The 29-nmi transit to Site 1210 required just 3.25 hr, at an average speed of 8.9 kt. At 0750 hr on 23 September, the ship was switched over to dynamic positioning mode, initiating operations at Site 1210.
An APC/XCB bottom-hole assembly was assembled and run to near the seafloor. At 1358 hr on 23 September, the bit was positioned at 2581.0 meters below rig floor (mbrf), and a mudline core recovered 5.90 m of sediment, indicating a seafloor depth of 2584.6 mbrf, or 2573.5 meters below sea level (mbsl) (Table T1). APC coring continued to a depth of 233.9 mbsf without incident. Cores 4H through 26H were oriented. An incomplete stroke on Core 26H required deploying a center bit to drill through a ~1-m chert layer. APC Core 27H was deployed, but was also an incomplete stroke, resulting in a decision to terminate the hole at a depth of 242.4 mbsf. Recovery for APC coring in Hole 1210A averaged 103.3%. The drill string was tripped up to the seafloor with the bit clearing the seafloor at 1415 hr on 24 September, ending drilling at Hole 1210A.
The ship was offset 15 m to the north, and the bit was positioned 3 m deeper to provide stratigraphic overlap with Hole 1210A. Hole 1210B was spudded at 1645 hr on 24 September, recovering a 9.2-m APC core, which indicated a seafloor depth of 2584.3 mbrf, or 2573.2 mbsl. APC coring advanced the hole to 267.9 mbsf. Cores 4H through 27H were oriented. An incomplete stroke on Core 29H resulted in deployment of the XCB center bit to drill through a chert layer, followed by recovery of another piston core. This technique of drilling through chert layers when encountered (a total of 11.5 m was drilled) and then redeploying the APC to core between layers continued for 13 cores to a depth of 377.0 mbsf. Because of the diminishing core quality of a few of the last cores and the time being expended to drill through the chert layers, we terminated coring after Core 42H. APC coring recovery averaged 103.0% in Hole 1210B. The drill string was retrieved and the ship secured for transit to Site 1211 by 0000 hr on 27 September.