| Text Description: |
A 10-20’ thick flow that is the top exposure in unit nA1 at Site 4. Fine-grained, holocrystalline, intergranular, seriate porphyritic with a matrix of mesostasis, opaque and greenish alteration. Plagioclase phenocrysts (An39 - An58) are up to 2.1 mm and display sieve textured cores and intermediate zones, complex zoning, and rarely convolute zoning. Orthopyroxene phenocrysts are up to 1.1 mm and have clinopyroxene rims and rarely have opaque inclusions. 52.9% matrix, 32.4% plagioclase, 0.3% clinopyroxene, 7.5% orthopyroxene, 6.9% alteration. |