| Text Description: |
Approximately 30-50’ thick flow displaying classic platy viscous flow structure where it has ramped over itself. Phenocrysts: Fine grained, holocrystalline, seriate porphyritic with a matrix of cryptocrystalline material, opaque, plagioclase and alteration. Plagioclase phenocrysts (An49) are up to 2.3 mm and rarely display oscillatory zoning. Opaque phenocrysts are up to 0.2 mm. Orthopyroxene phenocrysts are up to 0.4 mm. An altered phase is present. 91.6% matrix, 7.4% plagioclase, 0.1% opaque, 0.5% altered phase, 0.4% alteration. Trachyandesite. |