| Text Description: |
Outcrop in the saddle between the Dome F and the spatter ridge at Site 4. Phenocrysts: Fine-grained, holocrystalline , seriate to glomeroporphyritic with a matrix of mesostasis, opaque and alteration. There is a xenolith? or glomeroporphyritic clump of 2.4 mm plagioclase and 0.8-0.3 mm clinopyroxene. Plagioclase phenocrysts (An27 - An53) are up to 1.7 mm and some have sieve textured intermediate zones, complex zoning, convolute zoning and resorbed rims; a few have heavily sieve textured cores. Clinopyroxene phenocrysts are up to 0.4 mm and have altered rims. Opaque phenocrysts are up to 0.2 mm. There is one grain of green amphibole with a black corona. |