TO: Tom Davies
FM: Jay Miller
JA Daily Science Report for Expedition 305, 22 January 2005.
SCIENCE UPDATE: Cores 305-U1309D-116R to -124R (573.4 to 616.6 mbsf, 83% recovery) is varitextured gabbro, olivine-bearing gabbro, and oxide gabbro. Grain size is predominantly coarse, with several intervals of medium- to coarse-grained, commonly olivine-bearing gabbro. Oxide gabbro intervals range from thin (few centimeter) seams to 1 m thick bands with several modal percent oxide. Alteration is variable, but generally 15-30%. Rare thin intervals (<20 cm thick) show evidence of deformation, but cystal-plastic fabric is, for the most part, subtle. Contacts between units occur as both sharp and gradational transitions.