| Text Description: |
Massive block from base of brecciated material at Site 12. Fine grained, hypocrystalline, intersertal, seriate porphyritic with a matrix of brown glass, mesostasis, opaque, and plagioclase. Plagioclase phenocrysts (An28-An57) are up to 5.5 mm in length and commonly have sieve textured cores, normal or oscillatory zoning, and rarely display olivine inclusions or resorption embayments. Olivine phenocrysts are up to 1 mm and a few have resorption embayments or opaque inclusions. Orthopyroxene phenocrysts are up to 0.6 mm. |