| Text Description: |
Sample is from a polygonal jointed feeder dike on the west side of Goat Creek. The entire ridge is full of these dikes all running subparallel to each other. Fine grained, hypocrystalline, porphyritic with a matrix of pale brown glass, plagioclase, microlites, opaque and orthopyroxene. Plagioclase phenocrysts are up to 3.37 mm, but most are smaller laths; the largest grains are rounded. Orthopyroxene phenocrysts are up to 1.0 mm. Clinopyroxene phenocrysts are up to 0.2 mm. Opaque phenocrysts are up to 0.35 mm. |