Site summaries (continued)

Site UMK-3B (Umnak Plateau): Pliocene–Pleistocene

54°25.1′N 170°14.6′W (WGS 84)
Water depth (m)
Target drilling depth (mbsf):
Approved maximum penetration (mbsf):
Previous drilling in area:
DSDP Site 185
Relocated from Site UMK-3A to shot point 2617 on the Line 2 of Cruise L6-80 of USGS R/V Lee (EPSP December 2005)
Survey coverage (track map, seismic profile); sediment cores:
USGS R/V Lee Cruise L6-80 (1980):
• Single channel seismic: Line 2 and crossing Line 6, Shotpoint 721 (Figs. AF52, AF58, AF59)
• Seismic velocity: DSDP Site 185 measurement; ref. interval velocity by USGS R/V Lee Cruise L6-80, Line 6
R/V Hakuhou-maru Cruise KH99-3 Leg 3 (1999):
• Regional overview map with track line (Fig. AF55)
• 3.5 kHz
• Swath bathymetry (Fig. AF57)
• Piston core (9.6 m)
Objective (see text for complete details):
Monitor surface water exchange from the Pacific into the Bering Sea and surface conditions in the easternmost part of the Bering Sea.
Reconstruct Pliocene–Pleistocene high-resolution paleoceanography and investigate Bering/Arctic Gateway history and sea ice and water mass distribution, distal to Pacific water
Drilling/coring program:
Holes A, B, and D: APC with core orientation to 200 mbsf, Hole C to 25 mbsf
Temperature measurements: 3 APCT-3
Downhole logging program:
Wireline logging: triple combo, FMS-sonic
Anticipated lithology:
Hemipelagic silty clay with siliceous and calcareous microfossils. Estimated bottom age = Pliocene.

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