JA Daily Science Report for Expedition 309, 20 July 2005


LOCATION: Site 1256


SCIENCE UPDATE: Cores 1256D-78R to 81R were cored from 763.5 to 792.2 mbsf with recovery of 9.31 m (32%). Rate of penetration varies from 1 to 1.5 m/hr. Cores 77R to 79R are aphyric to sparsely phyric, cryptocrystalline to microcrystalline, slightly altered dark grey basalt sheet flows separated by chilled margins. Phenocryst phases are olivine, plagioclase, and clinopyroxene in order of increasing abundance. Evenly distributed moderate fracturing is common along with 0.1 mm to 1 mm irregular veins filled with saponite, iron-oxyhydroxide, celadonite and minor silica and sulfides. Some mixed black and brown and brown halos occur adjacent to fractures.