcome work on the cryosphere, anoxic environments, deserts, hydrothermal vents, and hyperalkaline springs among others. We invite contributions that examine the chemical weathering of minerals, the cycling of nutrients and contaminants, isotopic ratios, microbe-mineral interactions, biofilms, organic substrates and metabolites, extremophiles, and the use of cutting-edge technologies to detect and analyze biosignatures. By synthesizing findings across different geographic regions and time scales, this session aims to enhance our understanding of the implications of extreme environments for the future of our planet's biogeochemical cycles and their applications to other planetary bodies.

Micro and nanoscale imaging and spectroscopic analysis are critical for studying complex biogeochemical processes in fields of aquatic, terrestrial, and planetary sciences. Spatiotemporally sensitive measurements of microbial community dynamics, organo/microbe -mineral interfaces, and nanoscale mineral weathering processes in heterogeneous systems enable the decoupling of distinct biogeochemical reactions, allowing the investigation of relevant mechanisms.

This session aims to advance our knowledge of using innovative imaging and spectroscopic techniques including confocal Raman microscopy, scanning probe microscopy, light-sheet fluorescence microscopy and synchrotron-based techniques (e.g., Scanning Transmission X-ray Microscopy (STXM), X-ray Fluorescence Microprobe (XFM), ptychography, X-ray Absorption Near Edge Structure (XANES)) to investigate biogeochemical reactions. We welcome contributions that: (1) utilize one or multiple imaging and spectroscopic techniques to study biogeochemical reactions; (2) employ novel experimental tools (e.g., microfluidics, correlative microscopy, in situ 3D imaging under cryo- or hydrated conditions, and bioreporters) to investigate microbial interactions; and (3) apply conventional and customized data analysis tools to interpret imaging results from across various analytical techniques.

This session is supported by the “Synchrotron Earth and Environmental Science” (SEES) program funded by the National Science Foundation in the U.S., which aims to advance research and techniques that utilize synchrotron radiation facilities to Earth and Environmental studies.

This session focuses on the role of biomineralization in Earth’s geochemical cycles, with minerals formed by organisms acting as crucial proxies for reconstructing paleo-environmental conditions and understanding Earth system processes. Biominerals, particularly primary carbonates such as dolomite, along with oxyhydroxides, sulfides, and phosphates, serve as environmental archives, at times preserving signatures that can reveal insights into past climates, evolving atmospheric conditions, and the dynamics of the Earth System. We welcome studies on the formation and transformation of biominerals, as well as the complex interactions between biotic and abiotic factors that influence mineral stability and possible preservation from diagenetic overprinting. Contributions from diverse integrated fields—such as geochemistry, geomicrobiology, and sedimentology—are encouraged to deepen insights into mineral-driven cycles of carbon, oxygen, sulfur, silica, iron, and other key elements across geological time.

This session focuses on the critical role of coastal sediments and wetlands as interfaces in global biogeochemical cycles, shaping nutrient dynamics, carbon sequestration, and pollutant mobility across the land-ocean continuum. Coastal systems, including sediments and wetlands, function as transition zones that mediate element exchanges through complex interactions of biotic and abiotic processes, such as early diagenesis, redox reactions, and hydrological mixing influenced by tidal and riverine forces. The sensitivity of these ecosystems to human impacts, such as urbanization, pollution, deforestation, and climate change, including sea level rise and flooding, amplifies their dynamic nature and necessitates innovative research approaches. Traditional models often fail to capture the high temporal and spatial variability of these systems; thus, this session invites contributions that highlight advancements in high-resolution methodologies such as isotope geochemistry, hyperspectral imaging, and reactive transport modeling. We seek interdisciplinary research that explores the micro- to macro-scale interactions at particle-water-biota interfaces, with a focus on nutrient cycling, trace metal mobility, and redox-driven element transformations. By bringing together studies in geomicrobiology, biogeochemistry, sedimentology, and environmental physics, this session will encourage the integration of fieldwork, laboratory experiments, and computational modeling to advance our understanding of coastal resilience. Discussions will address the broader implications of these coastal processes for climate adaptation, environmental health, and ecosystem sustainability.

Biogeochemical cycles have changed throughout Earth’s history, driven by the evolution of living organisms and environmental conditions. These changes are reflected in major elements, including carbon, nitrogen, phosphorus, as well as trace elements, such as molybdenum, iron and nickel. Significant variations in speciation and concentrations occurred across Earth’s surficial reservoirs. Remarkable progress has been made in recent decades in deciphering trends and trajectories in the evolution of biogeochemical cycling alongside changes in geochemical parameters such as pO₂, pH or alkalinity. Studies of the geological record during extreme states such as the Great Oxidation Event, Snowball Earth intervals, hothouse climates, and modern environments influenced by anthropogenic stressors (e.g. excess P delivery) are critical for exploring the intricate geobiological dynamics (rates, thresholds and feedbacks) and its effects on Earth's surface temperature, nutrient availability and ecosystems. This session aims to deepen our understanding of the co-evolution of biogeochemical cycling and nutrient dynamics on Earth. We invite submissions of integrated geochemical datasets and/or evolutionary models for ancient, modern, and engineered ecosystems, spanning from molecular processes to sedimentary basins and back to the primitive Earth’s environment. Topics such as enzymatic evolution, Earth System modelling, biomineralization, and astrobiology are especially welcome. Additionally, we encourage contributions on the applications, potentials, and limitations of novel isotopic, spectroscopic, and microscopic analytical methods within biogeochemical cycles.

Hydrothermal systems, from sunlit shallows to the dark ocean depths, create some of Earth's most dynamic environments by linking the geosphere to the biosphere. Chemical energy produced during water-rock interactions supports diverse microbial communities and drives unique ecosystems that transition from photosynthetic to chemosynthetic life. Changes in energy sources coincide with depth in marine environments or with distance from the source in terrestrial hot springs. This intricate interplay extends into hydrothermal plumes, where relatively reduced hydrothermal fluids mix with oxidized seawater, creating extreme gradients in redox potential that power chemoautotrophic metabolisms. This session explores the evolution of hydrothermal systems across varying depths and distances, emphasizing the impact of geology, fluid chemistry, and redox conditions on microbial adaptation and ecosystem dynamics.

Key questions include: How do shifts in geology and fluid chemistry influence the energy landscape and habitability for microbial communities at different depths and distances? What role do these chemical energy supplies play in the evolution from photosynthetic to chemosynthetic life, and how do symbiotic relationships with microorganisms support higher organisms? Beyond Earth, can these processes inform our understanding of habitability on other ocean worlds, where water-rock interactions provide potential chemical energy sources?

We welcome contributions from scientists at all career stages, spanning disciplines including geochemistry, biogeochemistry, geomicrobiology, and related fields, using field studies, laboratory experiments, geochemical and microbial modeling, and molecular "omics." This interdisciplinary session aims to bridge our understanding of hydrothermal systems as an ecological and geochemical continuum, connecting Earth’s dynamic environments to the potential for life beyond.

As food security becomes a growing concern with increased human populations and the threat of global change, it is essential to understand the effects of both climatic change and land management strategies on biogeochemical cycling in agroecosystems and associated crop productivity. Climate change is projected to bring about fluctuating temperatures, high precipitation rates, increasing CO₂ levels and storm-water intrusion, which can decrease crop yields and nutritional quality. Land management strategies (e.g., fertilizer/pesticide application, crop selection, microbial inoculation, irrigation management) greatly influence biogeochemical cycles by altering soil properties, microbial communities, and plant processes. The primary aim of this session is to gather the scientific minds who are working on the interphase of soil-plant-microbes with special emphasis on climatic changes and different agronomic practices. This session welcomes contributions that address the effect of climate and land management on

1. Biogeochemical cycles of major nutrients (e.g., C, N, P, S), essential micronutrients (e.g., Fe, Se, Zn), or potential toxicants (e.g., As, Cd, Cr, Hg, Pb).
2. Molecular microbiome structure and response
3. Crop-microbial interactions

Studies from microscale to field scale fall in this scope. Fundamental/mechanistic/process-based studies are highly encouraged.

Mechanistic geochemical knowledge across a range of scales is often at the center of optimal design and implementation of strategies for soil and water remediation and resource recovery. Notable examples that have benefited from molecular-scale understanding of geochemical drivers include phytoremediation, soil amendments and chemical injections for contaminant stabilization. Advanced synchrotron-based X-ray characterization techniques, and particularly the use of multi-modal approaches, have revealed complex pathways of contaminant geochemical cycling with implications for bioavailability and ultimate cross-scale outcomes. This multidisciplinary session aims to showcase use-inspired research projects that rely on a detailed mechanistic understanding of underlying geochemical processes on small and large scales, with a particular emphasis on inorganic pollutant behavior (e.g., Pb, Cd, Hg, N, P, U, As) across a variety of environmental interfaces. We especifically encourage presentations that integrate molecular-scale data with macroscopic measurements to directly investigate metal(loid) and/or nutrient dynamics to inform solutions for remediation or resource recovery. We look forward to an inspiring session that includes presentations from early-career to senior scientists with diverse expertise to delve into key geochemical processes underpinning environmental solutions and how to collectively harness this knowledge.

Confined water plays a pivotal role in mediating geochemical processes across various natural systems, including minerals, soils, aerosols, and biologically active environments. These processes occur at critical interfaces and contribute to large-scale phenomena such as lithification, dissolution, and elemental cycling, all of which are particularly sensitive to environmental perturbations such as sea level rise and climate change. This session will focus on the unique physical and chemical properties of interfacially confined water, its mobility and reactivity, and its interactions with surrounding environments.

While we aim to explore novel experimental observations and theoretical predictions of confined water behavior at fine scales, we also welcome submissions that address the role of confined water, including that within aerosols, in influencing elemental transport, mineral stability, and reactive processes in response to global change and anthropogenic perturbation. By bridging fine-scale insights with large-scale geochemical phenomena, this session seeks to advance our understanding of how confined water shapes the Earth's dynamic systems facing the challenges of global change.

One of the main challenges of current research on nutrient and pollutant cycling in surface waters (lakes, rivers) and groundwater, and the functioning of the continental Ecosphere, lies in the development of approaches that integrate across element cycles and various scales from small catchments to large regional watersheds. The combination of chemical, isotopic and microbiological techniques has emerged as a very promising approach for gaining novel insights into the sources, processes and products that govern element cycling in lakes, rivers, the water-unstarurated zone, and groundwater in watersheds of various scales. This session will focus on the use of isotopic tools in combination with hydrologic, chemical and microbiological approaches in watersheds of various sizes to gain novel insights into:

• Nutrient (C, N, P, S, H) cycling and interactions of nutrient cycles.
  
  
• Identification of sources and tracing the fate of point source and non point source pollutants including emerging contaminants.
  
  
• Greenhouse gas emissions (N₂O, CH₄, etc.) to the atmosphere from aquatic systems, soils and the soil-plant interface.

We welcome innovative contributions on analytical developments, laboratory and mesocosm experiments, field studies at different scales, and modelling approaches.

Dynamic redox processes influence element cycling, electron transfer reactions, mineral transformation, release of greenhouse gases and degradation of organic matter (OM), exerting direct control over the behavior and fate of nutrients and contaminants in terrestrial systems. For example, minerals bearing redox-active elements (e.g., Fe, Mn, S) undergo dissolution and (re)precipitation processes that control the bioavailability of contaminants (As, Cr, Cd, Pb, Sb, Se,V, U,...) and nutrients (P, Cu, Zn...). These atomic scale processes at aqueous-mineral interfaces drive water and soil quality, but the kinetics of these reactions and their complexity and heterogeneity at molecular and field scale are still not fully understood.

We welcome contributions that improve our mechanistic understanding of (1) mineral transformations in redox-dynamic environments, (2) the fate and behavior of contaminants and nutrients in redox dynamic environments, (3) elemental cycling of redox sensitive elements in the terrestrial, aquatic, and coastal systems, (4) novel methodologies to characterize these processes in natural environments, and (5) modeling studies that consider redox processes and their impact on environmental systems.

Global changes, including climate variability, shifting land use, and other anthropogenic pressures, rapidly alter biogeochemical cycles, affecting the structure and function of terrestrial and aquatic ecosystems. Because catchments integrate terrestrial landscapes, freshwater systems, and coastal environments, they serve as sentinels of these global environmental changes. By capturing the cumulative influence of upstream drivers, catchments reveal the pathways, magnitude, and complexity of global change signals that ripple through entire ecological networks. Understanding these signatures, and how they emerge from the interplay of multiple drivers, is essential for revealing underlying mechanisms, forecasting future trajectories, and guiding informed management.

This session advances systematic research into how catchment biogeochemistry responds to global-scale drivers, as well as to acute disturbances. We welcome presentations that utilize observations, experiments, and modeling to generate, analyze, and interpret biogeochemical fluxes within watersheds and among their subsystems, with a specific emphasis on characterizing and predicting rapid ecosystem changes. Topics include, but are not limited to: 1) landscape processes influencing chemical loads; 2) biogeochemical fluxes at the groundwater–surface water interface; 3) innovative methods for gap-filling and modeling biogeochemical records; 4) trajectories of carbon, nutrients, metals, contaminants, and radiotracers; and 5) responses of catchment biogeochemical dynamics to climate change, land-use shifts, and episodic pollution events. We particularly encourage interdisciplinary and cross-system studies that use catchment biogeochemical signals to enhance our understanding and management of accelerating ecosystem transformations.

Many catchments worldwide are increasingly threatened by both natural and various anthropogenic stresses, such as changes in water resources management and climate change. These stresses reduce resilience and increase vulnerability to extreme events, making it crucial to understand the complex dynamics governing these natural systems. However, predicting the geochemical responses (e.g., major ions, trace elements, nutrients) of catchments to local and global changes is particularly challenging due to the heterogeneity of landscape features, non-linear geo-hydrological processes, surface-groundwater interactions, organized states far from equilibrium, and intricate biogeochemical cycles. To derive generalizable insights, it is essential to move beyond current understanding and employ new approaches to examine the sources of variability across multiple scales.

This session invites contributions that analyze catchments worldwide, highlight innovative methodologies, or explore their functional principles from a multidisciplinary perspective. Examples include:

• Applications of computational multivariate methods developed under the CoDA (Compositional Data Analysis) theory
• Studies involving trace elements (e.g., As, U, Pb, Hg) and nutrients (e.g., nitrate, phosphate, sulfate), which have health impacts from essential to toxic, depending on their concentration and speciation. To tackle exposure to toxic elements, it is important to understand larger scale trace elements mobility in and across reservoirs spanning from surface water, soils, vadose zone to groundwater.
• Contributions that integrate and upscale lab, field, modeling and statistical methods to the catchment scale.
• Investigations that explore the spatio-temporal variability of riverine media (e.g., river waters, stream sediments, suspended solids), with studies involving biological matrices, soil processes, and groundwater also welcomed.

Water is arguably the most vital geo-resource, but quantifying flow systems remains problematic. Gas, ionic, and particle tracers along with isotopic methods are essential for assessing dynamics and anthropogenic pressures in natural waters, such as streams, lakes, and oceans, as well as in groundwater. Recently, these methods have also been applied to pore waters in sediments and unconventional porous media, such as trees. These same methods are now successfully being applied in fracking experiments and geological CO₂ sequestration projects to geochemically track fluid evolution in the subsurface in real time.

As tracer data reflect the intrinsic physical, hydrogeochemical, and (micro) biological dynamics of water and fluid systems (e.g. turnover times), they provide a robust conceptual framework for developing accurate (numerical) models that simulate the evolution of water and other geo-fluids and the potential for geothermal energy production.

To bridge the gap from measurements to assessments, we invite contributions on novel technical developments in tracer analysis (e.g., ³⁹Ar and ⁸¹Kr determination, continuous gas monitoring, membrane-based ³H analysis), as well as on classical tracer applications. We also explicitly welcome innovative model applications that incorporate environmental tracer data to enhance predictions of water and fluid dynamics in terrestrial environments.

Contaminant releases with complex compositions into the environment can severely impact water and soil quality, posing an alarming environmental threat. The geochemical understanding of processes, environmental fate, and transport of these contaminants is essential for developing innovative and sustainable remediation strategies. Critical areas of study include contaminant mobility, toxicity, transport pathways, exposure risks, and environmental remediation. Traditional remediation techniques are often energy-intensive, costly, and inefficient, highlighting the need for sustainable alternatives. Emerging solutions such as natural attenuation, reactive mineral species, agro/bio-waste applications, and nanomaterials, including adsorbents, hold promise for addressing these challenges.

This session aims to explore the fate and transport of contaminants under varying geochemical conditions and showcase innovative remediation strategies for contaminated water and soils. We encourage research on physical, chemical, and biological treatment methods, contaminant characterization, and theoritical modeling focused on pollutant removal, waste reuse, resource recovery, and circular economy approaches. Submissions may cover, but are not limited to: 1) contaminant characterization in soils, water, and wastewater (industrial, agricultural, energy-derived) and associated toxicity, 2) geochemical changes in water and sediments at contaminated sites, 3) novel analytical, modeling, and experimental tools, 4) remediation strategies including mineralization, novel (nano)materials, and natural attenuation, and 5) lab and field-scale experiments investigating biological and geochemical responses to contaminants. Targeted contaminants include heavy metals, radionuclides, PFAS, PPCPs, NAPLs, VOCs, pesticides, textile dyes and fibers, and micro- and nanoplastics.

All aspects related to minerals as vectors of trace element and organics in environmental compartments are welcome in this session. We are particularly interested in an integrative approach spanning the entire journey from the source to the destination of the trace elements and organics, for example, from bedrock weathering to the global ocean, and from soil remediation to soil carbon storage. The session will explore the role of minerals as vehicles for the trace elements, in the crystal structure of the minerals or in the defects, including surfaces. Some aspects, such as sorption on solid surfaces, have been extensively studied over the years, while others, like the characterization of the minerals themselves, have been much less explored. Comparably little is known about the way the minerals incorporate trace elements and organics, retain, transport, and release them. We welcome contributions that address these issues and identify viable pathways for the solutions of the outstanding questions. The aim is to share techniques and approaches, from the laboratory to the field, to better understand the role of minerals. The session aims to bring together different disciplines and perspectives, from mineralogy to geochemistry and environmental chemistry. The session is open to any trace element and organics in a given system, with preference to technologically critical elements and potentially toxic elements, as well as organics.

The session will highlight advanced research on the transport and transformation of compounds in soils followed nor their translocation into plants. The combination of geochemical and isotopic techniques has permitted a deeper understanding of the mechanisms controlling the elementary transfer in the ecosystems, with implications for agricultural productivity, food safety, and environmental risk mitigation. Interdisciplinary in nature, this session will address the interface between soil geochemistry, plant biology, and microbial activity, focusing on nutrient and contaminant cycling. The contaminant mobility and bioavailability are primary of interest to adapt different (phyto) remediation approaches up-to-date approaches, techniques and models for deciphering and predicting the fate of nutrients and contaminants in the soil-plant system will be encouraged. In particular, isotopic investigations in the soil-plant systems and models integrating geochemical data will be considered. The session will also emphasise sustainable practices for nutrient and contaminant management, with the ultimate aim of promoting suitable agricultural, biotechnological, and environmental engineering practices.

Geochemical and microbial processes alter the distribution of emerging contaminants and affect their fate at sites of environmental releases and during movement in the subsurface and impacted water resources. A detailed understanding of these processes through field and associated laboratory studies is key to defining contaminant sources and exposure pathways, designing remediation approaches, and understanding potential human and ecological health effects.

In this session, we encourage studies that will help define the processes that control the distribution and fate of emerging contaminants from releases in the environment and during their movement through soil, sediment, and water resources. We encourage submissions related but not limited to 1) field studies that aim to identify the processes that control contaminant distribution, composition, and movement in soils, sediment, and impacted water resources, 2) mechanistic studies of the geochemical and microbial alterations of emerging contaminants and contaminant mixtures in environmental media, 3) studies that link contaminant geochemistry and distribution to understanding exposure pathways and human or ecological effects, 4) development of novel modelling and experimental tools applied to movement, fate, and effects of environmentally relevant contaminant concentrations, and 5) lab and field-scale experiments investigating geochemical and microbial processes controlling fate and effects of emerging contaminants. Environmental release areas of interest include spills, wastewater, and biosolids from municipal, industrial, agricultural, and energy-related sources. Targeted contaminants include PFAS, microplastics, 6PPD & 6PPD-quinone, pesticides, quaternary ammonium compounds, pharmaceuticals and personal care products, and complex contaminant mixtures.

In this session, we aim at exploring the relationships between the natural and disturbed geochemical composition of the Earth's surface and their consequences for human and ecosystem health. Geochemical factors dictate soil and sediment composition, thereby influencing water quality and plant, animal, and microbial life. Key processes—such as climate change, urbanization, and land-use changes—are intertwined with environmental issues like pollution from mineral resource extraction and novel anthropogenic materials. Epidemiological studies indicate potential causal links between altered geochemical environments and adverse health outcomes (affecting humans, animals, and environmental health). We welcome submissions that explore topics related to identifying sources of harmful substances, their bioavailability, exposure pathways, deposition and degradation, health impacts, and the implications for mitigation and policy. Contributions of interest include, but are not limited to, environmental toxicology associated with harmful elements, industrial toxic particulates, persistent organic pollutants, and emerging contaminants from human activities, such as electronic waste recycling and artisanal and small-scale gold mining. Additionally, we encourage contributions addressing the environmental impacts of PFAS, pharmaceuticals, or plastics, the effects and toxicity of metal mixtures, elemental speciation of toxic elements, and nanoparticle toxicology. Relevant studies may also explore environmental cycles, exposure pathways (e.g., soil-to-plant transfer), and population vulnerability, incorporating biomarker and biomonitoring approaches. Furthermore, we invite research on source apportionment through modelling or tracer studies to deepen our understanding of the impact of human activities, natural hazards, and climate change on geochemical systems and their consequent potential impacts on human well-being, especially vulnerable communities.

Plastic is an integral part of almost all the necessary goods of our modern lifestyle and one of our time's most demanded and produced materials. At the end of their use, used plastics form millions of tons of waste that are poorly managed. Currently, plastic has been found and accumulates everywhere on our planet in all environmental compartments including aquatic, atmospheric, and terrestrial systems and as a result, is dispersed across environmental compartments by atmospheric transport, and surface, subsurface and river runoff. Exposure to light, moisture, heat, biological activity, mechanical stress, and other factors causes plastics to fragment into smaller pieces, ranging in size from a few centimeters to the nanoscale. Small plastic particles such as microplastics (MPs) and nanoplastics (NPs) are bioavailable for a wide number of living organisms from zooplankton to mammals to plants, with potential negative consequences for the biosphere. Besides the negative impact related to the particles themselves, there is concern about plastics-associated chemicals including additives and pollutants adsorbed from the environment. The diversity of size, shape, and chemical composition makes it difficult to determine the behavior of this ubiquitous pollutant and its adverse effects on ecosystems and human health. In this session, we welcome studies that will help understand the occurrence, sources, fate, behavior and impact of plastics, MPs and NPs in the environment, including analytical developments, numerical modeling, field observations, experimental studies and discussions on policy frameworks relevant to the atmosphere, pedosphere, hydrosphere and biosphere.

Connections between human health and the environment have long been recognised and geochemical tools have been used to investigate these connections. The focus of this research has mostly been on contaminants and toxisity as well as nutrients and the quality of soil, air and water.
In more recent years, the direct application of geochemical techniques as diagnostic tools (biomarkers) for the detection and monitoring of human health and disease has been a rapidly expanding field of research.
Therefore, this session is intended bring together studies of the “natural” budget of elements and their isotopes in the human and mammal body as well as processes (e.g. disease, nutrition, injury) that lead to imbalances of that budget.

Topics can include (but are of course not limited to):

• Metallomics
• Nutritional processing
• Diagnosis/Detection of diseases and monitoring of disease progression
• Intervention/Therapy monitoring and evaluation
• Monitoring post-surgery health
• Understanding causes of disease and its progression

The cycling of trace metals in polar oceans is crucial for understanding biogeochemical processes and ecosystem health in these sensitive environments. Trace metals such as Fe, Zn, Ni, Mn, and Co are essential micronutrients that regulate phytoplankton productivity across vast regions of the global ocean, notably the Southern Ocean and Arctic, significantly impacting carbon cycling between ocean and atmosphere. In contrast, toxic elements such as Hg which is of special concern in Arctic, are posing potential environmental risks. Polar regions act as critical zones for ocean-atmosphere interactions, with trace metal inputs from sea ice, icebergs, weathering, melting permafrost, hydrothermal activity, continental shelf sediments, and atmospheric deposition altering primary production. Trace metal isotopes and other means such as rare earth element composition have revolutionized our ability to trace the sources, pathways, and biogeochemical processes of trace metals in the ocean. These tools allow us to distinguish external input and disentangle biogeochemical processes such as biological uptake, particle‐solution exchange, and remineralization, and provide insights into past ocean conditions.

However, the remoteness, extreme weather, and technical challenges in clean sampling and trace metal analysis hinder our understanding of their cycling in the rapidly changing polar oceans. Enhancing our knowledge of these understudied regions is critical, as polar seas and the cryosphere act as precursors for global changes in other ecosystems. To this end, this session invites research integrating isotopic, trace metal data, and biogeochemical models to explore sources, cycling, and biological responses, advancing predictions of polar ocean impacts on climate change.

To effectively limit the global temperature increase to below 1.5 °C, it is critical to reduce not only carbon dioxide, but also short-lived climate pollutants (SLCFs). These SLCFs can exert cooling or warming effects through interactions with radiation and clouds. In most cases, SLCPs are also air pollutants. Key SLCFs include atmospheric aerosols (such as black carbon, brown carbon, sulphate, nitrate, ammonium, and aeolian dust) and chemically reactive gases (including methane, nitrogen oxides, carbon monoxide, ozone, non-methane volatile organic compounds, sulphur dioxide, and ammonia). With recent breakthroughs in isotope geochemistry and atmospheric chemistry, our understanding of the fate of aerosols, methane, and other SLCFs has grown, revealing their intricate connections to both climate change and air quality.

This session spotlights the most recent breakthroughs in stable and radioactive isotope geochemical techniques, coupled with state-of-the-art experimental, field, and modeling approaches from various disciplines. We emphasize their essential role in unmasking the sources of SLCFs, unraveling complex atmospheric processes, decoding biogeochemical cycles, and assessing their effects on climate and air quality. We cordially invite researchers to contribute their insights on the sources, processes, mechanisms, and impacts of SLCPs. Our session will cover an extensive array of topics, encompassing method development, field observations, laboratory experiments, model simulations, and crucial discussions related to methane, aerosols, and other SLCFs. Through this session, we aim to foster a comprehensive understanding of SLCFs, thereby enabling more effective strategies for climate change mitigation and air pollution control.

The chemical composition of seawater—encompassing major and trace elements, isotopic compositions, alkalinity, redox conditions, pH, and salinity—has fluctuated significantly throughout Earth's history. These changes provide a unique and indispensable window into the complex interactions among Earth's spheres, including the evolution of biosphere habitability, shifts in atmospheric oxygen and carbon dioxide levels, the elemental and mineral composition of the lithosphere, and material cycling between Earth's internal and external layers. Understanding the long-term variations in seawater chemistry, the key drivers behind these changes, and their quantitative links to geological processes has greatly advanced our knowledge of Earth's surface system evolution and long-term habitability.

This session invites contributions focused on the evolution of seawater chemistry across various timescales, its implications for ocean habitability, and its interactions with Earth's diverse spheres. We encourage presentations that explore seawater chemistry evolution in the geological record and the mechanisms driving it, through the development and reevaluation of marine proxies and archives, experimental simulations, data integration, numerical modeling, and big data approaches, aiming to foster a comprehensive understanding of seawater chemistry evolution and key geological processes across Earth's spheres.

Oxygen is rapidly declining in the world’s oceans as climate change accelerates, and the extent of low-oxygen waters has increased as a consequence. In order to contextualize our present and make reasonable projections into the future, we must develop a better understanding of present forcing and past ocean oxygenation, the relationships between ocean oxygen and global climate, and the impacts of changing ocean oxygen on marine life, geochemical cycles and the blue economy. Geochemical tools and biogeochemical models have proven invaluable for enabling us to assess the present, to reach beyond modern observations and develop records of past ocean oxygenation and low-oxygen environments, and to project future deoxygenation trends and their impacts. This session invites submissions that advance an understanding of present, past and future ocean oxygenation with diverse approaches including measurements, modeling, proxy development and applications. We welcome submission across all temporal and spatial scales, and especially encourage studies that benefit from synergies between modern and paleo-oceanography, geochemistry, sedimentology, and modeling.

Trace elements and isotopes (TEIs) in the ocean play pivotal roles in primary productivity, carbon cycling, and marine biodiversity, and serve as powerful tracers of oceanic processes. To reliably apply these geochemical proxies, it is essential to develop a thorough understanding of the oceanic distribution of TEIs and physical and chemical processes that influence these patterns. The processes that influence the oceanic TEI distribution include inputs from various sources (e.g., river-estuarine, atmospheric deposition, submarine groundwater discharge, hydrothermal inputs and marine benthic dynamics) and oceanic internal cycling (biological uptake and remineralization, reversible scavenging, particle-water interaction, redox conditions, and ocean circulation). Since the start of the GEOTRACES program, observational TEI datasets have been rapidly accumulating, providing valuable resources to the state-of-the-art ocean modeling tools to test hypotheses and predict distributions in regions that are still poorly constrained. This knowledge not only offers significant insights into the debate about the controls of modern ocean chemistry but also aids in resolving discrepancies arising from conflicting paleo-records of multiple geochemical proxies.

This session invites contributions from observational, experimental, and modeling studies specifically focusing on (i) understanding the TEI distribution, species, and bio-availability in the ocean in connection to various sources and internal cycling, (ii) the impact of processes at oceanic boundaries (atmosphere, land, shelf, hydrothermal vents) on oceanic TEI distributions, (iii) new insights into the processes of open ocean cycling, (iv) application of AI/ML and other modeling techniques in assessing the marine TEI distribution. We encourage submissions based on multi-disciplinary and multi-proxy approaches.

Post-depositional alteration of marine sedimentary aluminosilicates likely plays a significant role in the global biogeochemical cycling of elements with implications for Earth’s climate through time, yet much remains unknown about these processes. In recent years, processes and feedbacks that link carbon cycling and marine silicate alteration have received considerable attention. However, the impacts on other elemental cycles are less discussed, nor do we know enough about the relevant times scales for these processes. Authigenic clay formation and the dissolution of primary silicate minerals and volcanic ash have been shown to regulate the exchange of numerous elements though global assessments are still lacking. We encourage submissions regarding the diverse reactions affecting marine aluminosilicate clay minerals including: marine authigenic clay mineral formation, subseafloor weathering, marine reverse weathering, basalt alteration, volcanic ash alteration, colloid formation, oxic diagenesis, reductive dissolution, and silica diagenesis. In addition, the environmental conditions and early diagenetic processes that promote and inhibit alteration of marine silicate alteration should be further investigated. How do these post-depositional changes to aluminosilicates impact ocean element budgets via fluxes into or out of seawater? How can they alter the paleoceanographic record and what can they tell us about Earth’s ocean-climate dynamics through time? Evidence derived from porewater, solid phase sediment, the water column, laboratory experiments, or sedimentary rocks, including element concentrations, isotopes, mineralogy, modeling, or other approaches is welcome. The goal of this session is to investigate the role of weathering and authigenic aluminosilicates in modern processes, impacts on seawater budgets, paleoceanography, and past climates.

Seafloor hydrothermal systems have profoundly influenced Earth’s biosphere, lithosphere, hydrosphere, and atmosphere throughout Earth history and serve as crucial pathways for the transfer of materials and energy between the lithosphere and the exosphere (biosphere, hydrosphere, and atmosphere) today. Nonetheless, hydrothermal systems’ nature within the oceanic crust drastically limits the temporal extent of direct geologic observations of their existence. Thus, attempts to correlate seafloor hydrothermal processes with biological evolution, global elemental budgets, and global redox states throughout Earth history generally require interdisciplinary efforts that integrate studies of modern systems, interpretations of the geologic record, novel laboratory experiments, and numerical models. Specific focuses could include the role of seafloor hydrothermalism in carbon and other elemental cycles, studies of the linkages between high and low temperature hydrothermal alteration, crustal mineralogy, and seawater geochemistry, and the relation between hydrothermal systems and the tempos and milestones of biological evolution. Submissions from early career researchers are especially welcome.

The stable isotope ratios of oxygen and hydrogen provide unique insights into the climate system on sub daily to orbital timescales and across many spatial scales. Critically, water isotopes provide a link between past and present hydroclimate, as isotope-based paleoclimate proxies record climate variability beyond the instrumental period. Modern studies employing water isotopes provide key insights into ocean-atmosphere interactions, hydrologic balance and moisture processes and provide frameworks for interpreting paleoclimate records. Recent developments have allowed for new and high temporal resolution water isotope observations, increasing isotope monitoring in key regions and inclusion of water isotopes in global climate models. Together, this has open the realm of scientific questions that can be addressed with water isotope data. This session welcomes any work using water isotopes to answer questions regarding past, present or future climate.

Natural hazards are on a slight increase overall, especially those linked to climatic change; however natural disasters clearly show an exponential rise. As a result of growing populations, people are progressively more forced to settle in marginal areas likely to be affected by natural hazards, especially in coastal areas of seas and lakes. In addition to the high population density in these vulnerable coastal regions, key economical activities also take place, such as fisheries, tourism and energy production. Coastal hazard mitigation studies base their information on historical and instrumental data, which, in most cases, are temporally limited. Additionally, these records do not encapsulate a wide range of natural hazard extremes; hence their usefulness is limited. Analyzing the sedimentary record using a wide array of multi-proxy approaches has the potential to reveal how vulnerable and dangerous our coastal environments have been in the past and how previous civilizations have suffered, and perhaps adapted. Can we learn any lessons from the past? This session calls for contributions that provide data from high-resolution multi-disciplinary studies from Quaternary marine, lagoon, lacustrine and coastal sediments, with robust chronological control. It remains crucial that our scientific results are made available to end-users, allowing for mitigation and/or adaptation.

Key words; Climate change, Human, Economic

Atmospheric CO₂ is a key driver of both temperature an essential feedback of the global carbon cycle, and the lead issue of the modern climate crisis. As such, for our immediate future, revealing past atmospheric CO₂ concentrations in geological time is vital for understanding how Earth’s climate has evolved through its history, and to determine the Earth’s myriad carbon cycle-climate interactions. Up to almost 1 million years ago, ice cores provide an accurate and precise estimation of past CO₂ concentrations, but beyond this point, determination of atmospheric CO₂ is dependent on a wide array of indirect proxies, which record trends in past CO₂ concentration as part of fossil biological and (geo)chemical material. Recovering accurate and precise estimates of past CO₂ from preserved geological materials is a challenging but fundamental goal of Earth system science.

In this session we invite studies reconstructing CO₂ concentrations from geological archives or potential geological archives using both well-established and novel methods such as foraminiferal δ¹¹B, the δ¹³C of alkenones and other phytoplankton-derived biomarkers, and other proxies such as reconstructions of land plant gas exchange. We particularly welcome studies which compare different proxy groups or modelling to increase understanding into potential differences between or additional information from multi-proxy records. We also welcome submissions using CO₂ reconstructions in their wider context to shed light on the Earth system through geologic time.

Assessing climate change and the environmental responses to these often dramatic changes has key implications for our understanding of Earth’s history and how Earth will respond to modern climate change. Generating new records of these relationships in the Cenozoic is particularly important since ecosystems in this era closely resemble that of the modern world. Furthermore, terrestrial records are of particular importance due to their direct impact on human populations. This session will focus on highlighting novel records of paleoclimate and paleoenvironmental change during the Cenozoic. Contributions spanning the Cenozoic or from specific intervals such as the Paleocene-Eocene Thermal Maximum, Eocene-Oligocene Transition or Quaternary glacial cycles are encouraged. Likewise, we seek to highlight a wide range of geochemical archives including speleothems, paleosols, lake sediments, and microbialites. Work relating to the development of novel or improved analytical approaches for generating paleoclimatic and paleoenvironmental proxy records are also encouraged.

The polar regions offer exceptional opportunities for geoscientific research, with geochemistry playing a pivotal role in deciphering the geological past and projecting future climate impacts. By analyzing chemical signatures in rocks, sediments, ice cores, and ocean waters, geochemists can reconstruct the tectonic evolution, paleoenvironmental conditions, and paleoclimates that have shaped Antarctica and the Arctic. Geochemical data, such as isotopic and elemental tracers, provide critical insights into the interactions between the cryosphere, lithosphere, hydrosphere, and atmosphere, especially in relation to greenhouse gas (GHG) dynamics and their influence on climate systems across geologic timescales.

This session welcomes contributions that focus on geochemical approaches to studying polar regions, emphasizing the role of GHG cycling, the geochemical processes underlying permafrost thawing, and the subsequent release of carbon and methane into the atmosphere. The amplification of climate change in the Arctic—known as Arctic amplification—is a particularly urgent area of study, as it highlights the enhanced sensitivity of the region to global warming. Contributions addressing the geochemical implications of these processes, alongside the chemical weathering in non-glaciated areas and the interactions between ice sheets, bedrock, and ocean waters, are particularly encouraged.

By spotlighting geochemical investigations, this session aims to deepen our understanding of the geological history of Antarctica and the Arctic, while exploring their critical roles in amplifying climate feedback and shaping the Earth’s future environmental trajectory.

Analysis of deep-time climatic and environmental variation is paramount to progress in understanding fundamental questions of Earth System feedbacks and sensitivity to perturbations (e.g., tipping points and thresholds)—including, but not limited to, extinctions, large igneous provinces, ice ages, hyperthermalism, as well as oceanic acidification and anoxia. However, reconstruction of deep-time climatic and environmental change from sedimentary records remains challenging. New tools are needed to investigate poorly known aspects of paleoenvironmental systems as well as to test interpretations made using established paleoenvironmental proxies.

The scope of this theme session includes novel proxy development as well as new constraints on existing geochemical proxy records. Topics include, but are not limited to, proxy development and calibration in modern and ancient systems (e.g., GEOTRACES), experimental constraints, data-model calibrations, and novel proxy applications in the ancient sedimentary record. We especially encourage submissions with new and innovative insights regarding mechanisms, feedbacks, or quantitative thresholds driving ancient geochemical perturbations and their relationship with environmental, climatic, and biological evolution.

The discipline of geochemistry is continually evolving with the advancement of analytical instrumentation and computational methods, opening new research horizons and allowing researchers to apply analytical toolkits beyond their original intention. In this capacity, geochemistry can act as a hub that opens connections between research silos, or fields, and expand inter- and intra-disciplinary science. The Goldschmidt conference provides an example of the breadth of geochemists’ involvement in diverse research fields. It highlights the potential of geochemistry for contribution to global sustainability and underpins the value of geochemistry for solving real-world problems.

A legacy of Balz Kamber's career has been his ability to connect geochemical silos to answer global geoscience questions with diverse approaches and teams. From Archean crustal evolution to modern chemical weathering, from mantle xenoliths to microbialites and magmatism, Balz has developed novel geochemical approaches and perspectives to tackle Earth processes. In doing so, he has also connected people and ideas across continents with different backgrounds and perspectives. This session in honor of Balz Kamber seeks to celebrate and promote examples of geochemical research that have advanced through the connection of geochemical methods and disciplines. We encourage submissions from researchers at all career stages and from all backgrounds, highlighting any application that can be viewed through the lens of its past and present development due to the unconventional bridging of people, ideas, and geochemical tools.

In today's era of rapidly expanding empirical data and advanced analytics, data processing tools play an integral role in every geoscientist's work. The development and implementation of novel (semi-)automated analytical setups have significantly accelerated data production, enabling deeper insights into the Earth's system. These setups, along with the growing focus on FAIR (Findable, Accessible, Interoperable, Reusable) data policies from funding agencies, emphasize the importance of data reusability and sharing.

As a result, many researchers create their own custom tools, including code snippets, scripts, spreadsheets, and sometimes even full-fledged programs that optimize workflows, compile data, reduce workload, and speed up daily tasks. These self-made tools are often crucial to the research process, but tend to remain hidden behind the final outcomes of the research they support and rarely receive the recognition they deserve.

We again aim to shine a spotlight on these valuable scientific tools, whether they are at the prototype stage or fully developed. We welcome contributions that address:

• scientific tools/apps/software in any coding language and stage of development
• novel data reduction/processing algorithms
• laboratory automation/digitalization projects
• contributions to FAIR data management

and aim to raise the overall awareness of this topic in our scientific field, facilitate sharing and foster collaborations. We prioritize open-source projects and discourage the submission of blackbox tools.

Africa is a continent characterized by its complex geology, abundant mineral deposits, and rich ecosystems. This session aims to unite researchers engaged in geochemical studies across Africa and to provide insights into (i) understanding the geological history and origins of ore deposits, (ii) assessing the current and future development of the mineral resources sector, (iii) addressing the challenges posed by climate change, and (iv) protecting natural resources for sustainable use, including access to safe drinking water and maintaining fertile, healthy soils.

We invite submissions from various disciplines related to rock geochemistry, economic geology with a focus on ore deposits, environmental geochemistry, and the impacts of mining and ore processing. We are also interested in studies that examine other anhtropogenic drivers affecting geoecosystems (including soils, biota, groundwater, and surface water) and human health. Additionally, we welcome research that links geochemistry with public policy and sector initiatives, such as raising awareness of contaminated areas, addressing the legacies of the mining industry, establishing contaminant thresholds, and developing strategies for environmentally responsible mining practices.

In the spirit of transparency and the advancement of science, this session invites scientists from the interdisciplinary fields of geosciences to share their failed hypotheses, research approaches, scientific blunders and experiments that initially looked promising but didn’t exactly go according to plan. While negative results, failed research approaches and experiments often remain hidden in publications, this session is exactly the opposite and celebrates failure by offering a platform to discuss those moments that never made it to publication. By shining a light on what didn’t work and why, this session contributes to the collective knowledge of geochemistry and related fields. We believe that failed stories hold significant value, not just in preventing repetition of the same errors, but also in sparking new ideas by improving formerly failed approaches.

In addition to being informative, this session promises to be fun. Presenters are encouraged to share their stories creatively, with humor and a bit of self-reflection. By sharing what didn’t work, we collectively grow stronger as scientists. We invite all contributions from the diverse and interdisciplinary field of geosciences to submit their stories of failure — this is your chance to let those projects come forward. Submissions should include a brief description of the experiment, scientific approach, or sample set, what went wrong, and what lessons were learned.

Let’s turn our geochemical disasters into learning experiences for the whole community and have a few laughs along the way. Join us in celebrating the failed experiments that make us better scientists!

Elements’ first issue was published in January 2005 as a joint product of five earth science societies. That inaugural issue’s editorial stated, “The grand vision of Elements is to integrate mineralogy, petrology, and geochemistry, and to showcase them to ourselves and to a much broader community.” Twenty years and more than 120 thematic issues later, how well has Elements done? The magazine is now supported by 18 member-based earth science societies, community-sourced proposals for thematic issues consistently exceed its publication capacity, and it has become a valuable educational resource as well as the go-to place for scientists looking to enter a new field of specialization. The Geochemical Society was an Elements founding member, and the European Association of Geochemistry joined as the first issue went to press, so the Goldschmidt meeting is an appropriate setting to bring together Guest Editors and authors of past issues to highlight successes and to assess and explain how publication in Elements has influenced their fields. Such presentations will combine Elements’ signature interdisciplinary appeal with guidance that future Elements Guest Editors and authors can use to further broaden and strengthen the fields of mineralogy, petrology, and geochemistry. Along with formal presentations, a panel-discussion / townhall segment will provide one of the largest gatherings of geochemists, petrologists, and mineralogists the opportunity to hear, discuss, and suggest how Elements can continue to advance our disciplines.

Geochemistry provides useful research tools that support knowledge generation about the fundamental processes in Earth, Environmental and Planetary Sciences. The acquired knowledge and understanding of such processes is essential to develop many strategies in dealing with global challenges and achieving sustainable development goals. To achieve this, we need to attract and retain diverse talent. However, evidence exists for significant and ongoing challenges in retaining diverse talent and fostering an equitable and inclusive community. Many of these challenges are also common in most science and engineering fields. Though, due to the multidisciplinary and multifaceted nature of geochemistry research, (involving laboratory, field and computational approaches) some of these challenges are exacerbated. In combination with uneven access to funding, this can create barriers to certain demographics and increase global inequalities.

In this session we invite presentations that provide insights into the barriers experienced by geochemists of under-represented and marginalised communities throughout the world and how such barriers can be overcome or even obliterated. In this session we accept and welcome presentations discussing research on barriers (related to e.g. awards, recruitment and promotion, field work) and strategies to overcome barriers and increase diversity in geochemistry (e.g. through mentoring, teaching, networks, institutional or national initiatives) but also presentations outlining lived experiences. The session will have no requirement for the format of the presentation, and abstracts to this session will be free of charge and will not prevent the submission of an abstract to another theme as presenting author.

What is geochemistry? Who handles geochemical tools? Are geochemists friendly with other experts in scientific fields? Since its minting, the term geochemistry has been evolving in its meaning and appeal. Born as a rough mixture of chemistry and geology, geochemistry is nowadays living on its own and it is recognised as a science itself. Combining the strength and reliability of chemistry and the open-minded view of geology, geochemistry has helped the comprehension of many geological processes, extending from the deep Earth to the air and up to the universe. Then, pushed by a growing desire to know, geochemistry has met other scientific fields and started helping them to fix apparent tricky problems.

This session is devoted to those who applied geochemical skills and tools to help researchers with a non-geochemical background answer unresolved questions. Geochemical studies conducted by involving apparently incompatible disciplines, including fundamental sciences (e.g., math, chemistry and physics), natural sciences (e.g., biology, microbiology, astronomy), applied sciences (e.g., engineering and medicine) and social sciences (e.g., anthropology, archaeology, economics) are welcomed. Laboratory experiments, empirical investigations and theoretical studies combining different scientific fields with particular stress on geochemistry are awaited for this session. Also, we invite submitting contributions on investigations based on geochemistry as a joint between the diverse scientific disciplines.

GEOROC (https://georoc.eu/) and PetDB (https://search.earthchem.org/) are leading, open-access sources of carefully curated geochemical datasets of terrestrial igneous and metamorphic rock and minerals. They have democratized and thereby revolutionized the use of geochemical data for researchers around the world. These databases provide easy access to comprehensive datasets of millions of geochemical measurements that form the basis of new and exciting research in Earth System Science. Both databases were first released in 1999 and went into full operation in 2000. They serve harmonized compilations of compositional data for rocks, minerals, and melt inclusions from thousands of publications, now totalling >42 million single data values. The primary purpose of such databases is to support exciting new research based on published data from around the globe and to facilitate data analytics and machine learning techniques in modern geochemistry.

This session intends to highlight the role and relevance of these databases in advancing scientific discovery over the past two and a half decades. We invite contributions by anyone who has used GEOROC or PetDB data for their research and in education, industry and policy; and by other data systems that were inspired by PetDB's and GEOROC's approach and success. We invite abstracts that reflect on the history and future of big data in geochemistry and how to provide quality service to the community. Join us to learn more about the various ways GEOROC and PetDB data contribute to the research landscape in geochemistry and beyond (e.g. archaeometry, geohealth, remote sensing).

Keynote Speaker: Marie Traun (Kopenhagen)

There is a growing demand for critical metals to have a safer and sustainable future for a clean energy transition. For that to happen geoscientists need to have a better plan for exploration of these metals. However, there is a huge gap in our collaboration ideas to have successes happen fast enough to reach the net zero goals by 2050.

After our success at the 2024 Goldschmidt, we are eager to continue the theme in the European avenue and continue bridging the gap between academia and industry. There needs to be more synergy between industry and academic institutions to address these global challenges.

To decipher the complex processes controlling geochemistry, a transversal approach is necessary that connects industry and academia. The objective of this session is to foster more industry-academia partnerships to tackle these complex problems by bringing together  researchers investigating geochemistry from both domains. We invite contributions addressing issues related to the energy transition, climate change, environmental pollution, biodiversity loss, etc, with the geochemical toolbox. We also welcome studies that have applied a comprehensive approach not relying solely on one analytical method.

We invite presenters who will showcase stories with top notch scientific results, where they have faced challenges to proceed and have got better results by collaborating with Industry and vice versa. It is not one-way traffic and to have success we must think it from a two way collaboration mindset. We invite presenters from worldwide to inspire and energize the next generation as well.

As a cross-cutting theme, some abstracts related to Theme 14 will be integrated into the other themes of the conference. These presentations will show how the science represented in Themes 1-13 also has a role in informing the public and affecting policy decisions. In order to identify your abstract as relevant to Theme 14, please submit it to this session, 14z, and on the submission form, indicate the other session in Themes 1-13 in which it should ultimately be scheduled. Once your abstract is approved, it will be moved into the related theme and scheduled as part of the session you named. It will retain a link to Theme 14 so that delegates can find it in both its scheduled session and in Theme 14.

Abstract submissions to Theme 14 are free of charge and do not preclude the submission of abstracts to other themes as a presenting author. But please note that to be accepted in Theme 14, abstracts must have a significant component related to informing the public or affecting policy decisions, and not merely a tangential connection.