JA Daily Science Report for Expedition 312, 13 December 2005
LOCATION: Site 1256
SCIENCE UPDATE: For the first time in the history of deep ocean drilling, Expedition 312 has penetrated through an in-situ section of upper oceanic crust (lavas and dikes) into gabbros that represent a fossil magma chamber. After recovering 61 cm of basaltic dikes with a centimeter-scale gabbroic vein and dike-gabbro contact at the base of Core 213R, Core 214R came on deck at 1305 hr containing 3.33 m of gabbro and pegmatitic gabbro (62.5% recovery), from the interval 1410.9 to 1415.7 mbsf. Subsequent Core 215R penetrated to 1417.9 mbsf with 95% recovery of gabbro and we are currently continuing to recover gabbro. The entire Transocean crew is commended for their perseverance through the tough drilling conditions and hard rocks of the metamorphosed dike section to achieve this important but until now elusive scientific goal.