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GMPV8.5 | From subduction to eruption: Understanding elemental cycles and magmatic systems in intra-oceanic arc-backarc systems
From subduction to eruption: Understanding elemental cycles and magmatic systems in intra-oceanic arc-backarc systems
Convener: Christoph Beier | Co-conveners: Isobel YeoECSECS, Philipp Brandl, Marta Ribo GeneECSECS
The fastest plate motion rates on Earth are observed at intra-oceanic subduction zone systems, especially in the Western Pacific. Rapid slab rollback creates extensional forces in the overlying arc, resulting in arc splitting, rifting, and eventually backarc spreading. Thus, these systems represent rare occasions where all three types of plate boundaries can be studied in one geological setting. Intra-oceanic arc-backarc systems are characterized by relatively thin crust compared to their continental counterparts. Melts ascending and eventually focusing into volcanic systems are thus interacting with a thick crustal filter, and have a high potential to preserve the geochemical signals inherited from the subducting slab and overlying mantle wedge. These melts will undergo magmatic differentiation and stagnation in the crust, before being stored in complicated volcanic plumbing systems, from which it may, eventually be erupted. The massive eruption of the Hunga volcano in Tonga in early 2022 is only one such powerful example indicating that these systems are insufficiently studied, primarily because the largest areas of intra-oceanic arc-backarc systems are submarine and therefore hard to access. The volcanic and hydrothermal processes, which govern hazards and resources in these regions, are controlled by a complicated interaction of these processes.
In this session, we target contributions dealing with the geological, physical, and chemical processes that drive spatial and temporal elemental cycles and magma evolution in intra-oceanic arc-backarc systems. We mainly focus on multi-disciplinary studies integrating geophysical, petrological, and volcanological data to better understand the tectonic and magmatic drivers of volcanic eruptions in arc-backarc systems.