This project is to investigate the petrogenesis of the Kolekole Volcanics, which represent the products of the last eruptive activity of the Waianae Volcano of Oahu, Hawaii. In some respects the Kolekole can be considered the rejuvenation state of the Waianae Volcano. However, unlike most rejuvenation stage volcanism in Hawaii, the Kolekole appears to be closely related temporally and chemically to earlier phases of Waianae activity. The PIs will investigate this relationship through studies of the field relations, petrology and geochemistry, and radiometric dating of the Kolekole and underlying lavas. In particular they propose to test: 1) whether or not Kolekole Volcanics could have been derived from similar sources as the shield and post-shield Waianae Volcanics, and by what sort of melting processes, and 2) the nature and depth of fractionation affecting Kolekole magmas, principally by modeling Kolekole lava variations using mineral mocpositions of included phenocrysts, xenocrysts and xenoliths. Data obtained in this study will greatly increase our knowledge of Hawaiian volcanic field relations, chemistry and evolution of Hawaiian alkalic magmas. It should provide the first accurate dates of Kolekole volcanism.
