JA Daily Science Report for Expedition 312, 21 November 2005


LOCATION: Site 1256


SCIENCE UPDATE: After washing to bottom a core barrel was dropped and coring began at 0715 hr. Cores 172R and 173R penetrated from 1255.1 to 1265.4 mbsf at 1.9 m/hr with an average recovery of 18.4%. The rocks are microcrystalline slightly to highly altered dark gray basalts interpreted as dikes separated by a complex boundary zone. Light gray and dark green halos flank chlorite, pyrite, quartz, and laumontite veins. Core 173R contains 7 oriented pieces with splayed, crosscutting, and steeply dipping veins. One vein displays a very weak, shallowly-plunging mineral lineation and steps indicating sinistral offset. Primary domains of coarser grain size are spherical in places, but  one example is elongate and moderately dipping in Sample 173R-2 piece 1C.