Collaborative Research: Crust-Mantle Interactions at an Oblique Arc-Continent Collision Zone: The SE Caribbean Plate Boundary

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0607529ChristesonThis award will support a two year extension of a currently funded CD project (BOLIVAR) which is investigating the processes of continental accretion in the Caribbean. Specifically, the project is investigating how arcs accrete to the northern edge of south America using various geologic (mapping, structure), geochemical (Ar-Ar and U-Pb Geochronology), and seismic (active MCS with onshore/offshore recording using OBS instruments, passive array) techniques. There is also a geodynamic modeling study that, very innovatively, includes the dynamics of crust-mantle interaction. The overall goal of the project is to understand further the geometry and chronology of a world class, arc-continent accretion event. Seismic/geological cross-sections are being derived for several transects across the orogen at different ages of collision. The group of investigators includes highly capable seismologists in both active and passive seismology, as well as geologists familiar with the orogenic developments on land. The cooperation with Venezuelan scientists and students is excellent. In Venezuela, BOLIVAR has a formal multi-year counterpart, GEODINOS, funded by the Venezuelan government seismological organization FUNVISIS. With FUNVISIS, the PIs have completed a successful data acquisition effort consisting of active and passive land-marine seismic experiments, and numerous geologic/geochemical studies on the Venezuelan mainland and in the Leeward Antilles archipelago. Their study area is about the size of California and its continental margin, an area greater than 600,000 km 2 , and has an equally complex Late Mesozoic-Cenozoic history.