167 Preliminary Report

OPERATIONS REPORT

SITE 1016 (PROPOSED SITE CA-11E)

Hole 1016A
Site 1016 is located approximately 7 nmi outside of a former chemical munitions dumping area. A subsea camera survey of the seafloor was conducted for safety reasons within a 50-m perimeter of the positioning beacon. The results of the camera survey were negative and Hole 1016A was spudded at 1600 hr on 14 May. APC Cores 167-1016A-1H through 10H were taken from 0 to 93.1 mbsf with 104.3% recovery. Cores 1H and 2H were run through the MST and then split open to search for artifacts. The search results were negative, and APC coring proceeded. Adara temperature measurements were taken on Cores 4H, 6H, and 8H. XCB Cores 11X through 35X were taken down to 315.5 mbsf with 92.5% recovery. Drilling was slow in a massive chert and porcellanite layer starting at approximately 298 mbsf. One MDCB Core 167-1016A-36N was taken down to 316.5 mbsf with 1 m of advancement and 0.44 m of chert recovered. Because of the slow progress from 298 to 316 mbsf with only fragments of chert recovered, the decision was made to stop coring at 316 mbsf and log the hole before reaching the planned depth of 440 mbsf. Hole 1016A was logged with the Triple Combination, the FMS/Sonic/GR, and the GHMT tool strings from 313 to 60 mbsf with good results.

HOLE 1016B
The vessel was offset 10 m to the west and Hole 1016B was spudded at 0800 hr on 17 May. APC Cores 167-1016B-1H through 23H were taken from 0 to 210.8 mbsf with 103.5% recovery. Oriented cores were obtained starting with Core 3H.

HOLE 1016C
The vessel was offset 10 m to the west and Hole 1016C was spudded at 1140 hr on 18 May. APC Cores 167-1016C-1H and 2H were taken down to 18.7 mbsf with 100.3% recovery.

Hole 1016D
Hole 1016D was spudded at 1315 hr on 18 May. APC Cores 167-1016D-1H through 16H were taken down to 150.5 mbsf with 102.8% recovery. The drill string was tripped back to the surface and secured for the 5-hr transit to Site 1017 (proposed Site CA-9D) by 0815 hr on 19 May.

SITE 1017 (PROPOSED SITE CA-9D)

Hole 1017A
Hole 1017A was spudded at 1615 hr on 19 May. Core 167-1017A-1H was taken from 0 to 9.5 mbsf with 100% recovery. A full barrel prevented the establishment of an accurate mudline and the hole was abandoned.

Hole 1017B
The drill pipe was raised 5 m, and Hole 1017B was spudded at 1645 hr on 19 May. APC Cores 167-1017B-1H through 13H were taken from 0 to 119.1 mbsf with 96.7% recovery. Adara temperature measurements were taken on Cores 4H, 6H, and 8H. While extracting the core liner following Core 13H, the lower end of the liner fragmented. Safety procedures for handling overpressurized core liners were in place, and no injuries occurred. XCB Cores 167-1017B-14X through 23X were taken down to 204.2 mbsf with 92.4% recovery.

Hole 1017C
The vessel was offset 10 m to the west and Hole 1017C was spudded at 1045 hr on 20 May. APC Cores 167-1017C-1H through 8H were taken from 0 to 73.8 mbsf with 105.2% recovery. Oriented cores were obtained starting with Core 3H. XCB Cores 167-1017C-9X through 19X were taken down to 174.3 mbsf 97.2% recovery. While retrieving Core 14X, the sinker bars hit the crown sheave, parting the coring line. The sinker bars and the oil saver fell to the rig floor. No injuries occurred as a result of this incident, but additional safety equipment was installed on the coring winch unit. The winch unit now comes to a complete stop automatically at 10 mbrf and must be reset to continue advancing upward. Coring resumed with the forward coring line.

Hole 1017D
The vessel was offset 10 m to the west, and Hole 1017D was spudded at 0045 hr on 21 May. APC Cores 1017D-1H through 9H were taken down to 80.1 mbsf with 105.7% recovery. XCB Cores 167-1017D-10X through 12X were taken down to 107.9 mbsf with 78.8% recovery.

Hole 1017E
The vessel was offset 10 m to the west, and Hole 1017E was spudded at 0945 hr on 21 May. APC Cores 167-1017E-1H through 3H were taken down to 24.9 mbsf with 103.3% recovery. The drill string was tripped back to the surface and secured for the 18-hr transit to Site 1018 (proposed Site CA-8A) by 1330 hr on 21 May.

SITE 1018 (PROPOSED SITE CA-8A)

Hole 1018A
Site 1018 is located approximately 6 nmi outside an area marked "Explosive Dumping Area Disused". A subsea camera survey of the seafloor was conducted within a 50-m perimeter of the coordinates for Site 1018. One object with approximately the size and shape of a 55-gallon drum was found approximately 50 m south of Site 1018. The vessel was offset 100 m to the northeast of the Site 1018 coordinates, or 150 m from the object. The results of the camera survey at the new position were negative. Hole 1018A was spudded at 1830 hr 22 May. APC Cores 167-1018A-1H through 10H were taken down to 90.4 mbsf with 104.4% recovery. Cores 1H and 2H were run through the MST, and then split open to search for artifacts. The search results were negative. Adara temperature measurements were taken on Cores 4H, 6H, 8H, and 10H. XCB Cores 167-1018A-11X through 45X were taken down to 426.2 mbsf with 99.0% recovery. A 30-barrel sepiolite mud pill was circulated, and a wiper trip was performed in preparation for logging. Hole 1018A was logged with the Triple Combination. The logging tool string would not pass below 225 mbsf, and was run from 225 to 80 mbsf. The logging tools were rigged down and another wiper trip to bottom was made. The Triple Combination was run from 341 to 232 mbsf. The caliper log indicated a large hole diameter, and further logs were canceled.

Hole 1018B
Hole 1018B was spudded at 1530 hr on 23 May. APC Cores 167-1018B-1H through 2H were taken from 0 to 19.2 mbsf with 101.3% recovery.

Hole 1018C
Hole 1018C was spudded at 1645 hr on 23 May. APC Cores 167-1018C-1H through 10H were taken down to 88.5 mbsf with 104.3% recovery. Oriented cores were obtained starting with Core 3H. XCB Cores 167-1018C-11X through 28X were taken down to 262.2 mbsf with 97.6% recovery.

Hole 1018D
The vessel was offset 10 m to the west, and Hole 1018D was spudded at 1700 hr on 26 May. APC Cores 167-1018D-1H through 11H were taken from 0 to 104.3 mbsf with 101.5% recovery. XCB Cores 167-1018D-12X through 18X were taken down to 167.7 mbsf with 96.9% recovery. The drill string was tripped back to the surface and secured for the 48-hr transit to Site 1019 by 1130 hr on 27 May.

SITE 1019 (PROPOSED SITE CA-1D)

Hole 1019A
Hole 1019A was spudded at 1100 hr on 29 May. A full barrel prevented the establishment of an accurate mudline, and the hole was abandoned.

Hole 1019B
Hole 1019B was spudded at 1145 hr on 29 May. Again, a full barrel prevented the establishment of an accurate mudline, and the hole was abandoned.

Hole 1019C
Hole 1019C was spudded at 1230 hr on 29 May. APC Cores 167-1019C-1H through 8H were taken down to 74.8 mbsf with 107.1% recovery. Adara temperature measurements were taken on Cores 4H, 6H, and 8H. The temperature profile was linear, with a gradient of 0.057°C/m. XCB Cores 167-1019C-9X through 26X were taken down to 247.8 mbsf with 77.4% recovery. Gas expansion caused significant gaps in the core, resulting in less than 100% core recovery. The gas was biogenic in origin and consisted mainly of methane. A 20-barrel sepiolite mud pill was circulated and a wiper trip was performed in preparation for logging. Hole 1019C was logged with the Triple Combination, FMS/Sonic, and GHMT tool strings.

Hole 1019D
The vessel was offset 10 m south, and Hole 1019D was spudded at 0245 hr on 31 May. APC Cores 167-1019D-1H through 7H were taken down to 60.6 mbsf with 101.3% recovery. Oriented cores were obtained starting with Core 3H. XCB Cores 167-1019D-8X through 24X were taken down to 223.8 mbsf with 74.5% recovery. The reduced core recovery was caused by gas expansion similar to Hole 1019C.

Hole 1019E
The vessel was offset 10 m south, and Hole 1019E was spudded at 2145 hr 31 May. APC Cores 167-1019E-1H through 12H were taken down to 109.5 mbsf with 102.4% recovery. The drill string was tripped back to the surface and secured for the 8-hr transit to Site 1020 by 0730 hr on 1 June.

SITE 1020 (PROPOSED SITE CA-4A)

Hole 1020A
Hole 1020A was spudded at 2030 hr 1 June. A full barrel prevented the establishment of an accurate mudline, and the hole was abandoned.

Hole 1020B
The drill string was raised 5 m and Hole 1020B was spudded at 2115 hr on 1 June. APC Cores 167-1020B-1H through 18H were taken down to 169.3 mbsf with 105.1% recovery. Adara temperature measurements were taken on Cores 4H, 6H, and 8H. Oriented cores were obtained starting with Core 3H. XCB Cores 167-1020B-19X through 30X were taken down to 278.8 mbsf with 79.5% recovery. Hole 1020B was logged with the Triple Combination, FMS/Sonic, and GHMT strings with excellent results.

Hole 1020C
The vessel was offset 10 m to the south, and Hole 1020C was spudded at 0545 hr on 4 June. APC Cores 167-1020C-1H through 16H were taken down to 146.8 mbsf with 104.0% recovery. Oriented cores were obtained again starting with Core 3H. XCB Cores 167-1020C-17X through 25X were taken down to 233.2 mbsf with 100.5% recovery.

Hole 1020D
The vessel was offset 10 m to the south and Hole 1020D was spudded at 0715 hr on 5 June. APC Cores 167-1020D-1H through 17H were taken down to 156.2 mbsf with 104.8% recovery. The drill string was tripped back to the surface and secured for the 12-hr transit to Site 1021 by 0130 hr on 6 June.

SITE 1021 (PROPOSED SITE CA-5A)

Hole 1021A
Hole 1021A was spudded at 2000 hr on 6 June. A full barrel prevented the establishment of an accurate mudline, and the hole was abandoned.

Hole 1021B
Hole 1021B was spudded at 2100 hr on 6 June. APC Cores 167-1021B-1H through 18H were taken down to 169.5 mbsf with 104.6% recovery. Adara temperature measurements were taken on Cores 4H, 6H, and 8H. Oriented cores were obtained starting with Core 3H. XCB Cores 167-1021B-19X through 33X were taken down to 310.1 mbsf with 96.1% recovery.

Hole 1021C
The vessel was offset 10 m to the south, and Hole 1021C was spudded at 1545 hr on 8 June. APC Cores 167-1021C-1H through 18H were taken down to 164.1 mbsf with 103.8% recovery. Oriented cores were obtained again starting with Core 3H.

Hole 1021D
The vessel was offset 10 m south, and Hole 1021D was spudded at 1330 hr on 9 June. APC Cores 167-1021D-1H through 15H were taken down to 138.5 mbsf with 103.9% recovery. The drill string was tripped back to the surface and secured for the 12-hr transit to Site 1022 by 1530 hr on 10 June.

SITE 1022 (PROPOSED SITE CA-2B)

Hole 1022A
Hole 1022A was spudded at 1015 hr on 11 June. APC Cores 167-1022A-1H through 18H were taken down to 166.0 mbsf with 103.4% recovery. Adara temperature measurements were taken on Cores 4H, 6H, and 8H. Oriented cores were obtained starting with Core 3H.

Hole 1022B
The vessel was offset 10 m to the south, and Hole 1022B was spudded at 0215 hr on 12 June. APC Cores 167-1022B-1H through 11H were taken down to 101.2 mbsf with 105.7% recovery.

Hole 1022C
The vessel was offset 10 m to the south and Hole 1022C was spudded at 1115 hr on 12 June. APC Cores 167-1022C-1H through 17H were taken to 159.5 mbsf with 103.3% recovery. XCB Cores 167-1022C-18X through 42X were taken down to 387.7 mbsf with 93.9% recovery. Hole 1022C was logged with the Triple Combination, FMS/Sonic, and GHMT tool strings with excellent results. The drill string was tripped back to the surface and secured for the 18-hr transit to San Francisco by 1030 hr on 15 June.

Site 1010-1015 Operations

To 167 Operations Resume and 167 Site Summary

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