Transit from Site 1007 to 1008
The 55 nmi sea voyage to Site 1008 was made in 4.75 hr. A stand of drill collars was inspected during the transit, and an APC BHA was assembled. A Datasonics 354M beacon was dropped at 0105 hr on 4 April.
Hole 1008A
Hole 1008A was spudded at 0339 hr on 4 April. The water depth was 437.1 mbsl based on recovery of the mudline core. APC Cores 1008A-1H to 10H were taken from 0 to 78.7 mbsf with 100.7% recovery. Adara temperature tool heat-flow measurements were taken during coring of Cores 3H through 8H. The same cores were also oriented. A very hard layer was drilled from 34.1 to 35.1 mbsf. Core 9H required 80,000 lb overpull after washing for three minutes. Core 10H was rejected in a carbonate gravel; therefore, XCB coring was initiated. XCB Cores 11X-16X were cut from 78.7 to 134.5 mbsf with 12.3% recovery. The WSTP was deployed after Core 14X. XCB recovery was very poor in soft sediments with sporadic hard layers. Coring was terminated when the available operating time for this site was depleted. The bit cleared the seafloor at 1520 hr on 4 April.
Transit for Site 1008 to Site 1009
The 1.8-nmi transit to Site 1009 was made in dynamic positioning mode with the BHA suspended at 250 mbrf. A Datasonics 354M beacon was dropped at 1658 hr on 4 April. The drill site was moved about 73 m east of the original GPS site coordinates to obtain a thicker Holocene section.
Hole 1009A
Hole 1009A was initiated at 1825 hr on 4 April. The water depth was 307.9 mbsl based on recovery of the mudline core. APC Cores 1009A-1H to 16H were taken from 0 to 113.8 mbsf with 99.3% recovery. Adara temperature tool heat-flow measurements were taken during Cores 3H through 7H. The same cores were also oriented. A very hard layer was drilled from 22.0 to 23.5 mbsf. Core 7H was a full stroke that would not pull free with 50,000 lb overpull and was drilled over 6 m. The APC was advanced as far as possible; however, 6 cores had imploded tops or shattered liners and 7 of 16 cores were partial strokes because of the occurrence of sporadic hard layers. Consequently, we switched to the XCB coring system after Core 16H. XCB Cores 1008A-17X to 28X were cut from 113.8 to 226.1 mbsf with 69.6% recovery. Four of 12 XCB cores were jammed in the liner or core catcher. The WSTP was deployed after Cores 11X, 14X, 18X, 21X, and 24X. Coring was terminated when the available time ran out. The BHA was secured for sea voyage at 1600 hr on 5 April.
Sea Voyage from Site 1009 to Panama
The sea voyage from Site 1009 to Panama covered 1100 nmi in about 95.6 hr. Leg 166 ended with the first line ashore in Panama at 1600 hr, 10 April.