This session is open to any abstract submissions in the fields of Geochemistry, Mineralogy, Petrology and Volcanology which are not addressed by the programme themes.

The microstructure of igneous and metamorphic rocks are archives preserving abundant information about rock history, such as heating and cooling rates, metasomatism and fluid infiltration, timing and location of nucleation and crystal growth, crystallisation regime, and the extent, mechanisms and timing of deformation. Microstructural features achieve even greater importance when combined with geochemical data, but their potential is commonly under-recognised.
We welcome contributions covering the entire range of igneous and metamorphic petrology, which either showcase development of new microstructural analysis techniques or new applications of well-established techniques, or illustrate how microstructural interpretation adds to our understanding of rock history. We anticipate that this broadly-conceived session will trigger exciting new synergies across a wide range of microstructural studies.

The scientific program of this broad session is dedicated to Experimental Mineralogy, Petrology and Geochemistry. EGU offers an opportunity for the community of experimental geoscientists to discuss questions raised by the experimental approaches developed the wide range of geosciences. All aspects of experimental studies are welcome, including a wide spectrum of fields ranging from cosmochemistry to deep Earth studies; environmental geochemistry to applied mineralogy; chemical and physical properties of fluids, melts, glasses and minerals, low- and high-temperature processes, as well as new experimental developments. Results from in house laboratory studies as well as from large scale facilities like synchrotron experiments are welcome.
Max Wilker (max@geo.uni-potsdam.de) who is organizing the EMPG meeting in 2020 will also be co-convener of the session.

The quantification and understanding of diffusion rates and mechanisms in minerals and melts offers the unique capability to answer many geological questions that are otherwise inaccessible. In volcanology, diffusion chronometry can be used to determine magmatic ascent rates and timescales between magma recharge and eruption; in metamorphic petrology, diffusivities can be used to quantify cooling rates of orogens, or timescales of collision and exhumation. In geothermobarometry, it is important to understand diffusivities of the relevant elements to assess the potential for re-equilibration. Likewise, the ages obtained by radiometric dating methods may also be affected by diffusion of the parent or daughter isotopes. New developments in in-situ microanalytical techniques are expanding our ability to rapidly collect large amounts of high-quality data, continuously leading to new and exciting research directions.
This session will provide a forum for geoscientists from a wide range of disciplines to discuss and debate the most ‘timely’ topic of the earth sciences. We encourage contributions from petrologists, volcanologists, geochronologists and (geo)chemists working in any area related to diffusion, or where the potential of diffusion studies can be demonstrated. Contributions resulting from experiments, studies of natural samples, theoretical work or analytical developments are encouraged.

Atomic to nanoscale structures of rocks, minerals and fluids control the physical and chemical properties of the Earth. Examples of this include: (1) the link between atomistic motion of crystallographic defects through mineral grains and rheological behaviour of the Earth’s mantle, (2) the influence of nanogranular deformation on the stability of seismically active fault zones and (3) the observations that fluids confined in tiny spaces exhibit vastly different physicochemical properties than their bulk counterparts. We are at the dawn of a technological revolution that allows us to study Earth’s materials at scales down to the sub-nanometre level. Macroscopic descriptions fail to explain the behavior of Earth materials. It is only by investigating these materials at the tiniest length scales that we can begin to unravel increasingly complex processes (e.g. dissolution-precipitation, exsolution, coherency stress, fluid-rock interaction, defect motion etc.) with geological scale implications. In this session we welcome contributions that adopt a broad variety of experimental and numerical techniques as well as methods focused on resolving submicrometric to nanometric scale processes that could not be unraveled at the macroscopic scale of observation.

Processes responsible for formation and development of the early Earth (> 2500Ma) are not
well understood and strongly debated, reflecting in part the poorly preserved, altered, and
incomplete nature of the geological record from this time.
In this session we encourage the presentation of new approaches and models for the development of Earth's early crust and mantle and their methods of interaction. We encourage contributions from the study of the preserved rock archive as well as geodynamic models of crustal and mantle dynamics so as to better understand the genesis and evolution of continental crust and the stabilization of cratons.
We invite abstracts from a large range of disciplines including geodynamics, geology, geochemistry, and petrology but also studies of early atmosphere, biosphere and early life relevant to this period of Earth history.

Scientific drilling through the International Ocean Discovery Program (IODP) and the International Continental Scientific Drilling Program (ICDP) continues to provide unique opportunities to investigate the workings of the interior of our planet, Earth’s cycles, natural hazards and the distribution of subsurface microbial life. The past and current scientific drilling programs have brought major advances in many multidisciplinary fields of socio-economic relevance, such as climate and ecosystem evolution, palaeoceanography, the deep biosphere, deep crustal and tectonic processes, geodynamics and geohazards. This session invites contributions that present and/or review recent scientific results from deep Earth sampling and monitoring through ocean and continental drilling projects. Furthermore, we encourage contributions that outline perspectives and visions for future drilling projects, in particular projects using a multi-platform approach.

Geoscience witnessed a flurry of major breakthroughs in the 19th and 20th century, leading to major shifts in our understanding of the Earth system. Such breakthroughs included new concepts, such as plate tectonics and sequence stratigraphy, and new techniques, like radiometric dating and remote sensing. However, the pace of these discoveries has declined, raising the question of whether we have now made all of the key geoscience breakthroughs. Put another way, have we reached “Peak Geoscience” and are we now in a time of synthesis, incremental development and consolidation? Or are there new breakthroughs on the horizon? If so what will these developments be?

One key remaining challenge is the management of the inherent uncertainties in geoscience. Despite the importance of understanding uncertainty, it is often neglected by interpreters, geomodellers and experimentalists. With ever-more powerful computers and the advent of big data analytics and machine learning, our ability to quantify uncertainty in geological interpretation, models and experiments will be crucial.

This session aims to bring together those with an interest in the future of geoscience. We welcome contributions from any field of geoscience which either demonstrate a new, disruptive geoscience breakthrough or provide insights into where the next breakthrough will come. We encourage contributions associated with uncertainty in geoscience models and data, machine learning or big data analytics.