The 43-nmi transit to Site 1267 (proposed Site WALV-11B) was accomplished in 4.4 hr at an average speed of 9.8 kt. The vessel was positioned over the site by 0940 hr on 21 April 2003. The corrected precision depth recorder depth estimate was 4378.4 meters below rig floor (mbrf).
Coring intervals, times, nominal recovery rates, core barrels that required drillover to be released from the sediment, and the deployments of the Advanced Piston Corer Temperature (APCT) tool, Tensor core orientation tool, and nonmagnetic core barrel are listed in Table T1.
Hole 1267A was initiated with the bit at 4365.0 mbrf. The seafloor depth estimated by the recovery of the first core barrel was established at 4356.6 mbrf. Piston coring advanced to 236.1 mbsf, where the formation became too indurated to continue with the APC. The bit was advanced by recovery on the last two cores because of incomplete strokes (Cores 208-1267A-24H and 25H). The hole was deepened with the XCB system to the target depth of 312.1 mbsf, which included a sample of the critical P/E and K/P boundary intervals. Active heave compensation was not used because of the fast rate of penetration (average rate of penetration = ~24 m/hr).
The Interstitial Water Sampler (IWS) was deployed for a second time following the conclusion of coring in this hole. The tool was lowered on the coring line to 312.1 mbsf and met with partial success. The internal data logger recorded 2.5 hr of data. The temperature, pressure, and differential pressure data were good, but the system failed to obtain a water sample. An internal software problem was suspected.
The bit was pulled clear of the seafloor at 2135 hr on 23 April, and the vessel was offset 20 m south. After obtaining a bottom water temperature with the APCT at 4360 mbrf, Hole 1267B was initiated, with the bit positioned 5 m shallower than its position during the initial mudline attempt at Hole 1267A. The seafloor depth calculated from the 3.1 m of recovery was 4366.4 mbrf. Piston coring advanced to 231.1 mbsf, and the hole was deepened with the XCB to the total approved depth of 329.0 mbsf.
The IWS was lowered on the coring line to 2267 mbrf on two runs to test the water sampler. The first run, between cutting Cores 208-1267B-19H and 20H, was not successful. The pressure fitting in the transducer manifold leaked and caused the sensors to fail. The second deployment was between Cores 208-1267B-32X and 33X. This time, the IWS was successful in obtaining a full set of data on all channels and recovering a water sample. At the conclusion of coring, the IWS was deployed for the last time during the leg. This time, the tool was run on the coring line to the bottom of the hole (329.0 mbsf). The data logger recorded 2.5 hr of temperature and pressure data. A software update appeared to have fixed the sampling program, but no water sample was secured because of a broken soldered joint on the servo motor.
The total cored interval at Site 1267 was 641 m, and the recovered interval was 637 m (average nominal recovery = 99%).
Six downhole temperature measurements (Hole 1267A: 37–123 mbsf) and one bottom water temperature measurement (Hole 1267B) with the APCT yielded an initial temperature gradient estimate of 4.3°C/100 m.
The drill string was recovered, and the beacon was retrieved. The coring line was coated with preservative, and the bottom-hole assembly was deconstructed. After the hydrophones and thrusters were secured, the vessel departed on the long journey to Rio de Janeiro at 1648 hr on 26 April.