Contributions to the petrography of the Sandwich Islands

Abstract

Dana describes specimens of lava, including lava stalactites, from Mauna Loa and from Kilauea, collected by J.D. Dana and E.S. Baker. The lavas of Mokuaweoweo and Kilauea are found to be strikingly similar. Samples from Mokuaweoweo include clinkstone-like basalt, chrysolitic basalt, lavas with minute feldspar and augite crystals in their cavities, and others. He describes elongated (skeletal) olivine crystals and dendritic growths of augite, illustrated by excellent drawings. Glass is found to contain both microlites and crystallites. The lava stalactites, also well-photographed, are thought to have been formed by a process of "aqueo-fusion" by highly heated water vapor. Dana also describes 1790 ejecta, including one block with apatite-bearing glass in vesicles, and lava from Haleakala on Maui and from Oahu.