Ankaramites are dark porphyritic basalts that contain abundant pyroxene and olivine phenocrysts. Lesser amounts of biotite, and plagioclase may also be present.
Hand Sample: Aphanitic dark gray vesicular Ankaramite. Sample contains abundant vesicles ranging in size from less than 0.05cm to 0.8cm. Sample also contains numerous larger crystals with iridescent luster ranging in size from 0.1cm to 0.8cm. Phenocrysts of olivine approximately 0.2cm in diameter can also be found throughout the sample.
Thin Section: Groundmass made up of microcrystals of clinopyroxenes, glass, plagioclase. Phenocrysts of olivine and pyroxenes are present in addition to some accessory biotite grains.
Sample collected in January, 1969.
Is Part Of
Volcanic Phenomena Suite - The Hawaiian Islands of Hawaii and Oahu
Number of Thin Sections