Session programme

This session concerns about the interrelation between microstructures and geologic processes. One the one hand, microstructures (fabrics, textures, grain sizes, shapes, etc) can be used to identify or quantify, e.g., deformation, metamorphic, magmatic or diagenetic phenomena (to name a few). On the other hand, physical properties of geo-materials are governed by their microstructure, hence predicting a materials property is greatly enhanced by understanding of how certain processes result in a specific microstructure.

All these mechanisms are likely to cause modification on the rheological, elastic, and thermal properties of these rocks, providing key information on the evolution of the lithosphere.
In this session, we invite contributions from field observations, laboratory experiments, and numerical modelling that relate microstructures to rheology, strain localization or mineral reactions, that use microstructures to tackle general problems in structural, metamorphic, magmatic or economic geology as well as studies quantifying physical and mechanical properties of rocks based on their microstructural and textural properties using well established or novel methods.

The deformation energy budget describes how energy is stored and consumed within crustal systems. Energy stored as uplift against gravity, off-fault deformation and/or mineralogic changes can be released in the creation of new fractures, frictional heating along faults and/or radiated seismic energy. Innovative field measurements, numerical modeling and experimental approaches are providing new constraints on the energy budget within deforming crustal systems. The energy budget framework allows comparison of the energetic importance of diverse deformational processes operating in crustal systems. This framework enables tracking the evolution of the energy budget throughout time, and comparing energy budget partitioning in any tectonic system as individual fault segments propagate, interact and perhaps link. Moreover, the energy budget framework governs the rupture style and slip distribution during an individual earthquake, and is key in understanding multi-fault ruptures. Evidence suggests that new faults develop in order to optimize the overall efficiency of the system. Thus, constraining which processes dominate the budget in various tectonic systems and moments in time may help predict the timing and geometry of fault and rupture propagation and interaction. For this session, we encourage contributions that provide estimates of the evolving components of the energy budget using diverse methods, including numerical models, scaled physical analog experiments, deformation experiments on natural rock, and geophysical and field observations. Interdisciplinary work that combines several of these techniques are particularly encouraged.

Reactions between fluids and rocks have a fundamental impact on many of the natural and geo-engineering processes in crustal settings. Examples of such natural processes are 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.

From the Archean to the present, the dynamic evolution of the lithosphere is preserved in the metamorphic rock record. Each piece of evidence on mineral reactions, deformation and fluid-rock interaction helps to reconstruct the puzzle of lithospheric tectonics in all its complexity. Analytical and conceptual innovations in petrology, geochemistry, chronology, structural analysis and thermodynamic/thermomechanical modelling continue to improve our ability to read the metamorphic rock record and open new avenues for future development.

This session will highlight research in integrated metamorphic petrology and its application to solid earth behaviour in orogens, subduction zones and cratons throughout geological time. We welcome contributions across the breadth of this field—from petrology, (petro-)chronology, trace-element and isotope geochemistry to microstructures, modelling and geodynamics—with a focus on metamorphic and metasomatic processes that shape the lithosphere across a range of scales.

Invited speakers: Sarah Incel (University of Oslo), Richard Palin (University of Oxford) 

Public information:
We will have relatively few presentations in the 2nd slot, so we will transfer the last few of our 1st-slot presentations there (if authors are OK). This way we will have more time for further great discussions!

In the Plate Tectonics theory, Earth’s lithosphere is described as a rigid outermost shell deforming over long timescales along narrow boundaries, that play a central role in our Planet’s thermal and dynamic evolution. Understanding the modalities of strain localization in the lithosphere and its failure are therefore essential to describe the formation and evolution of plate boundaries, fault zones and other mechanical heterogeneities. This requires knowledge of localization processes at both micro- and macro-physical scales, the analysis of their dynamics over various time scales, and involves complementary inputs from geological and seismic observations, laboratory experiments and numerical and analog modeling.
We welcome multidisciplinary contributions that will collaboratively help to build a unified view on the dynamical evolution of lithospheric localization processes. Example topics include but are certainly not limited to the study of variations in lithospheric properties deduced from mineralogical, petrological or geological data, and of the implication of lithospheric anomalies on the dynamics of fault zones and the formation and evolution of plate margins in nature or in models.