The 24-nmi transit to Site 1211 was completed without incident in 2.5 hr at an average speed of 9.6 kt. After arriving at the site coordinates, the thrusters and hydrophones were lowered and the ship was switched over to dynamic positioning (DP) mode at 0225 hr on 27 September 2001, initiating operations at Site 1211.
An APC/XCB bottom hole assembly (BHA) was assembled and run to near the seafloor. The bit was positioned at 2912.0 meters below rig floor (mbrf), and Hole 1211A was spudded with the APC at 0915 hr on 27 September. The mudline core contained 2.85 m of sediment, establishing a seafloor depth of 2918.7 mbrf, or 2907.5 meters below sea level (mbsl) (Table T1). APC coring continued through Core 11H to 97.8 mbsf. While deploying Core 12H, the barrel dropped off the overshot and fell to the bottom. Two unsuccessful retrieval attempts and wireline trips were made before the core barrel was returned during the third run. The cause of the problem was identified as the safety tube located in the overshot, which had dislodged and resulted in the core barrel becoming jammed in the pipe. We resumed APC coring through Core 18H, which did not achieve full stroke, impeded by a chert layer. Coring was terminated at 158.9 mbsf, with an average recovery of 102.4%. The drill string was tripped up, clearing the seafloor at 0610 hr on 28 September and ending drilling at Hole 1211A.
The ship was offset 15 m to the north and the bit was positioned 2 m higher than at Hole 1211A to achieve stratigraphic overlap and position critical intervals away from core breaks. Hole 1211B was spudded at 0700 hr on 28 September, recovering 6.15 m of sediment in Core 1H, indicating a seafloor depth of 2917.4 mbrf, or 2906.2 mbsl. Coring with the APC continued through Core 17H at 151.6 mbsf. An incomplete stroke on Core 17H resulted in deployment of the XCB center bit to drill 1.6 m through a chert layer. The APC was redeployed for Cores 18H and 19H. When Core 19H did not stroke completely, coring operations were suspended at 169.9 mbsf. The drill string was retrieved, with the bit clearing the seafloor at 0625 hr on 29 September, ending drilling at Hole 1211B.
After leaving Site 1211, it was found that one of the critical intervals, the PETM, was condensed in Hole 1211B (see "Biostratigraphy"), and the stratigraphic overlap between Holes 1211A and 1211B was poor (see "Composite Depths"). As a result, the drillship returned to Site 1211 later in the leg.
After departing Site 1213, we proceeded due south to distance ourselves from the forecast center of severe tropical depression Krosa. During the night, the storm accelerated to 40 kt and moved rapidly to the northeast, passing north of the operational location. After passage of the storm, we reversed course and proceeded back to Site 1211. A total of 116 nmi were covered during the 22.7-hr transit at an average speed of 5.1 kt. At 1742 hr on 10 October, the ship was switched over to DP mode, recommencing operations at Site 1211.
An APC/XCB BHA was assembled and run to 2916.0 mbrf, near the seafloor. Hole 1211C was spudded with the APC at 0545 hr on 11 October. The mudline recovered 7.30 m of sediment, indicating a seafloor depth of 2918.2 mbrf, or 2906.9 mbsl. APC coring continued to a depth of 138.3 mbsf, and coring was terminated when the objective was achieved. Cores 4H through 15H were oriented, and APC coring averaged 101.9% recovery. The drill string was retrieved, clearing the rig floor at 0125 hr on 12 October and concluding operations at Site 1121.