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Priority:
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Primary
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Position:
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27°55.0017′S, 123°9.6568′W (WGS 84)
(27.9167°S, 123.1609°W)
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Water depth (m)
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3738
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Target drilling depth (mbsf):
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115–123 (including 100 m into basement)
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Approved maximum penetration (mbsf):
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Up to 100 m basement penetration
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Previous drilling in area:
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Closest drilling:
• DSDP Leg 92 Site 598, 550 nmi away
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Comments:
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International waters; 210 nmi from Ducie Island, United Kingdom
Preferred weather window: November–December
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Survey coverage
(track map, seismic profile):
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High-resolution seismics:
• Primary line(s): MCS Line 2 - Shotpoint 10020 (Fig. AF16)
• Crossing line(s): MCS Line 4 - Shotpoint 10708 (Fig. AF17)
• Subbottom profile, 3.5 kHz: Line 2 - JDay 004 at 05:37 GMT
• Detailed bathymetry and site location (swath bathymetry: collected with SIMRAD EM120) (Fig. AF18)
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Sediment cores:
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Two piston cores, two trigger cores, one gravity core, and six cores of an eight-barrel multicore
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Objectives
(see text for complete details):
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• Document the habitats, metabolic activities, genetic composition, and biomass of microbial communities in subseafloor sediments with very low total activity.
• Test how oceanographic factors (such as surface ocean productivity) control variation in sedimentary habitats, activities, and communities from gyre center to gyre margin.
• Quantify the extent to which these sedimentary communities may be supplied with electron donors by water radiolysis, a process independent of the surface photosynthetic world.
• Determine how the basement habitats, potential activities, and communities vary with crust age and hydrologic regime (from ridge crest to abyssal plain).
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Drilling/Coring program:
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• Triple to quadruple APC to basement; RCB upper 100 m of basement
• Temperature measurements: APCT-3
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Downhole logging program:
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Wireline logging: triple combo, FMS-sonic
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Anticipated lithology:
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Stiff dark yellowish brown clay grading to yellowish brown foraminifer-bearing clayey nannofossil ooze
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