GD – Geodynamics
Programme group chair:
Jeroen van Hunen
MAL11
Augustus Love Medal Lecture by Thorsten W. Becker & GD Division Outstanding ECS Award Lecture by Ágnes Király
Orals
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Mon, 24 Apr, 19:00–20:00 (CEST)
Room G2
DM5
Division meeting for Geodynamics (GD)
Wed, 26 Apr, 12:45–13:45 (CEST)
Room D2
GD1 – Mantle Dynamics and Plate Tectonics
Programme group scientific officer:
Paul Tackley
GD1.1
Improving our understanding of the mantle requires an interdisciplinary approach, combining investigations into fluid dynamic processes, the role of melts and volatiles, and the mantle's present-day structure and its evolution through the geological past. In particular, the present-day structure of Earth's mantle — in terms of seismic velocity, density, conductivity, rheology, and other physical properties — is a crucial constraint for understanding Earth's dynamics and evolution. Recent breakthroughs in joint modelling/inversion of geophysical fields, petrology, transport phenomena and mineral physics allow for a more accurate description of Earth's upper mantle, providing tighter bounds on the physical and chemical processes that it hosts, and linking the evolution of our planet’s surface to its deep interior.
One such link comes via volcanism, our understanding of which remains incomplete. Intra-plate volcanism manifests irrespective of plate boundaries and includes volcanic fields with diverse characteristics and uncertain dynamical origin. Historically, studies have focused on voluminous lava fields and ocean-island tracks, with many now believed to mark the surface expression of mantle plumes. More recently, alternative driving mechanisms, such as edge-driven convection and shear-driven upwelling, have been explored to explain the generation of smaller intra-plate volcanic fields. To further improve our comprehension of intra-plate volcanism, it is critical to determine the applicability of these dynamical mechanisms across different geological settings and to understand how they interact and evolve in space and time.
For this session, we invite contributions integrating multiple methodologies/datasets to address the current state, evolution and interaction with the lithosphere of Earth's upper mantle. We particularly welcome contributions targeting the nature of mantle melts and the generation of intra-plate volcanism. Topics covered by this session include (1) combined dataset inversions through Bayesian and machine learning approaches, (2) dynamic modelling of deep-rooted mantle plumes and their magmatic expression, (3) investigations of possible shallower melt-generation mechanisms, and (4) the role of melts and volatiles in the evolution of Earth and other planetary interiors.
Orals
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Mon, 24 Apr, 14:00–17:55 (CEST)
Room D3
Mon, 14:00
Mon, 10:45
Mon, 10:45
GD1.3
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.
Orals
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Mon, 24 Apr, 08:30–12:30 (CEST)
Room D3
GD2 – Melts, Volatiles and Chemistry of the Mantle (in partnership with GMPV)
Programme group scientific officer:
Jeroen van Hunen
GD2.2
| PICO
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.
PICO
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Mon, 24 Apr, 08:30–10:15 (CEST)
PICO spot 2
GMPV7.3
Magma dynamics from sources in the upper mantle and lower crust to volcanic eruption at the surface or plutonic emplacement in the shallow crust includes a range of complex phenomena. Fluid-mechanical and thermo-chemical interactions between the different phases (liquid melt, solid crystals, exsolved volatile fluid or vapour, and pyroclasts) emerge on sub-millimetre scales but give rise to interlinked systems of melt extraction, magma ascent, differentiation (e.g., fractional crystallization, magma mixing and mingling, rock assimilation, melt-rock and melt-crystal mush reactions), and storage, eruption, and mineral resource generation extending from several metres to dozens of kilometres throughout the lithosphere and crust. Evidence for these processes derives from geophysical tomography, seismic, acoustic, and ground deformation monitoring, as well as geochemical analyses of volcanic and plutonic products. Observations are complemented by study of experimental petrology, thermodynamic and mechanical properties of magmas. Most observational and experimental methods, however, only provide indirect access to the systems of interest. Computational modelling can therefore provide powerful tools for interpreting and synthesising the wealth of observational and experimental data.
This session aims to stimulate discussions on how mult-idisciplinary approaches can be used to advance the interpretation of volcano monitoring, geophysical, geochemical, and petrological observations. We therefore wish to bring together contributions on the theory and implementation of models of magmatic systems and their application in the context of experimental and observational studies. We invite contributions focusing on (but not restricted to) multiphase flow, thermodynamic phase equilibria, as well as studies on melt extraction from sources in the mantle and crust, magma ascent and storage in the crust, interaction between magma and wall-rocks, crystallization and fluid exsolution dynamics, dissolved and exsolved volatiles in magmas, effusive and explosive eruption dynamics, rheology of solid-liquid-gas mixtures, fragmentation processes, magmatic-hydrothermal interactions, and associated mineral resource genesis.
Orals
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Fri, 28 Apr, 16:15–18:00 (CEST)
Room 0.14
GMPV2.1
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.
Orals
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Tue, 25 Apr, 10:45–12:30 (CEST)
Room -2.47/48
GMPV8.1
The session deals with the documentation and modelling of the tectonic, deformation and geodetic features of any type of volcanic area, on Earth and in the Solar System. The focus is on advancing our understanding on any type of deformation of active and non-active volcanoes, on the associated behaviours, and the implications for hazards. We welcome contributions based on results from fieldwork, remote-sensing studies, geodetic and geophysical measurements, analytical, analogue and numerical simulations, and laboratory studies of volcanic rocks.
Studies may be focused at the regional scale, investigating the tectonic setting responsible for and controlling volcanic activity, both along divergent and convergent plate boundaries, as well in intraplate settings. At a more local scale, all types of surface deformation in volcanic areas are of interest, such as elastic inflation and deflation, or anelastic processes, including caldera and flank collapses. Deeper, sub-volcanic deformation studies, concerning the emplacement of intrusions, as sills, dikes and laccoliths, are most welcome.
We also particularly welcome geophysical data aimed at understanding magmatic processes during volcano unrest. These include geodetic studies obtained mainly through GPS and InSAR, as well as at their modelling to imagine sources.
The session includes, but is not restricted to, the following topics:
• volcanism and regional tectonics;
• formation of magma chambers, laccoliths, and other intrusions;
• dyke and sill propagation, emplacement, and arrest;
• earthquakes and eruptions;
• caldera collapse, resurgence, and unrest;
• flank collapse;
• volcano deformation monitoring;
• volcano deformation and hazard mitigation;
• volcano unrest;
• mechanical properties of rocks in volcanic areas.
Orals
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Fri, 28 Apr, 08:30–12:25 (CEST)
Room D1
GD3 – Dynamics and Evolution of Earth and Terrestrial Planets (in partnership with PS)
Programme group scientific officer:
Jeroen van Hunen
GD3.1
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.
Orals
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Mon, 24 Apr, 14:00–17:55 (CEST)
Room -2.47/48
Mon, 14:00
Tue, 08:30
Tue, 08:30
GD3.2
| PICO
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.
PICO
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Wed, 26 Apr, 14:00–18:00 (CEST)
PICO spot 3a
PS4.2
In June 2021, NASA and ESA selected a fleet of three international missions to Venus. Moreover, the ISRO orbiter mission Shukrayyan-1 is currently in preparation for launch in the mid 2020s. With the ‘Decade of Venus’ upon us, many fundamental questions remain regarding Venus. Did Venus ever have an ocean? How and when did intense greenhouse conditions develop? How does its internal structure compare to Earth's? How can we better understand Venus’ geologic history as preserved on its surface as well as the present-day state of activity and couplings between the surface and atmosphere? Although Venus is one of the most uninhabitable planets in the Solar System, understanding our nearest planetary neighbor may unveil important lessons on atmospheric and surface processes, interior dynamics and habitability. Beyond the solar system, Venus’ analogues are likely a common type of exoplanets, and we likely have already discovered many of Venus’ sisters orbiting other stars. This session welcomes contributions that address the past, present, and future of Venus science and exploration, and what Venus can teach us about exo-Venus analogues. Moreover, Venus mission concepts, new Venus observations, exoplanet observations, new results from previous observations, and the latest lab and modelling approaches are all welcome to our discussion of solving Venus’ mysteries.
Orals
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Fri, 28 Apr, 08:30–10:15 (CEST)
Room L1
Fri, 08:30
Thu, 16:15
Thu, 16:15
GM9.1
It is now well known that the coupling between tectonics, climate and surface processes governs the dynamics of mountain belts and basins. However, the amplitude of these couplings and their exact impact on mountain building are less understood. First order quantitative constraints on this coupling are therefore needed. They can be provided by geomorphic and sedimentary records including longitudinal river profiles, fluvial and marine terraces, landslides, downstream fining trends, growth strata, sediment provenance, sequence stratigraphy, and changing depositional environments. In addition, such interaction may be explored also by geodetic analyses (e.g., GPS, UAV and satellite images analyses) as well as with innovative geo-informatic approaches. Moreover, the increasing integration of geochronological methods for quantifying erosion rates and source-to-sink sediment transfer with landscape evolution, stratigraphic, climatic, and tectonic models allows us to advance our understanding of the interactions between surface processes, climate and tectonic deformation.
We invite contributions that use geomorphic, geochronologic and/or sedimentary records to understand tectonic deformation, climate histories, and surface processes, and welcome studies that address their interactions and couplings at a range of spatial and temporal scales. In particular, we encourage coupled catchment-basin studies that take advantage of numerical/physical modelling, geochemical tools for quantifying rates of surface processes (cosmogenic nuclides, low-temperature thermochronology, luminescence dating) and high resolution digital topographic and subsurface data. We invite contributions that address the role of surface processes in modulating rates of deformation and tectonic style, or of tectonics modulating the response of landscapes to climate change.
Orals
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Fri, 28 Apr, 08:30–12:15 (CEST)
Room D3
Fri, 08:30
Fri, 14:00
Fri, 14:00
GD4 – Subduction and Orogeny
Programme group scientific officer:
Antoniette Grima
GD4.2
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.
Orals
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Thu, 27 Apr, 08:30–12:30 (CEST), 14:00–15:45 (CEST)
Room D1
Thu, 08:30
Fri, 08:30
Fri, 08:30
GD4.3
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.
Orals
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Tue, 25 Apr, 16:15–18:00 (CEST)
Room -2.91
Tue, 16:15
Tue, 14:00
Tue, 14:00
GD4.4
Convergent plate boundaries can result in a wide variety of tectonic feature from collisional orogens (e.g. the Himalaya or Pyrenees) through subduction orogens (e.g. the Andes or Taiwan) to arc-back-arc systems (e.g. Sea of Japan or the Aegean). These tectonic settings might transition from one to another like in Southeast Asia, where there is geodynamic inversion of the east dipping Manila oceanic subduction South of Taiwan, that evolves northward, first, into a Continental Subduction (collision) onshore Taiwan, then secondly, east of Taiwan, into the north dipping Ryukyu arc/continent subduction.
Recently a large volume of high quality and high resolution geophysical and geological data had been acquired that could help us better understand the processes that govern subduction, collision and back-arc extension. Our session has a special focus on overriding plate deformation as it shows a great variety between different systems from extension dominated settings to compression dominated ones.
In this session authors are encouraged to share their work on the tectonic or magmatic features convergent plate boundary settings, as well as on the study of the processes contributing to the formation, evolution, and shaping of such systems. The conveners encourage contributions using multi-disciplinary and innovative methods from disciplines such as, but not restricted to, field geology, thermochronology, geochemistry, petrology, seismology, geophysics and marine geophysics, and analogue/numerical modelling.
Orals
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Thu, 27 Apr, 16:15–18:00 (CEST)
Room D1
Thu, 16:15
Fri, 08:30
Fri, 08:30
GD5 – Rifting and Mid Ocean Ridges
Programme group scientific officer:
Antoniette Grima
GD5.1
It is becoming increasingly apparent that continental rifting, breakup, and ocean spreading involve complexities not easily explained by standard models, especially in oblique and transform settings. The unexpected discovery of continental material far offshore, e.g. at the Rio Grande Rise, and realisation of the importance of obliquity and time-dependence in rifting, challenge conventional tectonic models. This session aims to bring together new observations, models, and ideas to help us understand the complex factors influencing continental rifting, breakup and ocean spreading, including oblique and transform settings. Works investigating time-dependant controls on rifting mechanisms, plate kinematics, strain localisation, obliquity, plate interior deformation, inherited lithospheric structures, interaction and feedbacks of rift processes, lithospheric and mantle derived driving forces, magmatism, syn-rift sedimentation, and other controls on rifting, are therefore welcomed to this session. Contributions from any geoscience discipline, including marine geophysics, seismology, ocean drilling, geochemistry, petrology, plate kinematics, tectonics, structural geology, numerical and analogue modelling, sedimentology and geochronology etc., are sought. We particularly encourage cross-disciplinarity, the spanning of spatio-temporal scales, and thought-provoking studies that challenge conventions from any and all researchers.
Orals
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Thu, 27 Apr, 08:30–10:15 (CEST)
Room -2.91
GD5.2
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.
Orals
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Wed, 26 Apr, 08:30–10:15 (CEST), 10:45–12:30 (CEST)
Room -2.47/48
TS5.1
Continental rifting is a complex process spanning from the inception of extension to continental rupture or the formation of a failed rift. This session aims at combining new data, concepts and techniques elucidating the structure and dynamics of rifts and rifted margins. We invite submissions highlighting the time-dependent evolution of processes such as: initiation and growth of faults and ductile shear zones, tectonic and sedimentary history, magma migration, storage and volcanism, lithospheric necking and rift strength loss, influence of the pre-rift lithospheric structure, rift kinematics and plate motion, mantle flow and dynamic topography, as well as break-up and the transition to sea-floor spreading. We encourage contributions using multi-disciplinary and innovative methods from field geology, geochronology, geochemistry, petrology, seismology, geodesy, marine geophysics, plate reconstruction, or numerical or analogue modelling. Special emphasis will be given to presentations that provide an integrated picture by combining results from active rifts, passive margins, failed rift arms or by bridging the temporal and spatial scales associated with rifting.
Orals
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Wed, 26 Apr, 14:00–18:00 (CEST)
Room K1
Wed, 14:00
Wed, 10:45
Wed, 10:45
GD6 – Crust, Lithosphere and Asthenosphere
Programme group scientific officer:
Irina M. Artemieva
GD6.4
We invite, in particular multidisciplinary, contributions which focus on the structure, deformation and evolution of the continental crust and upper mantle and on the nature of mantle discontinuities. The latter include, but are not limited to, the mid-lithosphere discontinuity (MLD), the lithosphere-asthenosphere boundary (LAB), and the mantle transition zone, as imaged by various seismological techniques and interpreted with interdisciplinary approaches. Papers with focus on the structure of the crust and the nature of the Moho are also welcome.
The session topic is interpretation and modelling of the geodynamic processes in the lithosphere-asthenosphere system and the interaction between crust and lithospheric mantle, as well as the importance of these processes for the formation of the discontinuities that we today observe in the crust and mantle. We aim at establishing links between seismological observations and process-oriented modelling studies to better understand the relation between present-day fabrics of the lithosphere and contemporary deformation and ongoing dynamics within the asthenospheric mantle. Methodologically, the contributions will include studies based on application of geochemical, petrological, tectonic and geophysical (seismic, thermal, gravity, electro-magnetic) methods with emphasis on integrated interpretations.
Orals
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Mon, 24 Apr, 16:15–18:00 (CEST)
Room M1
Mon, 16:15
Mon, 14:00
Mon, 14:00
GMPV6.1
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.
Orals
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Mon, 24 Apr, 16:15–18:00 (CEST)
Room N1
Mon, 16:15
Mon, 14:00
Mon, 14:00
GD7 – Rheology and Multiscale Mineralogy in Geodynamics
Programme group scientific officer:
Frederic Deschamps
GD7.1
Many regions of the Earth, from crust to core, exhibit anisotropic fabrics which can reveal much about geodynamic processes in the subsurface. These fabrics can exist at a variety of scales, from crystallographic orientations to regional structure alignments. In the past few decades, a tremendous body of multidisciplinary research has been dedicated to characterizing anisotropy in the solid Earth and understanding its geodynamical implications. This has included work in fields such as: (1) geophysics, to make in situ observations and construct models of anisotropic properties at a range of depths; (2) mineral physics, to explain the cause of some of these observations; and (3) numerical modelling, to relate the inferred fabrics to regional stress and flow regimes and, thus, geodynamic processes in the Earth. The study of anisotropy in the Solid Earth encompasses topics so diverse that it often appears fragmented according to regions of interest, e.g., the upper or lower crust, oceanic lithosphere, continental lithosphere, cratons, subduction zones, D'', or the inner core. The aim of this session is to bring together scientists working on different aspects of anisotropy to provide a comprehensive overview of the field. We encourage contributions from all disciplines of the earth sciences (including mineral physics, seismology, magnetotellurics, geodynamic modelling) focused on anisotropy at all scales and depths within the Earth.
Orals
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Tue, 25 Apr, 14:00–17:35 (CEST)
Room -2.47/48
GD7.2
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.
Orals
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Fri, 28 Apr, 08:30–10:15 (CEST)
Room D2
TS1.3
A detailed understanding of the stress state and variable geomechanical properties (frictional strength, Young's modulus, etc.) of the Earth's crust are important parameters for lithosphere dynamics as well as engineering applications related to the extraction, transport, storage and disposal of energy or materials.
In the context of lithosphere mechanics, the strength limits are bounded by two end-members. In one end-member model, the crust is strong and fails at high differential stresses (hundreds of MPa) consistent with the classical Christmas tree envelope and static friction governed by Byerlee's law. In the other end-member model, the crust is weak and fails at low differential stresses (tens of MPa) consistent with stress magnitudes that may result from topographic loading and tectonic forces. How significant are these end-member scenarios and how do they affect our perception of lithosphere dynamics on time scales ranging from a single earthquake to long-term processes such as orogeny? Can the end-members be reconciled or are they mutually exclusive? Do they reflect differences between continental interiors and plate margins or tectonically inactive and active regions?
Geomechanics is focused on providing the most accurate estimate of the present-day stress state, or quantifying criticality in the context of subsurface use. More complex questions can be addressed with numerical models. But how can the uncertainties of model parameters (material properties and structures) and calibration data (stress magnitudes) be quantified?
To address these fundamental questions, we invite contributions from observational, experimental, theoretical, and numerical studies that improve our understanding of the crustal stress state or expand the methodological repertoire. Highly appreciated are presentations about new methods and on strategies to reduce the uncertainties.
Orals
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Mon, 24 Apr, 10:45–12:30 (CEST)
Room D1
Mon, 10:45
Mon, 16:15
Mon, 16:15
Programme group scientific officer:
Phil Livermore
GD8.1
| PICO
Understanding the structures and dynamics of the core of a planet is essential to constructing a global geochemical and geodynamical model, and has implication on the planet's thermal, compositional and orbital evolution.
Remote sensing of planetary interiors from space and ground based observations is entering a new era with perspectives in constraining their core structures and dynamics. Meanwhile, increasingly accurate seismic data provide unprecedented images of the Earth's deep interior. Unraveling planetary cores' structures and dynamics requires a synergy between many fields of expertise, such as mineral physics, geochemistry, seismology, fluid mechanics or geomagnetism.
This session welcomes contributions from all the aforementioned disciplines following theoretical, numerical, observational or experimental approaches.
PICO
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Thu, 27 Apr, 10:45–12:30 (CEST)
PICO spot 2
GD9 – Geodynamics of Specific Regions
Programme group scientific officer:
Frederic Deschamps
GD9.1
We invite contributions based on geological, tectonic, geophysical and geodynamic studies of the Tethyan Belt, Central Asia, and the Circum Pacific margins. We particularly invite interdisciplinary studies, which integrate observations and interpretations based on a variety of methods. This session will include a suite of studies of these regions with the aim of providing a comprehensive overview of their formation and evolution, influence of the tectonic features on climate, biodiversity, human habitat, and topographic change.
The Tethyan Belt is the most prominent collisional zone on Earth, covering the vast area between far eastern Asia and Europe. The geological-tectonic evolution of the belt has led to significant along-strike heterogeneity in its various regions, including the SE-Asian subduction-collision system, the Tibetan-Himalayan region, the Iranian Plateau, Anatolia, and the Alpine orogen. The Tethyan Belt is the result of subduction of the Tethyan Oceans, including significant terrane amalgamation, and collisional tectonics along the whole belt. The belt is today strongly affected by the ongoing collision of Eurasia with the African, Arabian and Indian plates and the large-scale geometry of the Cenozoic mountain ranges is often determined by inherited features. The long formation history and the variability of tectonic characteristics and deep structure of the region make it a natural laboratory for understanding the accretion processes that have shaped the Earth through its history and have led to the formation of vast resources in the crust.
The circum-Pacific domain has been undergoing multiple re-orientations in subduction and given rise to basin-mountain systems in both the eastern and western Pacific continental margins since the late Mesozoic. We welcome contributions on (1) the formation/origin and evolution of lithosphere architecture, (2) spatial-temporal evolution of Earth’s surface topography, (3) evolution of basin-mountain systems, and (4) 4-D geodynamic models of eastern and western Pacific continental margins.
Orals
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Fri, 28 Apr, 10:45–12:30 (CEST), 14:00–15:45 (CEST), 16:15–18:00 (CEST)
Room D2
Fri, 10:45
Fri, 08:30
Fri, 08:30
GMPV10.1
The crystalline areas of Europe are formed predominantly by rocks of Variscan age (370-300 Ma), or older rocks that underwent a Variscan metamorphic overprint. The interest in this continent-scale orogeny is sourced in the fact that the reconstruction of Variscan geodynamics requires the development and reconsideration of fundamental concepts of orogenic cycling. We need to explain the evolution of Variscan cycle via the existence of multiple, partly opposing subduction zones, as well as periods of lithospheric thinning and ultrarapid exhumation during extensional stages, or oroclinal bending. These orogenic processes are reconstructed based on information from transcrustal magmatic systems that established during pre-, syn and post-collisional stages as well as from understanding of P-T-t evolution in the different metamorphic units. Especially linking geochronological, isotopic and petrological records led to significant advances in understanding the evolution of both magmatic and metamorphic rocks. We invite contributions from all fields that investigate the nature, conditions and the timing of orogenic processes, crustal melting, or the structure of the lithosphere, through analytical or numerical approaches. Recent advances linking geochronological and petrological records are welcomed.
Orals
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Tue, 25 Apr, 14:00–15:45 (CEST)
Room 0.96/97
TS6.4
The Caledonian mountain belt represents a world-class example of a deeply denudated Himalayan-style orogen. The exposed crustal sections allow the study of all stages of the Wilson cycle and may contribute to our understanding of many fundamental processes in Earth Sciences, including (1) continental-rifting, break-up and ocean formation, (2) subduction plus arc-continent and continental collisions, (3) marginal basin formation, (4) deep crustal architecture of orogens, (5) (U)HP metamorphism, (6) orogenic wedge formation and dynamics, (7) the formation and evolution of crustal-scale shear zones, (8) fluid-rock interactions, (9) ductile and brittle deformation mechanisms, and (10) the dynamics of late- to post-orogenic extension and deep crustal exhumation.
This session aims to bring together scientists studying rocks and geological processes from all stages of the Caledonian Wilson cycle, i.e. from rifting to collision and post-orogenic extension, and welcomes sedimentological, petrological, geochemical, geochronological, geophysical, structural, and modelling contributions that help to improve our understanding of the Caledonides and mountain belts in general. Contributions related to the ICDP drilling project Collisional Orogeny in the Scandinavian Caledonides (COSC) are especially welcome.
Orals
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Fri, 28 Apr, 16:15–18:00 (CEST)
Room K1
Fri, 16:15
Fri, 10:45
Fri, 10:45
TS3.10
The Eastern Mediterranean is an actively deforming region where three major tectonic plates interact: the African, the Arabian and the Eurasian plates. The Cenozoic geodynamic framework of the Eastern Mediterranean region consists of subduction, collision, strike-slip kinematics, extrusion of crustal blocks and slab deformation.
This session focuses on three aspects of the Eastern Mediterranean geodynamics:
(1) Which geodynamic mechanisms define the key active structures and how do they operate?
(2) How is surface deformation being accommodated over a range of temporal and spatial scales? How individual earthquakes accrue on faults to account for their long-term kinematics? Which is the impact of deep-seated processes on surface deformation?
(3) How did the geodynamic evolution through the Cenozoic lead to present day tectonic deformation?
We welcome contributions from a wide range of disciplines including, but not limited to, neotectonics, seismology, tectonic geodesy (e.g. GNSS, InSAR), paleoseismology, tectonic geomorphology, remote sensing, structural geology, and geodynamic modeling.
We strongly encourage the contribution of early career researchers.
Orals
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Fri, 28 Apr, 08:30–11:55 (CEST)
Room K1
Fri, 08:30
Thu, 16:15
Thu, 16:15
SM5.4
We invite contributions that address the present and past structure and dynamics of the Alpine orogens and the back-arc basins of the Mediterranean area, which in the last decades has been the target of broadband large-scale passive experiments. The TopoIberia-Iberarray project, carried out in the 2000s in the Iberian Peninsula, is a successful example of the scientific progress that these experiments allow. More recently, the international AlpArray mission and related projects have generated a large amount of new data, not only seismic, to test the hypothesis that mantle circulation driving plates’ re-organization during collision has both immediate and long-lasting effects on the structure, motion, earthquake distribution and landscape evolution in mountain belts. Links between Earth’s surface and mantle have been forged by integrating 3D geophysical imaging of the entire crust-mantle system, with geologic observations and modelling to provide a look both backwards and forwards in time, the 4th dimension. This integrated 4D approach, initially focused on the Alps, has been expanded to the Pannonian-Carpathian region, with the ongoing PACASE experiment. A new initiative, AdriaArray, based on the deployment of the extensive AdriaArray Seismic Network, is underway to cover the Adria plate on both sides, including the Apennines and Dinarides-Hellenides, to shed light on plate-scale deformation and orogenic processes in this dynamic part of the Alpine-Mediterranean chain. This session provides an interdisciplinary platform for highlighting the newest results and open questions of the aforementioned projects, regions and themes.