Collaborative Proposal: 4-D Assessment of the Earliest Magmatism in a Continental Margin Arc

Virginia Museum Of Natural History Foundation, Martinsville VA

Investigators

Abstract

0000719 Beard 0001004 Crawford 0001102 Sinha As exotic material accretes to a continental margin by convergent tectonics, a number of important changes in conditions occurs, some of which lead to production of magma that subsequently becomes involved in the ongoing structural development of the accretion. As tonalitic plutons are commonly generated as continental margin arcs accrete, their composition provides information about the P-T-X H2O conditions of the source region, and combined with fabric and structural data, provide constraints for the transport and emplacement processes that might lead to chemical modification of magmas as they traverse and are emplaced in the crust. The project will utilize a suite of tonalitic plutons on Revillagigedo Island in southeastern Alaska that record early stages of continental arc magmatism. Results are expected to detail and track the origin, modification and tectonic interactions of these magmas in this convergent setting.