Collaborative Research: The Volatile Contents of Seamount and Intra-Transform Lavas from the EPR: Deconstructing the Aggregation Process in MORB

Brown University, Providence RI

Investigators

Abstract

The degree to which chemical heterogeneity in the mantle affects the chemistry of lavas erupted on the spreading centers of the globe-encircling mid-ocean ridge is a topic of hot debate in the marine geology and geophysics community. Up until now, most work has focused on characterizing and trying to understand geochemical trends in axial lavas. This project focuses on off-axis and transform lavas from the East Pacific Rise which, due to their low magma recharge rates, should provide better indicators of undiluted mantle chemical differences. Project goals are to examine the extent to which these lavas exhibit compositions inherited directly from the mantle or from mixing during melt aggregation. Magmatic volatiles such as H2O, CO2, S, F, and Cl will be analyzed in about 200 geochemically well-characterized lavas from two different areas near the Rise. These data will be combined with geophysical data to determine the evolution of the magmas and whether it can be determined how much of the mantle composition of origin they represent. Broader impacts of the work include support of an institution in an EPSCoR state, international (Japan and France) and inter-institutional collaboration, and undergraduate training.