Unit Affiliation: Geochemistry, Lamont-Doherty Earth Observatory (LDEO)
DESCRIPTION: The project focuses on the origin of the material that form andesites in Quaternary composite volcanoes and co-eval monogenetic volcanoes. We applied a range of trace element and isotopic tracers in order to test how much of the material is derived the mantle, and the overriding and subduciting crust, respectively.
OUTCOMES: We found evidence that the silicic compositions of the the Mexican arc volcanoes may easily dominated by the crustal material that was eroded from the forearc uplifted at the Middle American Trench. The large volumes of light crustal material subducted at the trench may rise in form of buoyant 'slab diapirs' beneath arc front depth and pass through mantle and crust to erupt as calc-alkaline andesites in the composite and monogenetic volcanoes of the Transmexican Volcanic Belt.
Collaborative Research: Marine EM Survey of Fluids in the Alaskan Megathrust