We assembled a BHA similar to that used at the previous sites and ran the bit to the seafloor. Hole 1006A was initiated at 1355 hr on 15 March. The water depth was 657.9 mbsl based on recovery of the mudline core. Continuous APC cores were cut to 273.1 mbsf with 97.4% recovery. Cores 1006A-3H-29H were oriented. Adara temperature tool heat-flow measurements were taken from Core 3H-11H, and every third APC core thereafter. Core 29H was required 80,000 lb, therefore, APC coring was terminated. XCB Cores 30X to 77X were cut from 273.1 to 717.3 mbsf with 82.5% recovery. WSTP temperature probes were deployed after Cores 32X, 35X, 38X, and 43X. Core jamming in the core catcher or core liner was observed in 14 of the last 19 cores. Coring operations were terminated at 717.3 mbsf when the objectives for this hole were achieved. A standard conditioning trip was made and the drill string was positioned at 104 mbsf for logging. The following logging runs were performed to total depth (717 mbsf) without incident: DIT/Sonic, IPLT/GR, FMS, and a VSP experiment. The bit cleared the seafloor at 0940 hr on 19 March.
The ship was moved 20 m west, and Hole 1006B was spudded at 1045 hr on 19 March. The water depth was 657.5 mbsl based on recovery of the mudline core. APC Cores 1006B-1H to 19H were cut from 0 to 176.5 mbsf with 103.2% recovery. Cores were oriented from Core 3H. The bit cleared the seafloor at 1955 hr on 19 March.
Hole 1006C was spudded to acquire a single, oriented mudline core in an attempt to obtain sediments recording the Blake paleomagnetic event that appeared to be present in the top few meters of the unoriented, first core of each of the previous two holes. The ship was moved 20 m west, and Hole 1006C was initiated at 2045 hr on 19 March. The water depth was 658.4 mbsl based on recovery of the core. APC Core 1006C-1H was cut from 0 to 6.6 mbsf with 99% recovery; however, the core liner was badly splintered. Coral debris was found in the shoe and is probably responsible for what appears to be a liner impact failure. Consequently, the hole was terminated.
The ship was not moved, and another single, oriented mudline core was attempted. Hole 1006D (Site BT-5) was spudded at 2200 hr on 19 March. The water depth was 668.9 mbsl based on recovery of the core. APC Core 1006C-1H was cut from 0 to 7.6 mbsf with 100% recovery. The drill pipe was pulled and secured at 0113 hr on 20 March.
Site 1007 Operations Report
166 Table of Contents