| Text Description: |
First good outcrop above the Chisana Volcanics at Site 9. The flow is at least 25' thick. Fine-grained, holocrystalline, intergranular, seriate to glomeroporphyritic with a matrix of mesostasis, opaque, plagioclase, clinopyroxene and minor alteration. Plagioclase phenocrysts (An39-An62) are up to 2.1 mm, and frequently display sieved textured cores, and occasionally poikilitic pyroxene and/or opaque inclusions or resorption embayments. Olivine phenocrysts are up to 0.5 mm and are frequently rimmed by small pyroxene and plagioclase crystals. Orthopyroxene phenocrysts are up to 0.62 mm and some have clinopyroxene rims and/or opaque inclusions. Clinopyroxene phenocrysts are up to 0.7 mm. Opaque phenocrysts are up to 0.1 mm. Mode: 68.5% matrix, 24.5% plagioclase, 2.3% olivine, 2.5% clinopyroxene, 1.7% orthopyroxene, 0.2% alteration, 0.3% vesicles. |