| Text Description: |
A 10-15’ thick flow at Site 4. Fine-grained, holocrystalline, locally intergranular, seriate porphyritic with a matrix of mesostasis, opaque, clinopyroxene and alteration. Plagioclase phenocrysts (An35 - An48) are up to 0.85 mm and some have sieve textured cores or intermediate zones, complex zoning, and occasional resorption embayments or tooth-like overgrowths. Orthopyroxene phenocrysts are up to 0.6 mm and some have clinopyroxene rims; grains tend to include small plagioclase laths along rim. Clinopyroxene phenocrysts are up to 0.1 mm. |