PIRE: ExTerra Field Institute and Research Endeavo

Non-technical abstract OIA1545903 'PIRE: ExTerra Field Institute and Research Endeavor (E-FIRE)'

Subduction is a fundamental Earth process in which two tectonic plates converge, forcing one plate deep into Earth's mantle. Subduction produces most of Earth's deadliest earthquakes and volcanic eruptions, for example around the Pacific Ocean rim's 'Ring of Fire'. ExTerra (Exhumed Terranes) is a broad US geosciences consortium that investigates rocks exhumed from fossil subduction zones - rocks whose evolution uniquely illuminates processes otherwise obscured beneath the surface of active subduction zones. ExTerra will partner with our sister European organization ZIP (Zooming In between Plates) using novel field institutes to promote collaborative research among US and European researchers focused on subduction zone processes. The E-FIRE project develops a new paradigm for collaborative geological research that focuses on collaborative field work to collect materials held communally, augmented by broad interactions through workshops and student exchanges. Each researcher contributes a different analytical expertise to a combined effort aimed at transforming our understanding of active subduction zone processes. International partnership is critical because European researchers actively investigating the geology of each field area will provide foundational field knowledge of the region and actively participate in analysis and interpretation with US researchers. The project will integrate students and post-doctoral scholars (Early-Stage Researchers, ESRs) into a developing international network of scientists, help train ESRs in research and education, and provide a model for future geoscience collaborations across disciplines. E-FIRE will also create a uniquely valuable sample archive that will be made accessible to the greater research community along with the data generated by this project.

Technical abstract OIA1545903 'PIRE: ExTerra Field Institute and Research Endeavor (E-FIRE)'

The purpose of E-FIRE is to trace the cycle of rocks and fluids through the subduction process, as recorded in Earth's premier example of a fossil subduction zone - the Western Alps, Europe. The processes by which rocks, melts, and aqueous fluids exchange and interact among different physical components of the subduction system control all aspects of subduction. These processes occur deep within subduction zones, and a full understanding of these deep processes is a challenge both for investigations using remote geophysical methods and for scientists investigating active volcanoes above subduction zones. Investigations of exhumed rocks from within the subduction zone provide a unique, direct source of information regarding these processes. Specific research questions that we will explore include: 1) How do elements cycle among crust, mantle and Earth's surface? 2) What are the depths, temperatures, and timescales of rock transformation and fluid release within subduction zones? and 3) What is the mechanical behavior of materials within subduction zones? The proposed projects will adopt a variety of approaches to address these questions, including mineralogical and petrological analysis; textural characterization; geochemical analysis of major elements, trace-elements (e.g. HFSE, REE, etc.), stable isotopes (e.g. δ37Cl, δ13C), and radiogenic isotopes (U-Pb and Sm-Nd); and thermodynamic modeling. E-FIRE will implement a series of Field Institutes and Workshops aimed at developing an international, interdisciplinary network of scientists focused on subduction zone processes. These activities, along with student exchanges among participating institutions, will train early stage researchers (ESRs: students and post-doctoral scholars) in research, communication, and collaborative practice, ultimately developing a career-long collaborative network. Samples and data collected during E-FIRE will be archived and made available to the greater research community.