| Text Description: |
Core of block from Tanada Cinder Cone at Site 15. Fine grained, vesicular, holocrystalline, seriate porphyritic with a matrix of mesostasis, opaque, plagioclase, pyroxene? And olivine. Plagioclase phenocrysts (An47-An60) are up to 0.3 mm, mostly occur as small laths. Olivine phenocrysts are up to 0.6 mm, and occasionally have skeletal habits or have opaque inclusions. Orthopyroxene? phenocrysts may be detected in the thin section. Mode: 93% matrix, 1.5% plagioclase, 2.4% olivine, 3.1% vesicles |