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doi:10.2204/iodp.proc.339.103.2013

Operations

Port call

Expedition 339 began with the first line ashore at 0830 h, 16 November 2011, to Berth 12 in Ponta Delgada harbor on the island of Saõ Miguel, Azores (Portugal). The IODP technical crew change occurred as scheduled on 17 November, although a group of IODP personnel arrived on 18 November because of weather-related travel problems. The scientific complement joined the vessel on 18 November. Education and public relation activities were carried out on Friday and Saturday, 18 and 19 November, and included tours of the JOIDES Resolution for 175 students and 15 teachers from 4 local high schools (Escola Secundária Antero de Quental-Ponta Delgada, Escola Secundária das Laranjeiras-Ponta Delgada, Escola Secundária de Lagoa-Lagoa, and Escola Secundária da Ribeira Grande-Ribeira Grande), 12 students and professors from the Universidade dos Açores, 25 students and researchers from the Centro de Vulcanologia e Avaliação de Riscos Geológicos, 20 local visitors, 9 local government representatives, the Portuguese European Consortium for Ocean Research Drilling delegate, and 6 local journalists (press).

In addition to routine resupply of consumables and offloading of returning freight, the ship was loaded with ~600 MT of marine gasoil, 60 ST of sepiolite, and 20 ST of barite drilling mud. Just prior to concluding the port call in Ponta Delgada, the home port of registry for the JOIDES Resolution was changed from Monrovia, Liberia, to Limassol, Cyprus. The port call concluded when the last line was released at 0800 h, 22 November.

Site U1385

We arrived at Site U1385 (proposed Site SHACK-04A) at 0400 h Universal Time Coordinated, 25 November 2011, after a 68 h, 741 nmi journey from Ponta Delgada. Five holes were cored at this site using the advanced piston corer (APC) and nonmagnetic core barrels (Table T1). Four holes were cored to ~150 meters below seafloor (mbsf) and one to just 9.5 mbsf (1 core). A total of 67 cores were required to obtain 621.8 m of sediment (103.2% recovery). The advanced piston corer temperature tool (APCT-3) was deployed 12 times.

Hole U1385A

The initial pipe trip included routine measuring and “rabbiting” that occurs on the first deployment of the drill string. Following a 3 h survey of the seabed using the underwater camera system, during which no obstructions were observed, Hole U1385A was spudded with the APC at 2300 h, 25 November. Recovery of the first core established the seafloor depth at 2598 meters below rig floor (mbrf) (2587 mbsl). Piston coring with nonmagnetic core barrels advanced to a total depth of 151.1 mbsf (17 cores), which was the depth objective of the site. Total recovery in Hole U1385A was 155.9 m (103%). Cores 339-U1385A-4H through 17H were oriented with the FlexIt tool. The APCT-3 was deployed to take temperature measurements at 30 (Core 4H), 58.5 (Core 7H), 87 (Core 10H), and 115.5 (Core 13H) mbsf. The APC experienced partial strokes on Cores 14H and 17H. The last core had advanced only 7.7 m when the formation became firm and abruptly stopped the APC. The drill crew experienced difficultly extracting the sinker bars from the drill string prior to pulling out of the hole, requiring 4.5 h of IODP rig time to remove a deformed section of coring line before operations could resume. This involved the removal of 100 m of coring line, reheading the line, and redressing the oil saver.

Hole U1385B

Following a vessel offset of 20 m east of Hole U1385A, operations in Hole U1385B began at 0030 h, 27 November. The water depth calculated from the recovery of the first core was 2598 mbrf (2587 mbsl). Piston coring using nonmagnetic core barrels continued to a total depth of 147.9 mbsf (16 cores). Total recovery in Hole U1385B was 150.7 m (103%). APCT-3 measurements were made at 34.6 (Core 4H), 63.1 (Core 7H), 91.6 (Core 10H), and 120.1 (Core 13H) mbsf.

Hole U1385C

After a vessel offset of 20 m south of Hole U1385B, Hole U1385C was spudded at 1830 h, 27 November. Because the core barrel was retrieved full of sediment (9.87 m), a mudline depth could not be determined, and another hole was required to obtain a good mudline core. Total recovery in Hole U1385C was 9.9 m (104%).

Hole U1385D

Following a vessel offset of 20 m south, Hole U1385D was spudded at 2045 h, 27 November. The first core established a seafloor depth at 2595 mbsf (2584 mbsl). Piston coring advanced without incident to a final depth of 146.4 mbsf (16 cores) with an average recovery of 105.2%. Cores were oriented starting with Core 4H. The APCT-3 was deployed at 35.4 (Core 4H), 60.9 (Core 7H), 89.4 (Core 10H), and 117.9 (Core 13H) mbsf. Cores 15H and 16H were partial strokes and advanced by recovery. All cores were obtained with nonmagnetic core barrels. The bit cleared the seafloor at 1255 h, 28 November.

Hole U1385E

After a vessel offset of 20 m west of Hole U1385D, piston coring in the last hole at Site U1385 began at 1520 h, 28 November, using nonmagnetic core barrels. Seventeen cores were taken to the total depth of 148.7 mbsf by 0730 h, 29 November. We recovered 151.3 m of sediment (102%). Cores were oriented starting with Core 5H. The last three cores (Cores 15H through 17H) were partial strokes and advanced by recovery. Two cores were intentionally repositioned (Core 8H and 10H) to maintain a stratigraphic depth offset relative to the previous holes on this site. All cores were obtained with nonmagnetic core barrels. This hole concluded coring operations at this site.

The drill string was recovered and the bit cleared the seafloor at 0850 h, 29 November. Once the drilling equipment was secured and the beacon recovered, the vessel departed for the next site at 1515 h. Total time on site was 4.5 days.

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