This proposal is for geologic and geochemical investigations into the origin of alkaline and peralkaline magmatism. The PIs propose to extend their chemical investigations of volcanic rocks from the islands and from submarine topographic highs in the region to include detailed trace element analyses by INAA and isotopic analyses of O and Pb. The PIs will also continue Ar geochronology of the Socorro Island in order to quantify thermochemical fluxes to the island. By establishing the eruptive history and effects of contamination, it will be possible to more quantitatively document the nature and thermal evolution of magmatic processes that lead to the production of salic peralkaline magmas.
