The annual meeting of the GMPV Division, where members are updated on the activities of the Union and the GMPV team. The outgoing Division President, Marian Holness, will welcome the incoming President, Holly Stein, who will share her plans for taking GMPV forward through the next few years.
A free bagged lunch is provided!

Time is a fundamental variable for the understanding of history and dynamics of Earth and planetary processes. Consequently, precise and accurate determination of crystallisation, deposition, exhumation or exposure ages of geological materials has had, and will continue to have, a key role in the geosciences. In recent years, substantial improvement in spatial and temporal resolution of well-established dating techniques and development of new methods have revealed previously unknown complexity of natural systems and in many cases revolutionised our understanding of rates of fundamental geologic processes.

With this session, we aim to provide a platform to discuss 1) advances in a broad spectrum of geochronological and thermochronological methods (sample preparation, analytical techniques, interpretational and modelling approaches) and 2) applications of such methods to a variety of problems across the Earth sciences, across the geological time and across scales of the process studied. We particularly encourage presentations of novel and unconventional applications or attempts to develop new geo/thermochronometers.

Carbonate minerals are ubiquitous throughout all geological environments in the Earth`s crust, forming via biogenic, marine, diagenetic, hydrothermal, magmatic, and metamorphic processes. Therefore, refining our understanding of carbonate formation can contribute towards addressing important geological and societal problems, such as the Earth`s past and present carbon cycle or the exploration of critical raw materials. The study of carbonate minerals is one that crosses multiple sectors and disciplines, with several novel applications emerging in recent years. Similarly, recent analytical developments allow for the application of geochronological, trace element and isotope geochemical techniques across a wide range of scales and sample materials. To keep track of these emerging techniques, this session aims to bring together an interdisciplinary community working both on method development and on the application of techniques investigating carbonate minerals. We invite geoscientists from all fields (e.g., paleoceanology, economic geology, igneous petrology, carbon storage) to contribute to this session by presenting their research in carbonate geochronology (e.g., U-Pb dating), carbonate trace element geochemistry (e.g., rare earth elements), and carbonate isotope geochemistry (e.g., strontium, clumped isotopes).

Data-driven discovery, including data analytics and visualization, has the potential for wide application and advancement in Earth and planetary sciences. Recent work has led to new directions in geosciences including geostatistics, mathematical geosciences, mineral informatics, geospatial and spatio-temporal data analysis, mineral prospectivity mapping and GIS, and machine-learning algorithms in 2D to 5D considering frequency, space, time, uncertainty, and any possible dimensions of the datasets. These methods increase the efficiency of scientific exploration and provide a great depth of understanding and interpretation of geo- and planetary systems. In this session, we welcome abstracts from (1) scientific results related to the application of any data analytics and visualization methods in mineralogy and geochemistry on Earth or other planetary bodies, (2) related methods and/or (3) data resources and infrastructure development that enables scientific exploration in mineralogy or geochemistry in Earth and planetary systems.

The use and development of numerical tools has steadily increased over the past few decades, especially in Earth Sciences as physical and chemical processes occurring in planetary interiors are not always directly observable from the surface. In petrology and geochemistry, the growing number of thermodynamic modelling softwares and codes and associated thermodynamic databases for minerals, fluids and melts has allowed to target wider P-T range, rock, fluid and melt compositions and study processes with increasing complexity. In addition, the increase in the amount of geochemical data from state-of-the-art instruments (e.g. ICP-MS, microprobe, SIMS) has fostered the development of advanced software solutions for data reduction and interpretation. The ever-increasing size and easy availability of these datasets (e.g. GEOROC, EarthChem and AusGeochem, Sedimentary Geochemistry & Paleoenvironments Project, Geochemical Earth Reference Model) has, in turn, opened up new avenues for extracting statistical information on geological processes.
The main goal of this session is to bring together geochemists, petrologists and data scientists who are either developing, using and/or applying numerical tools to understand geological processes. Topics of interest include (but are not limited to) geochemical and petrological modeling for fluids, melts and solids using major/trace elements or isotopes, thermodynamics and kinetics of petro/geochemical processes, provenance analysis, optimization and testing of databases. Model developers using machine learning, big data or minimization/inversion routines, thermodynamic codes/databases as well as those developing new softwares and tools for data processing and visualization are particularly encouraged to submit an abstract. We recognise that innovations in data analysis from one Earth science discipline are very likely to have applications in another. As a result we strongly encourage submissions from all fields of Earth science including, but not limited to sedimentology, petrology, mineralogy, climatology, oceanography and applied geochemistry.

Environmental systems often span spatial and temporal scales covering different orders of magnitude. The session is oriented toward collecting studies relevant to understand multiscale aspects of these systems and in proposing adequate multi-platform and inter-disciplinary surveillance networks monitoring tools systems. It is especially aimed to emphasize the interaction between environmental processes occurring at different scales. In particular, special attention is devoted to the studies focused on the development of new techniques and integrated instrumentation for multiscale monitoring of high natural risk areas, such as volcanic, seismic, energy exploitation, slope instability, floods, coastal instability, climate changes, and another environmental context.
We expect contributions derived from several disciplines, such as applied geophysics, geology, seismology, geodesy, geochemistry, remote and proximal sensing, volcanology, geotechnical, soil science, marine geology, oceanography, climatology, and meteorology. In this context, the contributions in analytical and numerical modeling of geological and environmental processes are also expected.
Finally, we stress that the inter-disciplinary studies that highlight the multiscale properties of natural processes analyzed and monitored by using several methodologies are welcome.

Finding the best method both to monitor environmental processes occurring at the earth surface and to explore data related to them is a challenge for many scientists. The spatial and temporal extension of a process and the observation scale chosen can strongly conditionate the fully understanding of the phenomenon itself. Further, the structural peculiarities of the geochemical data, describing the composition of the matrices used to monitor the environment, are often capable to hidden meaningful relationships among elements in favor of spurious correlations dependent on the so-called closure effect affecting them.
The intrinsic aim of this session is to propose a comparison of methods, including both innovative monitoring and data elaboration techniques, with the purpose of providing a real time review of the pros and the counter associated to the different approaches reported. All the scientists using geochemical data to evaluate the impact of human activities on the environment and aiming at finding the “best solution” for the spatial and temporal discrimination of contamination are invited to contribute to this session.
Studies on single matrices are welcome although research based on the outcomes of integrated plans based on several matrices, including biological ones, would be of greater interest. Similarly, contributions focusing on data elaboration techniques using multivariate analysis and machine learning are encouraged especially if they consider the compositional nature of geochemical data.

This session is open to all contributions in biogeochemistry and ecology where stable isotope techniques are used as analytical tools, with foci both on stable isotopes of light elements (C, H, O, N, S, …) and new systems (clumped and metal isotopes). We welcome studies from both terrestrial and aquatic (including marine) environments as well as methodological, experimental and theoretical studies that introduce new approaches or techniques (including natural abundance work, labelling studies, multi-isotope approaches).

The nature of Earth’s lithospheric mantle is largely constrained from the petrological and geochemical studies of xenoliths. They are complemented by studies of orogenic peridotites and ophiolites, which show the space relationships among various mantle rocks, missing in xenoliths. Mantle xenoliths from cratonic regions are distinctly different from those occurring in younger non-cratonic areas. Percolation of melts and fluids through the lithospheric mantle significantly modifies its petrological and geochemical features, which is recorded in mantle xenoliths brought to the surface by oceanic and continental volcanism. Basalts and other mantle-derived magmas provide us another opportunity to study the chemical and physical properties the mantle. These various kinds of information, when assembled together and coupled with experiments and geophysical data, enable the understanding of upper mantle dynamics.
This session’s research focus lies on mineralogical, petrological and geochemical studies of mantle xenoliths, orogenic and ophiolitic peridotites and other mantle derived rocks. We strongly encourage the contributions on petrology and geochemistry of mantle xenoliths and other mantle rocks, experimental studies, the examples and models of mantle processes and its evolution in space and time.

The origin and evolution of the continental lithosphere is closely linked to changes in mantle dynamics through time, from its formation through melt depletion to multistage reworking and reorganisation related to interaction with melts formed both beneath and within it. Understanding this history is critical to constraining terrestrial dynamics, element cycles and metallogeny. We welcome contributions dealing with: (1) Reconstructions of the structure and composition of the lithospheric mantle, and the influence of plumes and subduction zones on root construction; (2) Interactions of plume- and subduction-derived melts and fluids with the continental lithosphere, and the nature and development of metasomatic agents; (3) Source rocks, formation conditions (P-T-fO2) and evolution of mantle melts originating below or in the mantle lithosphere; (4) Deep source regions, melting processes and phase transformation in mantle plumes and their fluids; (5) Modes of melt migration and ascent, as constrained from numerical modelling and microstructures of natural mantle samples; (6) Role of mantle melts and fluids in the generation of hybrid and acid magmas.These topics can be illuminated using the geochemistry and fabric of mantle xenoliths and orogenic peridotites, mantle-derived melts and experimental simulations.

Subduction drives plate tectonics, generating the major proportion of subaerial volcanism, releasing >90% seismic moment magnitude, forming continents, and recycling lithosphere. Numerical and laboratory modeling studies have successfully built our understanding of many aspects of the geodynamics of subduction zones. Detailed geochemical studies, investigating compositional variation within and between volcanic arcs, provide further insights into systematic chemical processes at the slab surface and within the mantle wedge, providing constraints on thermal structures and material transport within subduction zones. However, with different technical and methodological approaches, model set-ups, inputs, and material properties, and in some cases conflicting conclusions between chemical and physical models, a consistent picture of the controlling parameters of subduction-zone processes has so far not emerged.

This session aims to follow subducting lithosphere on its journey from the surface down into the Earth's mantle and to understand the driving processes for deformation and magmatism in the over-riding plate. We aim to address topics such as: subduction initiation and dynamics; changes in mineral breakdown processes at the slab surface; the formation and migration of fluids and melts at the slab surface; primary melt generation in the wedge; subduction-related magmatism; controls on the position and width of the volcanic arc; subduction-induced seismicity; mantle wedge processes; the fate of subducted crust, sediments and volatiles; the importance of subducting seamounts, LIPs, and ridges; links between near-surface processes and slab dynamics and with regional tectonic evolution; slab delamination and break-off; the effect of subduction on mantle flow; and imaging subduction zone processes.

With this session, we aim to form an integrated picture of the subduction process, and invite contributions from a wide range of disciplines, such as geodynamics, modeling, geochemistry, petrology, volcanology, and seismology, to discuss subduction zone dynamics at all scales from the surface to the lower mantle, or in applications to natural laboratories.

Movements across faults allow part of Earth’s surface to move in response to forces driven by tectonic plate motions. Mid-oceanic ridges (MORs) provide the unique opportunity to study two of the three known plate motions: divergence (at the ridge axis) and strike-slip motion along transform faults (crosscutting the ridge axis). Knowledge on active and past processes building and altering the oceanic lithosphere has increased over the past 20 years due to improvements in deep sea technologies and numerical modeling techniques. Yet, several questions remain open, such as the relative role of magmatic, tectonic and hydrothermal processes in the building of the oceanic lithosphere at the ridge axis, especially at slow and ultra-slow spreading ridges and at their intersection with transform faults. Transform faults and their older parts, i.e., the fracture zones, are still poorly studied features. For a long time, they were considered as cold and, for fracture zones, inactive; however, evidences of magmatism have been observed inside both features. Given the complex network of faults existing within these structures, they represent ideal pathways for hydrothermal percolation into the Earth’s lithosphere and may therefore play a significant role in the chemical and the thermal budget of the planet, as well as in the fertilization processes of the oceans in nutrients. This session objective is to share recent knowledge acquired along mid-oceanic ridge axes, transform faults and fracture zones. Works using modern deep-sea high-resolution techniques are especially welcome. The session also welcomes recent developments in thermo-mechanical models, which integrate geophysical and geological data with numerical modeling tools, bridging the gap between observations and numerical models.

Vertical motions of the Earth’s lithosphere act as a powerful lens into the dynamic behavior of the asthenosphere and deeper mantle. Surface observations, therefore, provide important constraints on mantle convection patterns through space/time and constitute important constraints for theoretical models and numerical simulations. The asthenosphere is a crucial layer in Earth system.  Its structure and dynamics control processes such as postglacial rebound and dynamic topography, and it plays a crucial role in facilitating plate-like surface motions by reducing horizontal shear dissipation of mantle flow. Vertical motions can now be monitored geodetically with unprecedented precision. At the same time, geological records provide invaluable spatial-temporal information about the deeper history of vertical motion of the lithosphere.  For instance: thermochronological methods, studies of river profiles, sediment provenance, landform analysis, or hiatus mapping at interregional and continental scale. The challenges of using Earth's surface records to better understand asthenospheric and deep Earth processes involve (1) signal separation from other uplift and subsidence mechanisms, such as isostasy and plate tectonics; (2) different spatial resolutions and scales between models and observables; and (3) The challenges of recognizing on what (intercontinental) scales to compile geologic and stratigraphic data.

This session will provide a holistic view of the surface expression of the asthenosphere and deep Earth processes from geodetic to geological time scales using multi-disciplinary methods, including (but not limited to) geodetic, geophysical, geochemical, geomorphological, stratigraphic, and other observations, as well as numerical modeling. Thus, it will provide opportunities for presenters and attendees from a range of disciplines, demographics, and stages of their scientific career to engage in this exciting and emerging problem in Earth science.

Cratons form the stable cores of most continents and preserve an integrated, yet sometimes controversial archive of the evolution of the mantle, crust, atmosphere, hydrosphere, and biosphere for the first two billion years of Earth’s history. In this session, we encourage the presentation of new approaches that improve our understanding on the formation, structure, and evolution of cratonic crust and lithosphere with time. In addition, we welcome contributions from studies of supracrustal cratonic records on the evolution and chemistry of the early surface environments and life. This session aims to bring together scientists from a large range of disciplines to provide an interdisciplinary and comprehensive overview of the field. This includes, but is not limited to, fields such as early mantle dynamics, the formation, evolution and destruction of the early crust and lithosphere, the formation of early land and oceans, the interplay between craton formation and plate tectonics, mineral deposits on cratons, early surface environments and the evolution of the early biosphere.

Dynamical processes shape the Earth and other rocky planets throughout their history; their present state is a result of this long-term evolution. Early on, processes and lifetimes of magma oceans establish the initial conditions for their long-term development; subsequently their long-term evolution is shaped by the dynamics of the mantle-lithosphere system, compositional differentiation or mixing, possible core-mantle reactions, etc.. These processes can be interrogated through observations of the rock record, geochemistry, seismology, gravity, magnetism and planetary remote sensing all linked through geodynamical modelling constrained by physical properties of relevant phases.

This session aims to provide a holistic view of the dynamics, structure, composition and evolution of Earth and rocky planets (including exoplanets) on temporal scales ranging from the present day to billions of years, and on spatial scales ranging from microscopic to global, by bringing together constraints from geodynamics, mineral physics, geochemistry, petrology, planetary science and astronomy.

Tectonics, volcanism, and seismicity are the main constructive agents in shaping planetary surfaces and provide precious information on planetary interiors and evolution. They are driven by both endogenous processes and external triggers such as impact events and tidal forces and are associated with an enormous variety of landforms and structures. Even small bodies such as asteroids and comets, where volcanism and tectonics do not play a dominant role, are still affected by fracturing and faulting as a result of other processes like tides, dynamic loading, and gravitational collapse. The study of such geological processes involves many scientific disciplines including remote sensing observation, experimental modelling, geological mapping, rheological and geomechanical studies, field analogue investigations and geophysics. In particular, seismology is one of the most powerful tools to study the interior of planetary bodies and their tectonic regime. Recently, InSight has provided a wealth of seismological data from Mars. Similarly, the selection of Dragonfly by NASA promises a wealth of seismological observations of Titan. It is also expected that seismology will return to the Moon with the selection of the Farside Seismic Suite to fly to the farside of the Moon on a commercial lander in the next few years, and the Lunar Geophysical Network remaining an encouraged mission concept for a future NASA New Frontiers call. In addition to these mission-driven insights, modelling presents an increasingly powerful tool that can help to estimate the expected tectonics and seismicity of different planetary bodies.

This session aims to look at the broad range of tectonics, seismicity, and volcanism and their interactions on Solar System bodies and explore how we could improve our understanding through comparable processes on Earth.

Hence, we welcome contributions on observations from space missions, as well as theoretical estimates and modelling efforts on volcanism, tectonics, and seismicity occurring on all planetary bodies.

Mineralogy is the cornerstone of many disciplines and is used to solve a wide range of questions in geoscience. This broad session offers the opportunity to explore the diversity of methods and approaches used to study minerals and how minerals behave and evolve in their many contexts. We welcome contributions on all aspects of mineralogy, including environmental, soil science, metamorphic, plutonic, deep Earth, planetary, applied mineralogy, and so on. All approaches are welcome: analytical, experimental and theoretical.

In a scenario of growing supply risk and economic vulnerability, the interest in critical and strategic raw materials has increased, leading to enhancing the exploration of previously subeconomic deposits and the re-evaluation of abandoned mines and mining dumps.
Within the present-day circular economy paradigm, this offers the opportunity to integrate the georesources and environmental studies, aiming to build up a sustainable society.
This session will focus on, but is not limited to, contributions in the fields of mineralogy, petrography, structural geology and geochemistry of critical and strategic raw materials ore deposits, including active and abandoned mining sites. Contributions on the recovery of resources from mining dumps and the environmental assessment and remediation are also welcome.

Minerals are formed in great diversity under Earth surface conditions, as skeletons, microbialites, speleothems, or authigenic cements, and they preserve a wealth of geochemical, biological, mineralogical, and isotopic information, providing valuable archives of past environmental conditions. Furthermore, minerals form and dissolve during diagenesis, which modifies the properties of carbonate and clastic rocks. Understanding processes of fluid-rock interactions and interpreting mineral archives still requires fundamental research, with implications for the reconstruction of Earth’s geological record, as well as for man-made systems for carbon capture, utilisation and storage (CCUS), geothermal energy, or critical mineral resources.

In this session we welcome oral and poster presentations from a wide range of research of topics, including process-oriented studies in modern systems, the ancient rock record, experiments, computer simulations, and high-resolution microscopy and spectroscopy techniques. We intend to reach a wide community of researchers sharing the common goal of improving our understanding of the fundamental processes underlying mineral formation, which is essential to read our Earth's geological archive.

Reactions between fluids and rocks have a fundamental impact on many of the natural and geo-engineering processes across a wide range of scales. At the nano- and micro-scale, these processes can be recorded by the formation of natural patterns in rocks, such as the dendritic patterns, banding patterns, crack patterns, mineralogical replacement, growth patterns or deformation patterns. The visible regularity of pattern structures or textures elucidates the physio-chemical environment during fluid-rock interactions. At the meso- and macro-scale, such processes manifest in localization of deformation, earthquake nucleation caused by high pressure fluid pulses, as well as metamorphic reactions and rheological weakening triggered by fluid flow, metasomatism and fluid-mediated mass transport. Moreover, the efficiency of many geo-engineering processes is partly dependent on fluid-rock interactions, such as hydraulic fracturing, geothermal energy recovery, CO2 storage and wastewater injection. All our observations in the rock record are the end-product of all metamorphic, metasomatic and deformation changes that occurred during the interaction with fluid. Therefore, to investigate and understand these complex and interconnected processes, it is required to merge knowledge and techniques deriving from several disciplines of the geosciences.
We invite multidisciplinary contributions that investigate fluid-rock interactions throughout the entire breadth of the topic, using fieldwork, microstructural and petrographic analyses, geochemistry, experimental rock mechanics, thermodynamic modeling and numerical modeling.

Fluid flow in the Earth’s crust is driven by pressure gradients and temperature changes induced by internal heat. The expression of crustal fluid flow is associated with a range of structural and geochemical processes taking place in the basement and in sedimentary basins. Groundwater, hydrothermal brines and gases circulating in the subsurface interact with local structures across different tectonic and geological settings. Under near-lithostatic conditions fluids and rocks are expelled vertically to the near-surface featuring a variety of surficial geological phenomena ranging from hydrothermal systems to sedimentary and hybrid volcanism and cold seeps both onshore and offshore. These vertical fluid flow expressions and piercement structures are characterized by complex sedimentary deformation and geochemical reactions where life can adapt to thrive in extremely harsh environments making them ideal windows to the deep biosphere. Several studies have shown that CO2- and CH4-dominated (or hybrid) vents played a key role in the evolution of our planet and the cycles of life during several geological eras. Similar structures on other planets are promising sites for exploration where habitable niches could have been present. Furthermore, the elevated pore pressures often encountered in reservoirs at depth make piercements ideal natural laboratories to capture precursors of seismic events and dynamically triggered geological processes. Yet, the geochemical and geophysical processes associated with the evolution of these vertical fluid flow features and piercements remain poorly understood.
This session welcomes contributions from the community working on magmatic and sedimentary environments and the domains where they interact on Earth and in the Universe using geophysical, geochemical, microbial, geological, remote sensing, numerical and laboratory studies to promote a better understanding of modern and paleo fluid-driven systems in the upper crust. In particular we call for contributions from: 1) investigations of tectonic discontinuities pre-existing geological structures; 2) the geochemical reactions occurring at depth and at the surface including microbiological studies; 3) geophysical imaging and monitoring of fluid flow systems associated with vertical fluid expulsion at the upper crust; 4) experimental and numerical studies about fluid flow evolution; 5) studies of piercement dynamics related to climatic and environmental implications.

Hydrothermal systems exert crucial influence on volcanic hazards. For example, hydrothermal alteration can reduce the strength of edifice- and dome-forming rocks, increasing the likelihood of volcano spreading and flank collapse, and high pore pressures that develop within hydrothermal systems can promote phreatic/phreatomagmatic explosions and further increase volcano instability. On the other hand, hydrothermal systems also offer the opportunity to exploit minerals of economic interest, and their heat can be harnessed to produce energy. A detailed understanding of hydrothermal systems, fluid-rock interactions in hydrothermal systems, and the resulting effects of alteration, using multidisciplinary studies, is required to better anticipate the hazards posed, to exploit the economic opportunities they provide, and to execute engineering design. We invite diverse contributions dedicated to the characterisation, imaging, monitoring, and hazard/economic assessment of volcanic hydrothermal systems and associated fluid-rock interactions. Contributions can be based on fieldwork, laboratory work, modelling, or a combination of these approaches. Because understanding hydrothermal systems requires multidisciplinary, collaborative teamwork, we welcome contributions based on any subdiscipline (e.g., geology, geophysics, geochemistry, engineering) and using any technique or method (e.g., geological mapping, magnetic, gravity, and spectroscopic methods, laboratory experiments, gas monitoring, numerical modelling). It goes without saying that we hope to have a diverse session in terms of both speakers and audience.

Fluids permeate and diffuse within the crust being originated by internal or external natural sources or by industrial activities for modern energy exploitation and production. Fluids are involved in several geological processes occurring within the seismogenic crust. Fluid-induced stress changes (seasonal forcing due to surface water redistribution, overpressure within the natural reservoirs and/or along the fault planes, industrial wastewater injection, etc.) can reactivate faults and generate deformation and earthquakes. In volcanic environments, fluids play a key role in governing the evolution of magmatic processes and eruption. In this view, it becomes crucial to reliably image fluid storages and track their movement through the crust. New and innovative methodologies and technologies permit 1) to reconstruct the 4D (space and time) variations of rock physical and geochemical properties in a fluid-filled porous medium, 2) detecting and tracking fluids migration, and 3) studying fluid-related effects (such as induced microseismicity, electric properties changes and surface ground deformation). Hence the scientific communities have a new generation of powerful tools for seismic, volcanic and industrial hazard assessment.
This session focuses on main results obtained within the project FLUIDS funded by the Italian Ministry for Research, which was aimed at developing and applying an integrated multi-parametric and multi-disciplinary approach to image and track crustal fluids at selected test-sites in volcanic, tectonic and industrial exploitation environments. The session focuses also on latest research, field studies, modelling aspects, theoretical, experimental and observational advances on detection and tracking of fluid movements and/or pore fluid-pressure diffusion in different environments worldwide, and on the analysis of their correlation with the induced/triggered seismicity.
We welcome contributions on advances in seismic, geochemical and deformation monitoring; multidisciplinary studies combining different data types and observations; characterization and space-time variations of electrical and seismic elastic/anelastic crustal properties, including stress and pressure changes; and physical and/or statistical analyses for the recognition of peculiar seismicity patterns. The session also encourages contributions from early career scientists.

Metamorphic rocks are witnesses to the tectonic and geodynamic processes that shaped the global lithosphere. The record of their journey through time and space is written in their fabrics and assemblages. Resolving the "how, where and when" of metamorphic processes is crucial in the development of models describing regional and global tectonic processes, the transfer of elements within and between the crust and mantle, and the geodynamic evolution of the Earth.

With new methods and insights come new ways to interrogate metamorphic rocks, to constrain the cause and impact of metamorphic reactions, and to investigate secular changes in tectonic processes through time. This session aims to celebrate accomplishments made in the field, and to provide a platform for sharing and exploring innovative ways to investigate metamorphic processes across tectonic settings and geologic time. We invite contributions in metamorphic petrology, field research, geochronology, geochemistry, numerical modelling and tectonics, and especially welcome contributions that employ novel or cross-disciplinary approaches to make metamorphic rocks tell their story.

Garnet is likely the most useful mineral to understand the evolution of basement areas on Earth. Many aspects of the metamorphic evolution of rocks can be unravelled by studying its zoning and inclusion pattern. In addition, garnet can be a treasure chest of mineral, melt and fluid inclusions capable to provide insights into the often obscures prograde/peak metamorphic history of the host rock evolution. Garnets in peraluminous granitoids offer windows into their genetic processes when they are entrained material originating from the source, or on the magma evolution if magmatic in origin. Finally, recent analytical developments in garnet dating offers new possibilities to characterize and better constrain the temporal evolution of a wealth of deep processes, from partial melting to skarn formation to subduction zone dynamics.
We invite our colleagues geoscientists, being them petrologists, geochemists, petrochronologists and structural geologists to present their studies involving (but not limited to) garnet as a crucial petrological tool to better understand Nature. Studies of fluid, melt and mineral inclusions in garnets and application of new analytical techniques, methodological approaches and dating protocols are welcome!

Ophiolites, mélanges, and blueschists (OMB) are significant components of both accretionary and collisional orogenic belts and provide critical quantitative constraints for the timing of rift-drift, seafloor spreading and subduction initiation, ophiolite emplacement and collision events, peak P–T conditions during orogeny, and exhumation within subduction channels and along suture zones. Typical accretionary orogenic belt examples are exposed around the circum-Pacific region and in the Central Asian Orogenic Belt, whereas characteristic collisional orogenic belts occur in the circum-Mediterranean region, Alpine–Himalayan–Tibetan belt, Uralides, Taiwan and Papuan belts, Tasmanides, and Appalachians. Ophiolites and mélanges in these two major types of orogenic belts may show major differences in their crustal anatomies and geochemical fingerprints.

Collectively, OMB complexes and ocean plate stratigraphy (OPS) assemblages display the archives of ocean basin development, subduction initiation, crustal growth via accretionary processes (i.e., offscraping–shallow underplating) and volcanic arc formation at convergent margins, deep tectonic underplating and exhumation within subduction channels, and thermal evolution of subducting slabs. Therefore, systematic documentation of the tectonomagmatic settings of ophiolite formation, mechanisms and processes of mélange development (including non-metamorphosed ones), and P-T-t paths of both blueschist assemblages and high–temperature metamorphic belts in orogenic belts provide significant constraints for a quantitative establishment of the Wilson Cycle evolution of ancient ocean basins and the geodynamics of accretionary and collisional orogenic belt development.

This session will provide an international forum for interdisciplinary presentations and discussions on the diverse origins of OMB terrains and OPS assemblages, and their significance in probing the crustal anatomy and geodynamic evolution of accretionary and collisional belts around the world in a multi-scale approach. We welcome contributions dealing with the structural geology–tectonics, geochemistry–petrology, geochronology, and geophysics–geodynamics of OMB and OPS terrains, as well as numerical and analogue modelling of divergent and convergent margin processes that involve OMB evolution.

The goal of this session is to reconcile short-time/small-scale and long-time/large-scale observations, including geodynamic processes such as subduction, collision, rifting, or mantle lithosphere interactions. Despite the remarkable advances in experimental rock mechanics, the implications of rock-mechanics data for large temporal and spatial scale tectonic processes are still not straightforward, since the latter are strongly controlled by local lithological stratification of the lithosphere, its thermal structure, fluid content, tectonic heritage, metamorphic reactions, and deformation rates.

Mineral reactions have mechanical effects that may result in the development of pressure variations and thus are critical for interpreting microstructural and mineral composition observations. Such effects may fundamentally influence element transport properties and rheological behavior.
Here, we encourage presentations focused on the interplay between metamorphic processes and deformation on all scales, on the rheological behavior of crustal and mantle rocks, and time scales of metamorphic reactions in order to discuss
(1) how and when up to GPa-level differential stress and pressure variations can be built and maintained at geological timescales and modeling of such systems,
(2) deviations from lithostatic pressure during metamorphism: fact or fiction?
(3) the impact of deviations from lithostatic pressure on geodynamic reconstructions.
(4) the effect of porous fluid and partial melting on the long-term strength.
We, therefore, invite the researchers from different domains (rock mechanics, petrographic observations, geodynamic and thermo-mechanical modeling) to share their views on the way forward for improving our knowledge of the long-term rheology and chemo-thermo-mechanical behavior of the lithosphere and mantle.

In the last few decades, the ideas on the architecture and evolution of volcanic and igneous plumbing systems (VIPS) were profoundly modified. The classical paradigm of the magma reservoir as a large and long-lived liquid-rich region slowly fractionating has been challenged by the view of liquid-poor crystal mush that is repeatedly rejuvenated over the lifespan of the magmatic system. Besides, mushy regions, multiphase regions where melt and solid coexist, appear in various other natural contexts, like sea ice, Earth's-core dynamics, icy moons or general fluid mechanics.

Recent research applying various methods to study these systems have shed light on this complexity, however many questions remain as areas of active research and debate:
• How do plumbing systems develop? How do they evolve over time and in different tectonic settings?
• What are the triggering mechanisms for volcanic eruptions in these systems (e.g., magma reservoir vs mush system)?
• How do magma ascent and dyke propagation occur? Do they occur differently in mush systems?
• What do current monitoring techniques tell us about plumbing systems and precursory phenomena of magma ascent and eruption?
• How do mushy regions evolve? How do processes like thermal and compositional convection, segregation of components, and phase changes work?

This session aims to bring together scientists working in different fields of igneous petrology and geochemistry, structural geology, geodesy, geophysics and material sciences. Studies using different methods such as field studies, compositional and textural analyses, geochronology, structural and metamorphic geology, laboratory experiments, numerical/analogue modelling, and seismic and ground deformation surveys to understand the architecture and dynamics of VIPS as well as the evolution of mushy regions are the core of this session. We, therefore, invite contributions highlighting insights from one of these fields and highly encourage contributions using multi-disciplinary approaches.

This session is sponsored by the IAVCEI Commission on Volcanic and Igneous Plumbing Systems.