In this project the PIs will extend their geochemical modeling work through analysis of a large suite of basalts from Atlantic, Indian, and Pacific oceans. They argue that the existing data are few and often not useful for answering many important questions that have been raised: for example, can it be possible to map domains in the upper mantle for their trace element ratio characteristics? It is not even clear as to how much of the differences seen in the existing data are due to interlaboratory differences. The PIs argue that incompatible trace elements and isotopic ratios are most helpful in comparing different oceanic basalts. They are developing ICP-MS techniques to analyze the basalts from the oceans and ophiolites for strongly incompatible trace elements. Their objective is to develop models for source mantle heterogeneities, thermal structure and convection in the upper oceanic mantle.
