RUI: An Investigation of the Mauna Kea Magma Plumbing System: Insights From Mineral Composition From the HSDP Core

California State University-Fresno Foundation, Fresno CA

Investigators

Abstract

Putirka EAR-0337345 Phenocrysts provide an archive of the pressures and temperatures at which magmas stagnate and evolve and the liquids from which they crystallized. Phenocryst compositions can thus be used to create a cross section of a magma conduit system, and thereby test hypotheses regarding magma transport and liquid evolution. Clinopyroxene phenocrysts, in particular, are extremely useful in deciphering, for instance, if the solubility of jadeite is sensitive to pressure. The funds provided by this proposal will support a two-year study of clinopyroxene compositions from the Hawaii Scientific Drilling Project (HSDP2), with the goal of understanding magma transport and liquid evolution at Mauna Kea, Hawaii. Since the HSDP core provides a unique time-integrated view of the Mauna Kea magma plumbing system, the PI and his students will examine whether the conditions of crystallization exhibit temporal patterns. Not only will this view potentially shed light on the evolution of a magma conduit system, but phenocryst compositions might also allow a test of the extent to which the upwelling plume is compositionally or thermally zoned. Both undergraduate and graduate students at California State University, Fresno, will perform much of the data analysis for this project. The role of undergraduates is very important, as experience has shown that students are particularly motivated when they are part of a larger research program. For the present study, a graduate and several undergraduate students will take the lead in the collection and analysis of the mineral chemistry data. The graduate student will be assigned the somewhat more challenging task of reconstructing liquid compositions, while a team of undergraduates will conduct the estimation of P-T conditions. All students will share in the construction of a model for the Mauna Kea magma plumbing system and with the oral presentation and publication efforts.