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Priority:
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Alternate
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Position:
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28°26.7840′S, 131°23.4215′W (WGS 84)
(28.4464°S, 131.3904°W)
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Water depth (m)
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4221
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Target drilling depth (mbsf):
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22
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Approved maximum penetration (mbsf):
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Until basement is encountered
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Previous drilling in area:
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Closest drilling:
• DSDP Leg 92 Site 597, 600 nmi away
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Comments:
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International waters; 240 nmi from Pitcairn 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 3 - Shotpoint 8705 (Fig. AF13)
• Crossing line(s): MCS Line 1 - Shotpoint 7871 (Fig. AF14)
• Subbottom profile, 3.5 kHz: Line 3 - JDay 001 at 14:12 GMT
• Detailed bathymetry and site location (swath bathymetry: collected with SIMRAD EM120) (Fig. AF15)
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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
• Temperature measurements: APCT-3
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Downhole logging program:
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None specified
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Anticipated lithology:
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Very dark brown pelagic clay with mottles appearing in top meter, increasing downcore; changes to dark yellowish brown with depth and composition changes to nannofossil-bearing clay
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