The 19-nmi voyage to Site 1087 was accomplished at an average speed of 12.6 kt. The vessel approached the Global Positioning System coordinates of the site, and a beacon was deployed at 0210 hr on 3 October. Hole 1087A was spudded with the APC at 0600 hr, and the seafloor depth was estimated from the recovery of the first core at 1371.6 meters below sea level (mbsl). APC coring advanced without incident to 255.2 mbsf (Table 1; also see expanded coring summary table on CD-ROM, back pocket, this volume), which was considered refusal depth for piston coring, with 98.9% recovery. Cores were oriented starting with Core 175-1087A-3H. Adara heat-flow measurements were taken at 46.2 mbsf (5H), 65.2 mbsf (7H), 93.7 mbsf (10H), and 122.2 mbsf (13H). The drill string was pulled out of the hole with the bit clearing the seafloor at 2225 hr on 3 October, thereby ending operations at Hole 1087A.
The vessel was offset 30 m to the south, and Hole 1087B was spudded with the APC at 2317 hr. The recovery of the first core established the seafloor depth at 1371.8 mbsl. APC coring advanced without incident to 72.5 mbsf, with 103.4% recovery (Table 1). Cores were oriented starting with Core 175-1087B-3H. The bit was pulled out of the hole and cleared the seafloor at 0340 hr on 4 October, thereby ending Hole 1087B.
Hole 1087C was spudded with the APC at 0425 hr. The recovery of the first core established the seafloor depth at 1376.2 mbsl. Piston coring advanced to refusal at 248.6 mbsf (Table 1). Cores were oriented starting with Core 175-1087C-4H. The hole was extended with the extended core barrel (XCB) to 491.9 mbsf, with 91.8% recovery.
In preparation for logging, an aluminum go-devil was dropped to ensure the opening of the lockable float valve. After the hole was flushed with a high-viscosity mud treatment, the drill string was pulled back to 442.8 mbsf, where the top drive was set back. The drill string was then placed at the logging depth of 85.8 mbsf. Logging operations began at 1930 hr on 5 October. The initial log was conducted with the seismostratigraphic suite (25.8 m long). This suite was made up of the spectral gamma-ray (NGT), long-spacing sonic (LSS), phasor dual-induction (DIT), and Lamont-Doherty high-resolution temperature (TLT) sondes. This tool string was deployed in the pipe at 2015 hr and logged the hole down to and then up from 487.1 mbsf.
While attempting to recover the logging tool string, the instrument hung up ~5 m inside the bit. Maximum overpull on the logging line was 1200 lbs. The logging tool string was eventually freed from the bit by pumping. The logging winch operator tried to work the tool into the drill string again by incrementally pulling on the logging line up to a maximum of 4000 lbs head tension. This time, the tool string became totally stuck in the bit and was unable to be worked up or down. Attempts to retrieve the logging tool string with the logging cable were given up, and the Kinley cutter and crimper tools were prepared. The Kinley crimper was dropped and followed by a Kinley hammer. The drill string was pulled out of the hole, with the bit clearing the plane of the rotary table at 0715 hr. The logging tool string was not recovered.
The vessel was offset 30 m to the south, and Hole 1087D was spudded at 1030 hr on 6 October. After drilling to 72.5 mbsf, piston coring was initiated. APC coring proceeded to 177.0 mbsf (Table 1), which required the use of the last full-sized liner. A sole XCB core was then taken from 177.0 to 186.6 mbsf and recovered 9.88 m (102.9%). This core used the last liner of any length whatsoever on the vessel. The hole was then completed to a depth of 201.3 mbsf with two piston cores, which were obtained without liners, and recovered 100%. The total piston cored interval was 119.2 mbsf, with 121.04 m recovered (101.5%). The last core gave a total leg recovery of 8003.23 m. The drill string was then pulled out of the hole, with the bit clearing the seafloor at 2140 hr. The beacon was recovered at 2215 hr. The bit was at the rotary table at 0145 hr on 7 October. At 0700 hr on 7 October, the vessel departed the last site of Leg 175.