Table T1. Operations, Site M0061.
| Core |
Coring method |
Date (2013) |
Time (UTC) |
Depth (mbsf) |
Recovered (m) |
Recovery (%) |
Mud type | Comments | |
|---|---|---|---|---|---|---|---|---|---|
| Top | Bottom | ||||||||
| 347-M0061A- | |||||||||
| 4 Oct | 1230 | Seabed template not lowered, piston fired in water at 0.5 m above the estimated mudline to capture sediment/water interface; on recovery, water depth reassessed and string lowered to calculated mudline | |||||||
| 1H | PCS | 4 Oct | 1335 | 0.00 | 1.50 | 1.53 | 102 | Seawater | Drilled out 3.3 m from last sample, added pipe, and lowered seabed template to seabed |
| 2H | PCS | 4 Oct | 1355 | 1.50 | 4.80 | 3.44 | 104.24 | Seawater | 65 bar; good fire sequence, good recovery |
| 3H | PCS | 4 Oct | 1520 | 4.80 | 8.10 | 3.28 | 99.39 | Seawater | |
| 4H | PCS | 4 Oct | 1555 | 8.10 | 11.20 | 3.18 | 102.58 | Seawater | Barrel stuck; eventually freed after hammering with overshot and pumping water |
| 5H | PCS | 4 Oct | 1630 | 11.20 | 11.20 | 0.00 | 0 | Seawater | Stopped to fix deck lights, which failed to come back on following a ship power failure |
| 6H | PCS | 4 Oct | 1718 | 11.20 | 14.50 | 2.13 | 64.55 | Seawater | Piston fired at 60 bar |
| 7H | PCS | 4 Oct | 1834 | 14.50 | 17.60 | 3.18 | 102.58 | Seawater | Pressurized up to 220 bar without any apparent firing point; on release of pressure and recovery of the corer, we had collected 3.3 m of very fine to fine sand |
| 8H | PCS | 4 Oct | 1935 | 17.60 | 20.80 | 3.17 | 99.06 | Seawater | Prepared drill floor to lift template; lifted template and positioned large transponder; returned template to seabed and replaced mouseholes |
| 9H | PCS | 4 Oct | 2030 | 20.80 | 24.10 | 3.30 | 100 | Guar | Washed down to 24.1 mbsf and ran PCS |
| 10H | PCS | 4 Oct | 2054 | 24.10 | 25.10 | 3.15 | 315 | Guar | Pressure reached 135 bar; sample probably sucked in |
| 11S | HS | 4 Oct | 2220 | 25.10 | 25.20 | 0.10 | 100 | Guar | Hammer sample when no progress made while washing down from 24.1 mbsf; recovered rock—looks like bedrock rather than clast or pebble |
| 4 Oct | 2300 | Pulled string | |||||||
| 347-M0061B- | |||||||||
| 4 Oct | 2340 | Started lowering drill string | |||||||
| 1H | PCS | 5 Oct | 0000 | 0.00 | 2.80 | 2.83 | 101.07 | Seawater | Fired piston from ~0.5 m above seabed |
| 2H | PCS | 5 Oct | 0025 | 2.80 | 6.10 | 3.43 | 103.94 | Seawater | |
| 3H | PCS | 5 Oct | 0113 | 6.10 | 9.40 | 3.44 | 104.24 | Seawater | 10 bar then zero |
| 4H | PCS | 5 Oct | 0143 | 9.40 | 12.70 | 3.15 | 95.45 | Seawater | Not a clean fire; 50 bar, dropped then went up to 125 bar before dropping away quickly; bottom of core run was more silty if not sandy; changed to Guar mud while drilling down |
| 5H | PCS | 5 Oct | 0211 | 12.70 | 16.00 | 3.17 | 96.06 | Guar | 50 bar, then up to 80 bar, then rising to 100 bar before dropping and then rising to 125 bar and dropping all the way; possible sand/silt layers; still very soft at the bottom |
| 6H | PCS | 5 Oct | 0245 | 16.00 | 19.30 | 3.30 | 100 | Guar | Same firing pattern as before but less pressure after firing |
| 7H | PCS | 5 Oct | 0320 | 19.30 | 22.60 | 3.21 | 97.27 | Guar | 50 bar, then up to 80 then 100 then 130 bar before dropping to zero; still sand indications |
| 8H | PCS | 5 Oct | 0450 | 22.60 | 25.90 | 3.09 | 93.64 | Guar | Fired as normal but pressure did not drop fully and then went up over 125 bar until the pipe was lifted |
| 5 Oct | 0506 | Tool stuck in the hole, hammer overshot but no release; ran overshot release and tried to free by pumping; recovered on the second attempt | |||||||
| 9H | PCS | 5 Oct | 0545 | 25.90 | 28.70 | 2.83 | 101.07 | Guar | Fired: other than slight pressure flicker, firing point was not discernible and continued upward, stopped by the driller at 125 bar; did not release pressure until rooster box was lifted; pumped before attempting recovery |
| 5 Oct | 0604 | Unable to release corer despite hammering; released overshot to allow more pumping; eventually successful in recovering corer after pumping and hammering with the overshot | |||||||
| 5 Oct | 0645 | Tripped pipe to allow bump over for Hole M0061B | |||||||
| 347-M0061C- | |||||||||
| 5 Oct | 0700 | ||||||||
| 1H | PCS | 5 Oct | 0725 | 0.00 | 3.30 | 3.41 | 103.33 | Seawater | 50 bar, right down to zero |
| 2H | PCS | 5 Oct | 0805 | 3.30 | 6.60 | 3.42 | 103.64 | Seawater | Fired normally |
| 3H | PCS | 5 Oct | 0850 | 6.60 | 9.90 | 3.44 | 104.24 | Seawater | Fired normally |
| 4H | PCS | 5 Oct | 0915 | 9.90 | 13.20 | 3.14 | 95.15 | Seawater | Fired, pressure up then down to zero |
| 5H | PCS | 5 Oct | 1035 | 13.20 | 16.50 | 3.37 | 102.12 | Seawater | 50 bar, down to zero |
| 6H | PCS | 5 Oct | 1110 | 16.50 | 19.80 | 3.22 | 97.58 | Seawater | 60 bar, down to zero |
| 7H | PCS | 5 Oct | 1145 | 19.80 | 23.10 | 3.17 | 96.06 | Seawater | 110 bar, had to release pressure at pump |
| 5 Oct | 1220 | Tripped pipe | |||||||
| Completed and awaiting pilot for transit to Site M0062 | |||||||||
HS = hammer sampler, PCS = piston coring system.
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