Daily Report for IODP Expedition 311, October 15, 2005
LOCATION: Site U1328 (CAS-06A)
SCIENCE UPDATE: With the FMS-sonic logging run completed at 02:45 hr, we switched over to VSP operations. The marine mammal watch began at 07:30 hr, followed by the 30 minute ramp up of the GI gun at 08:30 hr. The start of the VSP log run began at 09:00 hr with the first clamping position at 286 mbsf. The VSP was run successfully to the shallowest clamping position of 106 mbsf. Shallower positions were too noisy due to interference with the drill pipe, which had been set back to 76 mbsf. VSP operations were completed at 14:00 hr and the GI gun was pulled back on deck and the marine mammal observers left station. Over the 180 m interval surveyed, we lost only two clamping positions due to bad hole conditions. Preliminary interpretation of the observed VSP derived travel times yielded a surprisingly uniform P-wave velocity of ~1640 m/s. After securing the logging tools, we moved 35 m to Hole U1328D for a high-resolution combined microbiology and geochemistry study of the sulfate/methane interface. The first two deployments of the APC resulted in bent core barrels and we switched to the XCB coring system. Two XCB cores were recovered followed by deployment of the FPC pressure core at 14 mbsf, which did not recover core.