This project is for a geologic and petrologic investigation of the Yunaska Volcanic Center. Yunaska has been chosen because it: 1) sits on unextended crust of the arc massif; 2) has numerous unusual geomorphic characteristics; 3) displays evidence for both young and old vent areas; 4) is spatially removed from the Amlia Fracture Zone; and 5) occurs in a geologically unknown part of the ALeutian arc. The PIs plan to map and sample extensively the island during three field seasons. Using this information as well as K-Ar dating, they will reconstruct the geologic history of the island. Analytical work will characterize the volcanic rocks petrographically as well as geochemically. This detailed characterization of Yunaska should improve materially our knowledge of the Aleutian arc as well as the petrologic processes responsible for its volcanic products. Ultimately, such information should enhance our understanding of subduction magmatism in general.
