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doi:10.2204/iodp.sp.309312.2005

Site Summaries (continued)

Site GUATB-03B
Priority:
 		2 (Alternate site)
Position:
 		6°43.64'N, 91°56.66'W
Water depth (m):
 		3650
Sediment thickness (m):
 		240
Target drilling depth (mbsf):
 		350–600
Approved maximum penetration (mbsf):
 		Approved for unlimited penetration according to ODP Leg 206 Scientific Prospectus; same approval requested for IODP Expeditions 309 and 312.
Survey coverage:
 		Acquired during Ewing cruise EW9903, March–April, 1999:
  • MCS with 480 channels, 10 air guns
  • Refraction shooting 20 air guns recorded on OBHs
  • 3.5 kHz reflection
  • Hydrosweep multibeam bathymetry
     Site GUATB-03B is on EW9903 Line 22 between Lines 26 and 27 (see Figure F8)
    • Objective:
  • Establish regional variation in upper crustal processes, lithologic structure, and seawater interactions
  • Determine the extent of the massive lava flow encountered in Holes 1256C and 1256D to constrain the size of off-axis eruptions and drilling further afield in the GUATB-03 survey region
    • Drilling and Logging program:
  • Single bit to destruction or free-fall funnel deployment for an additional bit trip if recovery warrants
  • Because the sediment cover in the area has been documented in multiple cores, we request the option to wash through the sediment column a begin coring at the sediment/basement interface
    • Logging program:
  • Triple combo
  • FMS-sonic
  • BGR borehole magnetometer: oriented magnetic field measurements
  • UBI: acoustic borehole images
    • Nature of rock anticipated:
         		Pelagic sediment overlying basalt

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