Collaborative Research: The Leading Edge of the Galapagos Hotspot, A New Window into the Mantle

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Recommended project is for an integrated marine field and laboratory investigation of the western end of the Galapagos archipelago, with a focus on studying lavas from the submarine western flanks of Fernandina and Cerro Azul volcanoes after mapping them with camera tows and multibeam and side scan sonar. The goal is to define and then sample volcanic products from the leading edge of Galapagos plume, with associated, extensive geochemical and petrological studies that will help define the nature of the Galapagos plume. These samples will be used to test whether magma chemistry from leading-edge plume volcanism indeed best reflects the chemistry of the plume mantle source, whether high 3He/4He does indeed reflect undegassed, deep mantle sources, and also to test whether the unique horseshoe-shaped pattern of Galapagos geochemical variation is due to mantle zonation or is instead related to other geologic processes. The field mapping will determine whether there is a new submarine volcano westward of Fernandina that represents the actual plume leading edge (such as represented by Loihi in the Hawaiian plume volcanism), as suggested by seismic data. This work, on the leading edge of a weak plume, will complement similar studies done at Hawaii, a strong plume, in testing models of plume volcanism and origin.***