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doi:10.2204/iodp.proc.323.108.2011

Operations

Five holes were cored at Site U1344 (Table T1). Hole U1344A used the advanced piston corer (APC) and extended core barrel (XCB) systems to core to 745.0 m drilling depth below seafloor (DSF). Hole U1344A was then successfully logged with the triple combination (triple combo) and Formation MicroScanner (FMS)-sonic logging tool strings. The second hole, planned as a dedicated microbiology hole, was cut short because of contamination caused when the core liner split during mudline coring. Therefore, Hole U1344C was assigned to microbiology. Hole U1344D was cored with the APC system to 286.5 m DSF. The last hole, Hole U1344E, was cored with the APC system to 202.8 m DSF. A complete set of site-specific tide tables provided by the science party was used to make adjustments relative to the initial mudline core and for each successive core in each hole. Coring was generally routine except for encountering biogenic methane in the cores, which complicated the curation of all cores at this site. APC coring for Site U1344 totaled 87 cores, 781.8 m penetrated, and 791.1 m recovered, for 101.2% core recovery. XCB coring for Site U1344 totaled 52 cores, 489.9 m penetrated, and 384.1 m recovered, for 78.4% core recovery. The total cored interval for Site U1344 was 1271.7 m, with 1175.2 m of core recovered, for a 92.4% total core recovery. The time spent at Site U1344 was 8.5 days.

Hole U1344A

The first APC barrel recovered 9.1 m of core, and an official seafloor depth was established at 3183.4 m drilling depth below rig floor (DRF). Hole U1344A was spudded at 0932 h on 14 August 2009 (all times are ship local time, Universal Time Coordinated [UTC] – 11 h). APC coring using nonmagnetic coring assemblies continued through Core 323-U1344A-26H to 245.6 m DSF. At this point, the XCB system was deployed, and coring continued through Core 323-U1344A-79X to 745.0 m DSF. The coring tools were secured, and the hole was swept clean and displaced with 200 bbl of prepared high-viscosity logging mud. No fill was identified at total depth. The end of pipe (EOP) was placed at ~100.0 m DSF. Two logging strings were deployed. The triple combo tool string reached the total hole depth of 745 m wireline log depth below seafloor (WSF), and good-quality logs were obtained. The second logging string consisted of the FMS-sonic tool. This tool string also reached total depth on the first pass but reached only 725 m WSF on the second pass because hole conditions began to deteriorate. Good data were obtained on both passes. APC core recovery for Hole U1344A was 103.5%, with 264 m recovered. XCB core recovery for Hole U1344A was 78.4%, with 384.1 m recovered. Total core recovery for Hole U1344A was 87%, with 648.1 m recovered.

Hole U1344B

The vessel was offset 20 m north of Hole U1344A. Hole U1344B was spudded with the APC system at 1335 h on 19 August. One APC core was recovered. Unfortunately, Core 323-U1344B-1H came to the surface with a split/damaged core liner and was unfit for microbiological studies.

Hole U1344C

The first APC barrel recovered 7.12 m of core, and an official seafloor depth was established at 3184.4 m DRF. Hole U1344C was spudded at 1505 h on 19 August. Both perfluorocarbon (PFT) and microsphere contamination testing methods were deployed. Four APC cores were recovered for microbiological study to 35.6 m DSF. Average APC core recovery in Hole U1344C was 94.13%, with 33.5 m recovered.

Hole U1344D

The ship was offset 20 m north of Hole U1344C. The APC was deployed, and Hole U1344D was spudded at 1940 h on 19 August. The first mudline core recovered 2.73 m of sediment, and the calculated seafloor was 3185.8 m DRF. APC coring using nonmagnetic coring assemblies continued through Core 323-U1344C-25H to 224.5 m DSF. At this point, the nonmagnetic coring equipment was changed to the standard APC coring system and coring continued. Coring with the APC system was suspended after Core 323-U1344D-32H at 286.5 m DSF. Only two cores, 323-U1344D-30H and 32H, required drillover. Overall core recovery for Hole U1344D using the APC coring system was 99.9%, with 286.1 m recovered.

Hole U1344E

The ship was offset 20 m north of Hole U1344D. The first APC barrel recovered 5.3 m of core, and an official seafloor depth was established at 3185.7 m DRF. Hole U1344E was spudded at 0750 h on 21 August. APC coring using nonmagnetic coring assemblies continued through Core 323-U1344E-23H. Coring was uneventful and continuous except for a 3 m section at 3276.5 m DRF that was drilled at the request of the stratigraphic correlator. APC core recovery for Hole U1344E was 101.4%, with 202.7 m recovered.

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