| Text Description: |
Lowest-most outcrop on west side of the creek. The flow is 15-20' thick and dips N60E, 45W at Site 15. The flow is overlain by 94SJP3 and underlain by yellow lahar. Fine grained, holocrystalline, porphyritic with a matrix of plagioclase (An36-An40), clinopyroxene, opaque, and alteration. Clay balls are present. Plagioclase phenocrysts (An37-An61) are up to 1.5 mm and sometimes occur in glomeroporphyritic clots; most are not zoned; the larger grains have normal zoning or rarely oscillatory zoning. Clinopyroxene phenocrysts are up to 0.5 mm. An altered phase, probably olivine, is also present. Mode: 75.5% matrix, 8.2% plagioclase, 0.2% clinopyroxene, 16.1% alteration. |