Volatiles and Fluids in Subduction Zones

C4 in context to the overall objectives of the SFB 574

Project C4 focuses on both major objectives of the SFB, on the mechanisms and assessment of volcanic hazards and on the volcanic fluxes of volatiles, particularly those affecting climate and atmosphere composition. The successful collaboration between C4 and C2 in evaluating the volatile fluxes at the CAVA will be continued in phase III. Mafic rock compositions investigated by C2 provide potential starting points for the differentiation paths of the more evolved rocks investigated by C4. On the other hand, differentiation trends identified by C4 will help to distinguish mantle from crustal signatures in C2 samples. Results from both projects will add to the whole volatile budget of the Andean volcanoes jointly studied. The elemental fluxes from both Central America and Chile provide data to verify the numerical transport-reaction modeling done in C5. Geophysical studies of projects A5 and A2 at volcanic clusters I and II will reveal the structure of the crust and the mechanics of the regional tectonic system which we can compare with our volcanological/petrological results to identify their effects on the volcano-magma systems. Project C4 will provide time series data on large eruptions - first from Central America, later from Chile - such as age, discharge rate, minimum duration, column height, total volatile discharge that serve as input for the climate modeling in C5. Our successful collaboration with A- and B-projects, by which we have dated mud mound activity and submarine landslides, will be continued with A1 and B5 via participation in the planned METEOR cruise. Our analysis of marine ash layers is again aimed at correlating and dating events on the slope, and at determining the composition of subducted sediments. Together with B5, C1, and C2, C4 investigates halogen isotopes to contribute to a better understanding of how these isotopes evolve through the subduction system.