IODP

doi:10.2204/iodp.pr.341.2014

Operations

During Expedition 341 we conducted operations in 20 holes at 5 sites. A total of 6223 m was drilled, 5474 m was cored, and 3240 m of core was recovered (Table T2). Downhole logging was conducted in four holes. Here we describe the coring and logging operations at each site. The overall time distribution included 2.2 days in port, 5.9 days in transit, and 53.2 days on site.

Victoria port call

Expedition 341 began with the first line ashore at Victoria, British Columbia (BC; Canada), at Berth A South, Ogden Point, at 0745 h on 29 May 2013. The science party and technical staff boarded on the day of arrival. The majority of incoming cargo was loaded and off-going cargo was unloaded on 29 May as well. The following day, the Siem Offshore crew change was completed. All main port call activities, including preparation of the passage plan, were completed. The vessel was secured for sea with final maintenance checks performed prior to departure. Prior to departure, a new long-range identification and tracking system was delivered, installed, and commissioned. On the morning of 31 May, two tugs and the harbor pilot arrived at our location. The last line was released from shore at 1209 h, beginning the voyage to Site U1417. The pilot departed the vessel at 1237 h, and the vessel began the transit to the first site.

Transit to Site U1417

After a 1038 nmi transit from Victoria, BC, averaging 10.8 kt, the vessel arrived at Site U1417. The vessel stabilized over Site U1417 at 1101 h (UTC – 8 h) on 4 June 2013. The positioning beacon was deployed at 1121 h on 4 June and remained on the seafloor for the duration of the week. The position reference was a combination of GPS signals and a single acoustic beacon.

Site U1417

Site U1417 consisted of five holes, ranging in depth from 168.0 to 709.5 m DSF. A total of 198 cores were recovered at the site. A total of 811.18 m of core over an 836.5 m interval was recovered using the APC system (97% recovery). The cored interval with the XCB system was 381.8 m with recovery of 140.77 m of core (36.9%). The cored interval with the RCB system was 348.7 m with recovery of 146.92 m of core (42.1%). The overall recovery for Site U1417 was 70.1%. The total time spent on Site U1417 was 18.6 days. Downhole logging was run in Hole U1471E.

Hole U1417A

Hole U1417A was spudded at 0315 h on 5 June 2013. The seafloor was calculated to be 4187.7 meters below sea level (mbsl). Nonmagnetic core barrels and the APC were used for Cores 341-U1417A-1H through 20H. Temperature measurements were taken with the advanced piston corer temperature tool (APCT-3) shoe on Cores 4H, 10H, and 13H with good results. APC coring with wireline continued through Core 22H with the new half-length APC coring system using steel core barrels. At the conclusion of coring, the top drive was set back and the drill string was pulled from the hole. The seafloor was cleared at 0935 h on 6 June, ending Hole U1417A. A total of 22 piston cores were taken over a 168.0 m interval with a total recovery of 167.74 m of core (99.8%).

Hole U1417B

After clearing the seafloor, the vessel was offset 20 m east of Hole U1417A. Hole U1417B was spudded at 1225 h on 6 June 2013. Initially, orientation was planned and the FlexIT tool was deployed. High heave conditions and mechanical shearing forced abandonment of core orientation measurements in Hole U1417B. Nonmagnetic core barrels and the APC were used for Cores 341-U1417B-1H through 20H (0–176.3 m DSF). Cores 21H through 33H were cored using the half-length APC coring system. The XCB system was deployed for Cores 34X through 47X. Hole U1417B was terminated after Core 47X (358.8 m DSF). At the conclusion of coring, the top drive was set back and the drill string was pulled from the hole. The seafloor was cleared at 1645 h on 9 June, ending Hole U1417B. A total of 33 piston cores were taken over a 223.4 m interval at Hole U1417B with a total recovery of 211.97 m (94.9%). Fourteen XCB cores were cut over a 135.4 m interval with a recovery of 50.99 m (37.7%). The total core recovery for Hole U1417B was 262.96 m for the 358.8 m cored interval (73.3%).

Hole U1417C

After clearing the seafloor, the vessel was offset 20 m south of Hole U1417B. Hole U1417C was spudded at 1950 h on 9 June 2013. Orientation with the FlexIT tool was performed for Cores 341-U1417C-3H through 20H. Nonmagnetic core barrels and the APC were used for Cores 2H to 25H. Cores 26H to 29H were cored using the half-length APC coring system. At the conclusion of coring, the top drive was set back and the drill string was pulled from the hole. The seafloor was cleared at 0725 h on 11 June, ending Hole U1417C. A total of 28 piston cores were taken over a 225.0 m interval at Hole U1417C with a total recovery of 216.83 m of core (96.4%).

Hole U1417D

After clearing the seafloor, the vessel was offset 20 m west of Hole U1417C. Hole U1417D was spudded at 1155 h on 11 June 2013. Nonmagnetic core barrels and the APC were used for Cores 341-U1417D-1H through 18H. After Core 18H, the half-length APC coring system was deployed and APC coring continued through Core 37H. The XCB system was deployed for Core 38X. Coring with the XCB system continued through Core 59X, when the XCB cutting shoe returned to the surface without the cutting structure. Another XCB core barrel was dropped and was also damaged on recovery. The cutting shoe was then changed to a “softer sediment” type shoe, and coring continued. There was continuing evidence of an obstruction remaining in the hole, and after two more cutting shoe failures, coring was terminated after Core 65X at a final depth of 470.3 m DSF. The drill string was then pulled from the hole, and the bit cleared the rotary table at 1430 h on 16 June, ending Hole U1417D. A total of 36 piston cores were taken over a 220.1 m interval with a total recovery of 214.64 m of core (97.5%). There was one drilled interval during the APC section of the hole that was 3.8 m long. A total of 28 XCB cores were cut over a 246.4 m interval with 89.78 m of core recovered (36.4%). The total core recovery for Hole U1417D was 304.42 m for the 466.5 m cored interval (65.3%).

Hole U1417E

After clearing the seafloor, the vessel was offset 20 m to the west of Hole U1417D. Hole U1417E was spudded at 0230 h on 17 June 2013, and the hole was drilled without coring to 264 mbsf. The wash barrel was then pulled, and Cores 341-U1417E-2R through 5R were cut to 302.2 m DSF using the RCB system. The wash barrel was again deployed, and the hole was advanced with a drilled interval to 399.0 m DSF. Coring resumed from Core 7R and continued through Core 39R to 709.5 m DSF. In total, 37 cores were taken over a 348.7 m interval with a total recovery of 146.92 m of core (42.1%). There were two drilled intervals at Hole U1417E that added up to 360.8 m of advance without recovery.

In preparation for downhole logging, the hole was conditioned and the drill bit released before tripping the drill string and setting the end of the pipe at 81.4 m DSF. The triple combo logging string was rigged up and run into the hole, reaching a total depth of 624.0 m WSF at 0245 h on 21 June. Following the triple combo run, the VSI tool string was rigged up. During the rig up time, the Protective Species Observation watches began, and it became immediately apparent that a small group of northern fur seals was surrounding the vessel. The decision was made to terminate the VSI run for the day, pull back the VSI tool string, rig down and prepare the FMS-sonic tool string for deployment. The FMS-sonic tool string was then rigged up and deployed to a depth of 571.5 m WSF. The MSS was then rigged up and run; this run was the first deployment of the full MSS tool during IODP. The maximum depth the MSS reached was 204.0 m WSF because of a constriction in the hole. Protective Species Observation watches began at first light. No protected species were observed during this period within the 940 m diameter exclusion zone, so the GI gun source was ramped up starting 1 h after the watches commenced. After attempting to position the tool to the greatest possible depth, only one station was completed at ~211 m WSF, which consisted of two good shots. All logging equipment was rigged down by 1605 h on 22 June 2013, and the knobbies were removed from the drill string. The drill string was then pulled from the hole.

Transit to Site U1418

After a 137 nmi transit from Site U1417 averaging 10.3 kt, the vessel arrived at the second site. The vessel stabilized over Site U1418 at 1455 h on 23 June 2013, and the positioning beacon was deployed at 1515 h.

Site U1418

Site U1418 consists of six holes ranging in depth from 17.0 to 948.7 m DSF. A total of 185 cores were recorded for the site. The cored interval with the APC system was 810.0 m with a recovery of 819.08 m of core (101%). The cored interval with the XCB system was 48.5 m with a recovery of 22.80 m of core (47%). The cored interval with the RCB system was 688.7 m with a recovery of 495.20 m of core (72%). The overall recovery for Site U1418 was 86%. The total time spent on Site U1418 was 16.1 days.

Hole U1418A

Hole U1418A was spudded at 0015 h on 24 June 2013. The mudline core recovered 4.87 m of sediment, and the seafloor was calculated to be 3668.2 m drilling depth below sea level (DSL). All piston cores were tide-corrected at the drill down before each core was shot. Nonmagnetic core barrels and the APC were used for Cores 341-U1418A-1H through 13H. Temperature measurements were taken with the APCT-3 on Cores 4H, 7H, 10H, and 13H. APC coring continued through Core 33H with the half-length APC coring system using steel core barrels. The drill string cleared the seafloor at 1155 h on 25 June, ending Hole U1418A. A total of 33 piston cores were taken over a 209.9 m interval with a total recovery of 216.85 m of core (103%).

Hole U1418B

After clearing the seafloor, the vessel was offset 20 m east of Hole U1418A. Hole U1418B was spudded at 1355 h on 25 June. The mudline core recovered 7.57 m of sediment, and seafloor was calculated to be 3667.5 m DSL. Nonmagnetic core barrels and the APC were used for Cores 341-U1418B-1H and 2H. At the conclusion of coring, the bit was pulled clear of the seafloor, ending Hole U1418B at 1525 h on 25 June. Two piston cores were taken over a 17.0 m interval with a total recovery of 17.08 m of core (101%).

Hole U1418C

After clearing the seafloor, the vessel was offset 20 m south of Hole U1418B. Hole U1418C was spudded at 2030 h on 25 June 2013. The mudline core recovered 8.67 m of sediment, and seafloor was calculated to be 3666.0 m DSL. Nonmagnetic core barrels were used, and FlexIT orientation was performed for Cores 341-U1418C-1H through 7H. The hole was advanced from Core 9H through Core 19H to 118.2 m DSF using the half-length APC system. The core barrels were then switched back to the full-stroke nonmagnetic core barrels, and the hole was further advanced through Core 33H to 230.7 m DSF. The seafloor was cleared at 0710 h on 27 June, ending Hole U1418C. A total of 32 piston cores were taken over a 228.2 m interval with a total recovery of 229.48 m (100.6%).

Hole U1418D

After clearing the seafloor, the vessel was offset 20 m west of Hole U1418C. Hole U1418D was spudded at 0855 h on 27 June 2013. An offset water depth of 3666.5 m DSL was used after averaging the tide-corrected water depths from the first three holes. After spudding Hole U1418D, the hole was washed down to 3 m DSF and coring began with Core 341-U1418D-2H and continued with nonmagnetic core barrels through Core 26H to 230.0 m DSF. After Core 26H, the half-length APC coring system was deployed, and coring continued through Core 32H (257.3 m DSF). The XCB coring system was deployed for Cores 33X through 37X to 305.8 m DSF. The drill string was then pulled from the hole, and the seafloor was cleared at 0900 h, ending Hole U1418D. A total of 31 piston cores were taken over a 254.3 m interval with a total recovery of 256.97 m of core (101%). There was a single 3 m interval that was drilled without coring. A total of 5 XCB cores were cut over a 48.5 m interval with a recovery of 22.8 m (47%). Overall core recovery for Hole U1418D was 279.77 m for the 302.8 m cored interval (92%).

Hole U1418E

After clearing the seafloor, the vessel was offset 20 m south of Hole U1418D. While servicing the rig, a broken strand of wire was detected on the drilling line. Rather than risk a more severe problem, the decision was taken to slip and cut the drilling line to remove the damaged section of line. Hole U1418D was spudded at 1755 h on 29 June 2013. A tide-corrected offset depth of 3667.7 m DSL was established for seafloor depth. The hole was advanced to 78.0 m DSF without coring. Cores 341-U1418E-2H through 13H were cored with the APC to 181.6 m DSF. Total depth was reached at 1000 h on 30 June. The bit cleared the rotary table at 1900 h, ending Hole U1418E. A total of 11 APC cores were taken over a 100.6 m interval and recovered 98.7 m (98%). Two intervals were drilled without coring. The first was a 78.0 m interval and the second was a 3 m interval.

Hole U1418F

After clearing the seafloor, the vessel was offset 20 m west of Hole U1418E. Hole U1418F was spudded at 0445 h on 1 July 2013. Water depth was estimated from using an offset depth, which was calculated from using tide-adjusted depths for the first three holes of the site. After spudding Hole U1418F, the hole was drilled without coring to 260.0 m DSF. The wash barrel was then pulled, and Cores 341-U1418F-2R and 3R were cut to 279.4 m DSF but were empty when recovered on the rig floor. The core barrel, which had been dropped to cut Core 4R, was retrieved, and a core barrel with a bit deplugger was deployed. RCB coring with nonmagnetic core barrels resumed, and Cores 341-U1418F-4R through 72R were cut to 948.7 m DSF. A total of 71 RCB cores were cut over a 688.7 m interval and 495.20 m of core was recovered (72%).

After coring, the hole was conditioned for downhole logging. The bit was released in the hole, and the end of the drill pipe was set at 98.6 m DSF. The triple combo logging string was then rigged up and run into the hole, reaching a total depth of 599 m WSF at 2333 h on 7 July. The Schlumberger wireline winch experienced a transmission problem during the logging run and had to be repaired. The hole was then logged up, and the tools were pulled to surface and rigged down. After rigging down the triple combo tool string, the VSI tool was then rigged up and run into the hole. Protective Species Observation watches began at 0900 h 8 July. No protected species were observed within the 940 m diameter exclusion zone for 1 h, so the GI gun source was ramped up. Several attempts were made to collect data, but the tool had problems clamping into the borehole wall. The tool was pulled out of the hole and back to the surface and rigged down. The FMS-sonic tool string was then rigged up and deployed to a depth of 581 m WSF. Only a single pass was made with the tool string before it became stuck in the bottom-hole assembly (BHA). After trying unsuccessfully to free the tool string, the Kinley crimper was rigged up and deployed to crimp the logging cable inside the BHA before severing the cable. The pressure spike experienced with the line under tension was enough to free up the logging tools, and they were then pulled to the surface and rigged down. The drill string was pulled from the hole, and the BHA set back and secured for transit at 1630 h on 9 July, ending Site U1418. Total time spent on Hole U1418F was 213.5 h.

Transit to Site U1419

After a 47 nmi transit from Site U1418 averaging 9.9 kt, the vessel arrived at the third site. The vessel stabilized over Site U1419 at 2118 h on 9 July 2013, and the positioning beacon was deployed at 2135 h.

Site U1419

Site U1419 consists of five holes ranging in depth from 98.7 to 193.0 m DSF. A total of 101 cores were recovered for the site. The cored interval with the APC system was 517.9 m with a recovery of 473.0 m of core (91%). The cored interval with the XCB system was 74.4 m with a recovery of 14.86 m of core (20%). The overall recovery for Site U1419 was 82%. The total time spent on Site U1419 was 4.1 days.

Hole U1419A

Hole U1419A was spudded at 0200 h on 10 July 2013. A mudline core (341-U1419A-1H) recovered 7.43 m of sediment, and seafloor was calculated to be 687.4 m below sea level. All remaining piston cores were tide-corrected for differences relative to this first core at the drill down before each core was shot. Nonmagnetic core barrels and the APC were used for Cores 1H through 12H. APC coring continued through Core 20H with the half-length APC coring system using steel core barrels. The XCB coring system was deployed with a soft-formation cutting shoe for Cores 21X through 29X to 193.0 m DSF. Hole U1419A was terminated after Core 29X at 0235 h on 11 July. At the conclusion of coring, the hole was plugged with 85 bbl of 10.5 ppg mud and then abandoned. The top drive was then set back, and the drill string was pulled from the hole. A total of 20 APC cores were taken over a 118.6 m interval with a total recovery of 96.38 m of core (81%). A total of 9 XCB cores were cut over a 74.4 m interval with a recovery of 14.86 m of core (20%). Overall core recovery for Hole U1419A was 111.24 m for the 193.0 m cored interval (58%).

Hole U1419B

After clearing the seafloor, the vessel was offset 20 m east of Hole U1419A. Hole U1419B was spudded at 0530 h on 11 July 2013. The mudline core recovered 8.53 m of sediment, and seafloor was calculated to be 687.1 mbsl. All piston cores were tide-corrected at the drill down before each core was shot. Nonmagnetic core barrels were used and FlexIT orientation was performed for Cores 341-U1419B-1H through 10H. After Core 10H, the half-length APC system was deployed. The hole was advanced from Core 11H through Core 19H to 114.0 m DSF. Coring in Hole U1419B was terminated at 114.0 m DSF at 1740 h on 11 July. The hole was displaced with 48 bbl of 10.5 ppg mud, and the drill string was tripped from the hole with the top drive installed. The seafloor was cleared at 1940 h on 11 July, ending Hole U1419B. A total of 18 APC cores were taken over a 113.0 m interval and recovered 99.05 m of core (88%).

Hole U1419C

After clearing the seafloor, the vessel was offset 20 m south of Hole U1419B. The bit was then spaced out and lowered to the first shot depth, and Hole U1419C was spudded at 2100 h on 11 July 2013. An offset water depth of 685.8 mbsl (tide-corrected) was used after averaging the tide-corrected water depths from the two holes. Hole U1419C was washed down to 2.0 m DSF, and Cores 341-U1419C-2H through 11H (2.0–78.7 m DSF) were cored with nonmagnetic core barrels. The Core Barrel–Drill String Acceleration Tool (CB-DSA) was run on Cores 2H through 10H as an extension on the APC/XCB core barrel in order to record drill bit acceleration and vibration signals during drilling. However, the tool malfunctioned downhole and only ~30 min of reasonable data were recorded. Cores 11H through 20H (78.7–109.1 m DSF) were taken using the half-length APC system. APC recovery was affected by frequent rock clasts. Coring in Hole U1419C was terminated at 1230 h on 12 July. The hole was displaced with 43 bbl of 10.5 ppg mud, and the drill string was tripped from the hole with the top drive installed. The seafloor was cleared at 1425 h on 12 July, ending Hole U1419C. A total of 19 APC cores were taken over a 107.1 m interval with a total recovery of 100.37 m of core (94%).

Hole U1419D

After clearing the seafloor, the vessel was offset 40 m west of Hole U1419C. The bit was then spaced out and lowered to the first shoot depth, and Hole U1419D was spudded at 1720 h on 12 July 2013. An offset water depth of 687.5 mbsl (tide-corrected) was used after averaging the tide-corrected water depths from the first two holes. After spudding Hole U1419D, the hole was washed down to 5.5 m DSF and Cores 341-U1419D-2H through 14H were recovered from 5.5 to 80.1 m DSF. After Core 14H, the half-length APC coring system was deployed, and coring continued through Core 24H to 114.2 m DSF. The hole was displaced with 40 bbl of 10.5 ppg mud, and the drill string was tripped from the hole with the top drive installed. The seafloor was cleared at 0810 h on 13 July, ending Hole U1419D. A total of 20 APC cores were taken over a 103.7 m interval and recovered 105.10 m of core (101%). There were three drill intervals without coring, which added up to 10.5 m.

Hole U1419E

After clearing the seafloor, the vessel was offset 20 m north of Hole U1419D. An offset water depth of 685.5 mbsl (tide-corrected) was used after averaging the tide-corrected water depths from the first two holes. Hole U1419E was spudded at 0900 h on 13 July 2013 and washed down to 9.0 m DSF. Cores 341-U1419E-2H through 12H were recovered from 9.0 to 69.0 m DSF. After Core 12H, the half-length APC coring system was deployed, and coring continued through Core 19H to 98.7 mbsf. Coring was terminated at 1900 h on 13 July. The hole was displaced with 38 bbl of 10.5 ppg mud, the drill string was tripped back to 46.4 m DSF, and the top drive was set back. The bit cleared the rotary table at 2315 h, the drill floor was secured, and the thrusters were secured for transit at 0030 h on 14 July, ending Hole U1419E and Site U1419. A total of 15 APC cores were taken over a 75.5 m interval and recovered 72.1 m (95.5%). There were four drilled intervals without coring with a combined length of 23.2 m.

Transit to Site U1420

The vessel arrived at the fourth site after a 30 nmi transit from Site U1419 averaging 9.2 kt. The vessel stabilized over Site U1420 at 0345 h (UTC – 8 h) on 14 July 2013, and the positioning beacon was deployed at 0400 h.

Site U1420

Hole U1420A

After lowering the thrusters and hydrophones, the vessel switched from cruise mode to dynamic positioning mode and drill floor activities began. The RCB components for the BHA were assembled and run to the seafloor. The top drive was then picked up. The camera system was deployed for a seafloor survey. Following the survey, at 0850 h the seafloor was tagged with the bit at 259.4 DRF and the camera system was pulled back to the surface. Hole U1420A was spudded at 1045 h on 14 July 2013. Coring continued with Cores 341-U1420A-1R through 78R (0–749.2 m DSF). Because of increasing torque on the drill string, a ~200 m wiper trip was completed, preceded by a 50 bbl mud. Coring continued with Core 79R through 106R (749.2–1020.8 m DSF). A total of 106 rotary cores were taken over a 1020.8 m interval with a total recovery of 139.91 m of core (14%).

The hole was conditioned for downhole logging, and the bit was released in the hole. The end of the pipe was set at 93.29 m DSF. The sonic-induction tool string, containing the gamma ray tool, the sonic tool, and the older model resistivity tool, was run to 548 m WSF. After repeated attempts to run the tool string deeper, the string was pulled back to the BHA and another pass to 548 m WSF was performed. After logging up with the final pass, the tool string entered and became stuck in the BHA. The Kinley cutter was then rigged up, the crimper deployed, and the logging cable crimped, securing the tools in the BHA. The Kinley cutter was then deployed, and the logging cable was cut and pulled back to surface. The drill string was then pulled back to surface, the logging tools were removed from the BHA, and the BHA was secured. The thrusters and hydrophones were pulled at 0100 h 22 July. Total time spent on Hole U1420A was 189.25 h.

Transit to Site U1421

After an 11.9 nmi transit from Site U1420 averaging 7.9 kt, the vessel arrived at the final site. The vessel stabilized over Site U1421 at 0235 h on 22 July 2013, and the positioning beacon was deployed at 0245 h.

Site U1421

Site U1421 (proposed site GOAL-17B) consists of three holes. A total of 92 cores were recorded for the site. Twenty-six APC cores were collected over 140.8 m with a recovery of 114.47 m of core (81%). Sixty-six XCB cores were drilled over 606.3 m with a recovery of 61.54 m (10%). The overall recovery for Site U1421 was 23.6%.

Hole U1421A

Hole U1421A was spudded at 0730 h on 22 July 2013. The mudline core recovered 6.82 m of sediment, and the seafloor was calculated to be at 718.5 mbsl. Nonmagnetic core barrels and the APC were used for Cores 341-U1421A-1H through 8H, and orientation with the FlexIT tool was performed on Cores 2H through 8H. Cores 9H through 19H were recovered using the half-length APC coring system with steel core barrels. The XCB coring system was deployed for Cores 21X through 85X (702.7 m DSF). The total depth was reached at 1825 h on 26 July. A total of 19 APC cores were taken over a 96.4 m interval with a total recovery of 79.18 m of core (82%). A total of 66 XCB cores were cut over a 606.3 m interval with a recovery of 61.54 m of core (10%). Overall core recovery for Hole U1421A was 140.72 m for the 702.7 m cored interval (20.0%). The total time spent on Hole U1421A was 134.75 h.

The hole was conditioned for downhole logging, and the end of the drill pipe was set at 96.6 m DSF. The sonic-induction tool string was run to 698.3 m DSF, and two passes were made. The logging string was then pulled back to surface and rigged down at 0845 h on 27 July. The VSI tool was rigged up and run in the hole, and Protective Species Observation watches began at 0700 h. Nine stations were attempted. The tool was then pulled out of the hole to the surface and rigged down at 1630 h on 27 July. The bit cleared the seafloor at 1715 h on 27 July, ending Hole U1421A.

Hole U1421B

Hole U1421B was spudded at 1925 h on 27 July 2013. Coring in Hole U1421B was terminated at a total depth of 6.2 mbsf at 1925 h on 27 July, after the stratigraphic correlators confirmed that piston core shoot depth was incorrect. One piston core was taken over a 6.2 m interval with a total recovery of 6.23 m (101%).

Hole U1421C

After clearing the seafloor, the vessel was offset 20 m west of Hole U1421B. Hole U1421C was spudded at 2005 h on 27 July 2013. Nonmagnetic core barrels and the APC were used for Cores 341-U1421C-1H through 4H. Cores 5H through 6H were recovered using the half-length APC coring system to 38.2 m DSF. Temperature measurements were taken with the APCT-3 tool on Cores 4H and 6H. Coring in Hole U1421C was terminated when the core barrel for Core 6H became stuck in the BHA. The rig floor was secured at 1230 h on 28 July. The thrusters were then raised, and the vessel began the transit to Valdez, Alaska (USA), at 1245 h, ending Site U1421. The total time spent on Hole U1421C was 17.25 h. Six APC cores were taken over a 38.2 m interval with a total recovery of 29.06 m (76%).