| Text Description: |
Sample is from a flow at Site 5 with a vesicular top and dipping NNW. Fine-grained, holocrystalline, porphyritic with a matrix of mesostasis, opaque and plagioclase. There is a 2 mm inclusion of brown glass, feldspar and microlites surrounded by a 0.3 mm wide reaction corona of 0.1-0.2 mm clinopyroxene. Plagioclase phenocrysts (An45 - An61) have two populations: less abundant 1.0-0.3 mm, with sieve textured zones and irregular shape; more abundant 0.3-0.05 mm laths. Olivine phenocrysts are up to 1.65 mm and some have skeletal habits, some have opaque inclusions. One clinopyroxene grain, 0.15 mm, is observed. 82.3% matrix, 10.4% plagioclase, 5.9% olivine, 1.1% clinopyroxene, 0.3% vesicles. |