| Text Description: |
Flows with thick rubble zones and thin massive zones. The package is a couple of hundred feet thick and overlies silicic material in Finger Creek. The sample is from the top flow and is cut by a dike (94SJP50B). Fine-grained, holocrystalline, weakly pilotaxitic, intersertal, locally intergranular, seriate porphyritic with a matrix of mesostasis, opaque, feldspar, clinopyroxene, orthopyroxene, yellowish altered patches, and calcite alteration. Plagioclase phenocrysts (An26-An55) are up to 1.1 mm, display complex zoning, and a few grains have sieve textured intermediate zones. Orthopyroxene phenocrysts are up to 0.6 mm and have clinopyroxene rims. Clinopyroxene phenocrysts are up to 0.35 mm. |