| Text Description: |
Feeder dike trending N50°E to N60°E on the west side of Goat Creek. The dike has cross-wise polygonal jointing and is similar in lithology to a flow higher up. Fine grained, hypocrystalline, pilotaxitic, porphyritic with a matrix of pale brown glass, cryptocrystalline material, opaque, feldspar and apatite?. Plagioclase phenocrysts are up to 2.5 mm and often display strong normal zoning and are rounded. Clinopyroxene phenocrysts are up to 0.55 mm. Orthopyroxene phenocrysts are up to 1.0 mm and some have resorption embayments or opaque inclusions. Opaque phenocrysts are up to 0.2 mm. 95.5% matrix, 3.4% plagioclase, 0.6% orthopyroxene, 0.2% clinopyroxene, 0.3% vesicles. |