Petrology of the Hawaiian Islands; III, Kilauea and general petrology of Hawaii

Abstract

Washington describes and presents new chemical analyses for eight Kilauea lavas. The ancient lavas of Kilauea include olivine-free basalt, olivine basalt, and picrite-basalt. The recent lavas are olivine-free basalt, rare olivine basalt, and picrite-basalt. He summarizes the general character of the lavas of Hawaii. He criticizes the analyses published by Silvestri (1888). He mentions black glass in ejected blocks from Halemaumau. [See also Chapman, 1947.] Washington reviews the relationships between Kilauea and Mauna Loa and concludes on the basis of similarity of averages that a "connection between the volcanoes and a community of origin for their lavas is clearly indicated." [Modern study shows systematic differences in SiO2, CaO, K2O, P2O5, and TiO2, which distinguish Mauna Loa from Kilauea. With the exception of TiO2, which appears to be poorly determined (see note above), Washington's differences match those of modern analyses. He misses the distinction because, like many petrologists of his day, he chose to "lump" rather than "split." He criticizes Daly's hypothesis of limestone assimilation for the trachytes and his correlation of type of basalt with height of the vents.