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Priority:
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Primary
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Position:
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26°28.8932′S, 137°56.3625′W (WGS 84)
(26.4816°S, 137.9394°W)
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Water depth (m)
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4284
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Target drilling depth (mbsf):
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120 m, including 100 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 597, 640 nmi away
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Comments:
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International waters; 250 nmi from Gambier Island, French Polynesia
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 3 - Shotpoint 6896 (Fig. AF10)
• Crossing line(s): MCS Line 1 - Shotpoint 6125 (Fig. AF11)
• Subbottom profile, 3.5 kHz: Line 3 - JDay 364 at 04:29 GMT
• Detailed bathymetry and site location (swath bathymetry: collected with SIMRAD EM120) (Fig. AF12)
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Sediment cores:
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Two piston cores, two trigger cores, one gravity core, and one 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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• 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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Homogeneous very dark brown clay with some mottling to very dark gray clay
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