Leg 207 officially began with the first line ashore at Bridgetown, Barbados, at 2255 hr on 11 January 2003. After two days of port call activities, the last line was released and the ship maneuvered into the harbor.
The transit to the Leg 207 operational area was uneventful, and at 0730 hr on 15 January, the ship's speed was reduced in preparation for a short seismic survey to produce a crossing line at Site 1258 (see "JOIDES Resolution Underway Geophysics (Leg 207)" in Shipboard Scientific Party ["Site Survey and Underway Geophysics"], this volume). The survey was completed by 1200 hr, and we proceeded to Site 1257. Upon arriving at the coordinates for the site, the thrusters and hydrophones were lowered, followed by deployment of a positioning beacon at 1533 hr on 15 January, which initiated operations at Site 1257.
Once the ship settled on location, an advanced piston corer (APC)/extended core barrel (XCB) bottom-hole assembly (BHA) was constructed and tripped close to the seafloor. With the bit positioned at 2955 meters below rig floor (mbrf), the first APC core recovered 2.59 m of sediment. Based on the recovery in this mudline core, the water depth was calculated to be 2961.9 mbrf (2951.0 mbsl). Beginning with Core 3H, APC cores were oriented. Core 3H also initiated the deployment of the APC temperature (APCT) tool. APC coring continued through Core 5H to 40.6 mbsf (recovery = 104%), where APC coring was terminated because excessive overpull forces (up to 140,000 lb) were required to extract the last three cores. After recovery of Core 5H, it was discovered that one of the three 10-ft APC nonmagnetic core barrel sections was bent. With no replacement nonmagnetic APC core barrels on board, a standard steel barrel assembly was placed in service and alternated with the other remaining nonmagnetic core barrels thereafter.
Coring continued with the XCB from 40.6 to 284.7 mbsf (recovery = 71.1%) and was terminated when the target depth was reached. Much of the lower part of the cored interval was penetrated at a slower than anticipated rate of ~10 m/hr. Core 21X (179.0–188.6 mbsf) recovered 1.22 m of black shale with a strong petroliferous odor, which registered 15 ppm using the handheld H2S gas detectors. The cutting shoe used to recover Core 21X was twisted and discolored from friction-induced heating and probably contributed to the strong odor from the organic-rich sediment. No similar concerns were encountered during subsequent coring.
At 0930 hr on 18 January, with the target depth reached in Hole 1257A (Table T1), coring operations ceased and the hole was prepared for logging with a 30-bbl sepiolite mud sweep and a wiper trip. The wiper trip indicated that the hole was in excellent condition, with only 1 m of fill on bottom. The hole was displaced with another 125 bbl of mud, and the bit was positioned at 82 mbsf for logging.
The first logging run was made with the triple combination (triple combo) tool string (see "Downhole Logging" for details on the individual sensors on the logging tools), which was deployed to ~284 mbsf and logged to the seafloor (the upper 60 mbsf through the pipe) in two passes. The second logging run included two passes with the Formation MicroScanner (FMS)-sonic tool string from 284 mbsf to the base of the drill string at 60 mbsf. The third and final logging run was made with the Well Seismic Tool (WST) from 284 to 60 mbsf, recording clean data at eight stations. After completion of the logging operations, the drill string was retrieved, clearing the rig floor at 2245 hr on 19 January and ending Hole 1257A.
The ship was offset 30 m southeast of Hole 1257A, and a rotary core barrel (RCB) BHA with a center bit assembly was deployed. Hole 1257B was spudded at 0630 hr on 19 January and drilled to 40 mbsf. The center bit was retrieved, an RCB core barrel deployed, and coring advanced to 227.3 mbsf, taking 27 cores (recovery = 62.1%) (Table T1). The hole was terminated when the depth objectives were reached. After filling the hole with sepiolite mud, the drill string was pulled out of the hole, ending Hole 1257B at 1320 hr on 21 January.
The ship was offset another 30 m to the southeast, and Hole 1257C was spudded with the center bit in place at 1415 hr on 21 January. The hole was advanced to 82 mbsf, and the center bit was retrieved. With the RCB, coring deepened the hole to 235.9 mbsf, taking 16 cores (recovery = 62.8%) (Table T1). With the depth objective met, the hole was filled with sepiolite mud and the drill string was retracted, clearing the rotary table at 1530 hr on 22 January and ending operations at Site 1257. After recovery of the beacon and retraction of the thrusters and hydrophones, the ship began the transit to Site 1258.