An integrated geochemical and geodynamical approach to the origin of off-axis melt production at a range of mid-ocean ridge settings

点击翻译按钮获取中文摘要

Understanding how ocean crust is created and its how melts of different chemistry are created is an essential but presently poorly constrained aspect of global geochemical cycling between the mantle and crust. This research investigates the geochemical relationship between on- and off-axis volcanism at a variety of mid-ocean ridge spreading center settings to try and develop an integrated dynamic geochemical and geophysical modeling approach to better understand the interaction of mantle heterogeneities with the mid-ocean ridge system. A key component of this work will be to examine the geochemistry of four well-studied mid-ocean ridges (East Pacific Rise, Iceland, Galapagos, and the Juan de Fuca Ridge) to predict the degree and depth of melting required to produce off-axis melts and relate these predictions to physically realistic origins in the mantle. To create a more complete geochemical record of off-axis geochemical variation, samples from 20 seamounts near the East Pacific Rise will be analyzed for the radiogenis isotoes of Sr, Nd, and Pb, which are indicators of magmatic and magma differentiation processes. A major reserach goal is to develop robust one and two dimensional models to determine whether or not there are globally consistent off-axis processes that underpin mantle melting beneath mid-ocean ridges. The broader impacts of the work include developing the career of a postdoc from a group under-represented in the sciences and public outreach through a local Florida museum. Broader impacts also include international collaboration with a UK scientist, with the postdoc spending time in the collaborator's laboratory and being cross-trained in state-of the art geochemical analytical techniques and geodynamical modeling.