| Text Description: |
Massive flow from the top of the wall-like andesite outcrop that overlies silicic material from Dome A at Site 3. Fine-grained, vesicular, diktytaxitic, hypocrystalline, intersertal, intergranular, seriate porphyritic with a matrix of brown glass, mesostasis, opaque, feldspar, orthopyroxene and clinopyroxene. Plagioclase phenocrysts (An30 - An57) are up to 1.05 mm and some have sieve textured cores or intermediate zones, complex zoning, and a few have orthopyroxene inclusions. Orthopyroxene phenocrysts are up to 1.35 mm and some have clinopyroxene rims and/or feldspar inclusions. Clinopyroxene phenocrysts are up to 0.2 mm. 52.7% matrix, 35.5% plagioclase, 8.4% orthopyroxene, 3.4% vesicles. |