The 349-nmi transit to Site 1241 (proposed Site COC-2A) required 30.0 hr at an average speed of 11.6 kt. The 3.5-kHz precision depth recorder (PDR) was used as a final check of site characteristics by comparison to precruise survey data. The vessel was on site by 1545 hr on 20 May 2002.
The drill bit was deployed to a depth of 2033.4 meters below rig floor (mbrf), and Hole 1241A was initiated with the advanced piston corer (APC) at 2118 hr. The seafloor depth that was estimated by the amount of recovery of the first core was 2038.6 mbrf. This was 2.8 m shallower than the corrected PDR depth of 2041.4 mbrf. Piston coring penetrated to 314.2 meters below seafloor (mbsf) before it was necessary to switch to the extended core barrel (XCB) (Table T1). A total of 13 core barrels that could not be pulled with a force of 60 klb were drilled over starting with Core 22H. Piston coring in the hole was terminated when the last piston core (34H) did not achieve a full stroke of the corer.
The piston cores were oriented starting with Core 4H. Downhole temperature measurements were taken with the APC temperature (APCT) tool (Table T1). The nonmagnetic core barrel was deployed on even-numbered cores up to and including Core 22H. The APC cored 314.2 m and recovered 333.4 m (recovery = 106%).
XCB coring deepened the hole from 314.2 to 394.4 mbsf. The XCB cored 80.2 m and recovered 71.5 m, representing an average recovery of 89%. The APC/XCB cored interval was 394.4 m, and the average recovery in Hole 1241A was 103% (Table T1). The active heave compensator was online during XCB coring.
The bit was pulled free of the seafloor at 1920 hr on 22 May.
The vessel was offset 20 m west of Hole 1241A. Prior to coring in Hole 1241B, a bottom water temperature measurement was obtained with the APCT tool with the bit positioned just above the seafloor. All APCT measurements combined indicated a low thermal gradient of ~2.7°C/100 m. To obtain a stratigraphic overlap with the first hole, the bit was placed at 2036.0 mbrf and Hole 1241B was initiated with the APC at 2115 hr. The seafloor depth derived from the recovery of the first core was 2037.1 mbrf. Piston coring and two 2-m drilled intervals (84.4-86.4 and 257.4-259.4 mbsf) deepened the hole to 259.4 mbsf. Seven fully stroked core barrels were drilled over in this hole (Cores 21H through 27H). The cores were not oriented because only one Tensor orientation tool remained operational, and it was preserved for use at the last site, where magnetic declination data were likely to be important. The nonmagnetic core barrel was deployed on odd-numbered cores up to and including Core 21H. The piston cored interval was 257.4 m with 258.43 m recovered (recovery = 101.2%).
Five XCB cores deepened the hole from 257.4 to 307.6 mbsf. The 87.4-m interval from 307.6 mbsf to the basement contact at 395.0 mbsf was drilled in preparation for logging. The XCB cored 48.2 m and recovered 43.8 m (recovery = 91%). The total cored interval was 303.6 m with an average recovery of 100% (Table T1).
To prepare the hole for logging, it was flushed with 30 bbl of sepiolite mud. The hole was then displaced with 182 bbl of 8.9-lb/gal sepiolite mud, and the bit was placed at the logging depth of 97.45 mbsf. The triple combination (triple combo) tool string with the Lamont-Doherty Earth Observatory (LDEO) Multi-Sensor Spectral Gamma Ray Tool (MGT) on top was deployed first, followed by the Formation MicroScanner (FMS)-sonic tool string. One pass with the triple combo was conducted from total depth (395 mbsf) to the mudline, followed by one full pass from 395 mbsf to the bit with the MGT. Two subsequent passes with the FMS-sonic tool string also reached the bottom of the hole. The diameter of the hole ranged from 10.5 to 13.5 in, providing for good log quality.
Logging operations in Hole 1241B were completed by 1400 hr on 24 May. The bit was pulled free of the seafloor at 1510 hr on 24 May.
The vessel was offset 20 m west of Hole 1241B, and Hole 1241C was initiated with the APC at 1612 hr on 24 May with the bit positioned at 2039.0 mbrf. The seafloor depth calculated from the recovery of the mudline core was 2038.5 mbrf. Piston coring combined with drilling deepened the hole to 143.5 mbsf. Four intervals (6.0-26.0, 41-47.5, 104.5-112.0, and 131.0-134.0 mbsf), a total of 42.5 m, were drilled to maintain the proper overlap with the data from the previous two holes. No cores were oriented. The nonmagnetic core barrel was deployed on even-numbered cores. No core barrels were drilled over. The cored interval was 101.0 m, with 103.1 m recovered. Coring at Site 1241 yielded 810.1 m, representing an average recovery of 101% (Table T1).
Taking advantage of morning light, a supply vessel from Panama (VIVEROS) that had arrived on site during the early dark hours of 25 May came alongside the vessel. This vessel was contracted to bring out 150 boxes of D-tubes to replenish the nearly depleted stock. In addition to the much-needed D-tubes, the vessel also delivered 336 kg of fresh fruit, fresh vegetables, and cheese. The VIVEROS was secured to the port side of the JOIDES Resolution at 0630 hr and drifted in the lee of the larger vessel during unloading. One hr was needed to unload the supplies.
After the supply boat was released, the vessel was secured for transit and departed for the transit to the last site of the leg at 0800 hr on 25 May.