TO: Tom Davies

FM: Jay Miller


JA Daily Science Report for Expedition 305, 18 January 2005.


SCIENCE UPDATE: Cores 305-U1309D-86R to 94R (429.4 to 472.6 mbsf, 80% recovery) are medium-grained olivine gabbro and coarse-grained gabbro, alternating on a scale of less than 20 cm to a few meters. Intervals of coarse-grained oxide gabbro (<1 m thick) are rare. Alteration is slight to moderate (<10% to 50%) overall, with rare, more pervasively altered intervals or patches, commonly associated with veins. Evidence of deformation continues to be rare, although a few more fractured intervals have been recovered. Magmatic foliation where present is commonly subtle (somewhat more evident in medium-grained olivine gabbro than in coarse-grained gabbro). A thin (< 50 cm) interval of diabase was recovered in the bottom of Core U1309D-94R.