Introduction 4 Lithostratigraphy and sedimentology 12 Biostratigraphy and micropaleontology 19 Geochemistry 21 Paleomagnetism 23 Physical properties 28 Downhole measurements 31 Stratigraphic correlation 34 References
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Site U1460 ended at 1945 h on 15 August. A total of 133 cores were recovered with the HLAPC system; of the 606.7 m cored, 592.2 m was recovered (recovery = 97%). Hole U1460A After arriving at Hole U1460A (27°22.4948′S, 112°55.4296′E), preparations for coring commenced. As a result of previous difficulty establishing the mudline core at Site U1459 (broken core barrel), the seafloor was tagged with the bit to determine its precise location and whether it was as hard as the previous site. A nonmagnetic HLAPC core barrel was dressed with a core liner, picked up, and run into the hole. Hole U1460A was started at 0115 h on 13 August. Based on the recovery of the mudline core, the seafloor depth was calculated to be 214.5 mbsl. Coring continued with the HLAPC system through Core 356-U1460A-64F to 298.2 m DSF. After the mudline core, each core was advanced 4.7 m despite partial strokes on Cores 2F, 9F, and 64F. Hole U1460A was cored to a final depth of 300.1 m DSF (Core 65F). During coring, a routine slip, cut, and retermination of the coring line was performed. At the conclusion of coring, the drill string was pulled back to 231.6 m DSF and the top drive was set back. The drill string was pulled back to just above the seafloor, clearing the seafloor at 0605 h on 14 August and ending Hole U1460A. Of 300.1 m cored, 291.39 m of material was recovered (recovery = 97.1%). The total time spent on Hole U1460A was 33.25 h. Hole U1460B After offsetting the vessel 20 m north of Hole U1460A, preparations were made to begin Hole U1460B (27°22.4867′S, 112°55.4265′E). A nonmagnetic HLAPC core barrel was dressed with a core liner, picked up, and run into the hole. Hole U1460B was started at 1920 h on 14 August. Based on the recovery of the mudline core, the seafloor depth was calculated to be 214.4 mbsl. Coring continued with the HLAPC system through Core 356-U1460B-68F to 306.6 m DSF. After the mudline core, each core was advanced by recovery in an attempt to cover any gaps from Hole U1460A. Of the 306.6 m cored, 800.81 m was recovered (recovery = 98%). Also in this hole, in situ temperature measurements were made with the APCT-3 before recovering Cores 12F, 20F, 28F, 33F, and 36F. During coring, a routine slip, cut, and retermination of the coring line was performed. At the conclusion of coring, the drill string was pulled back to 260.7 m DSF and the top drive was set back. The drill string was pulled from the hole and the advanced piston corer/extended core barrel bit cleared the rig floor at 1940 h. The thrusters and hydrophones were pulled and secured, and at 1945 h on 15 August, Site U1460 concluded. The total time spent on Hole U1460B was 37.75 h.
Background and objectives 1 Operations 9 Lithostratigraphy 22 Biostratigraphy and micropaleontology 33 Geochemistry 36 Paleomagnetism 40 Physical properties 46 Downhole measurements 50 Stratigraphic correlation 64 References
Background and objectives 1 Operations 6 Lithostratigraphy 13 Biostratigraphy and micropaleontology 23 Geochemistry 26 Paleomagnetism 30 Physical properties 35 Downhole measurements 39 Stratigraphic correlation 50 References IODP Proceedings 2 V o l u m e 3 5 6 recovered and the thrusters and hydrophones were pulled back into the ship's hull before beginning the transit to Site U1464. The total time spent on Site U1463 was 147.0 h (6.13 days). Overall, the APC system penetrated 840.3 m and recovered 835.29 m (99.4%) and 189.1 m was cored with the HLAPC system with 189.69 m of material recovered (100.3%). The XCB system cored 265.0 m and recovered 126.56 m (47.8%). The overall recovery for Site U1463 was 89.0%. Hole U1463A After offsetting the vessel from the beacon, preparations for coring in Hole U1463A (18°57.9181′S, 117°37.4217′E) commenced. The APC/XCB system was assembled. Given the previous difficulty with the mudline core at IODP Sites U1459 and U1462 (broken and bent core barrels, respectively), we decided to begin coring operations with the XCB coring system. An XCB core barrel was dressed with a core liner and dropped in preparation for beginning Hole U1463A. We tagged the seafloor and calculated the water depth to be 145.8 meters below sea level (mbsl). Hole U1463A was started at 1925 h on 12 September 2015. The first XCB core barrel returned empty (Core 356-U1463A-1X) and a second barrel was dropped. Core 2X recovered 8.59 m of soft mud. We decided to abandon Hole U1463A in order to begin a new hole (U1463B) with the APC system. Hole U1463A advanced 19.4 m and recovered 8.59 m of core (44.3% recovery). Hole U1463A ended at 2030 h. The total time spent on Hole U1463A was 9.75 h. Hole U1463B Hole U1463B (18°57.9190′S, 117°37.4340′E) began at 2100 h on 12 September 2015 with recovery of a mudline core (7.88 m). The water depth was calculated to be 145.4 mbsl. We recovered Cores 356-U1463B-1H through 30H to 271.2 m DSF. The HLAPC system was then deployed and we recovered Cores 31F through 33F to 284.4 m DSF, at which depth piston coring refusal was reached. The XCB coring system was deployed and coring continued from Core
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