TO: Tom Davies

FM: Jay Miller


JA Daily Science Report for Expedition 305, 15 February 2005.


SCIENCE UPDATE: Cores 305-U1309D-246R to -252R (1182.3 to 1215.9 mbsf, 74% recovery) start with a 1-m-thick, coarse-grained oxide gabbro yielding below to coarse-grained olivine gabbro. Although no lower contact was recovered, the next core starts a several m thick interval of olivine-rich troctolite (80-90% olivine with interstitial plagioclase) with intrusions of olivine-bearing gabbro. Below 1197 mbsf, through the rest of the cored interval, the recovered rocks are gabbroic, starting in medium-grained olivine-bearing gabbro, transitioning through a few m of troctolitic gabbro to gabbro. Overall, recovery for the day included 5% oxide gabbro, 25% gabbro, 15% olivine gabbro, 25% troctolitic gabbro, and 30% olivine-rich troctolite.