Clinkery aa

HA-15

Hand Sample: Apahanitic, vesicular, dark gray-black basalt. Olivine crystals are scattered throughout the sample and are approx. 0.05cm in diameter. Vesicles are very predominant throughout the sample and range in diameter from 0.01 cm to 1.5 cm This sample displays characteristics of rough aa texture. The surface of the rock is dark red-brown likely due to weathering.

Thin Section: Aphanitic groundmass composed of mainly glass and microcrystals of clinopyroxene. Medium size, elongated, euhederal plagioclase crystals are present that display twinning.

Sample collected January, 1969

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