| Text Description: |
Approximately 10’ thick, sheety dike, trending N135°E and cutting through 94SJP74B. The dike appears to continue to the top of South Pass. Fine grained, vesicular, hypocrystalline, intergranular, glomeroporphyritic with a matrix of pale brown glass, opaque, orthopyroxene and plagioclase. Plagioclase phenocrysts (An40 - An61) are up to 1.75 mm; the smaller grains are laths with normal zoning; the larger grains have complex oscillatory zoning, resorption embayments and sieve textured zones. Orthopyroxene phenocrysts are up to 1.5 mm and some have clinopyroxene rims, occasional sieve textured zones and/or opaque inclusions. Clinopyroxene phenocrysts are up to 0.9 mm. Olivine phenocrysts are up to 0.65 and are altered. Opaque phenocrysts are up to 0.1 mm. |