Site Summaries (continued) | Table of Contents


Site: 1039R-A

Priority: 1
Position: 9°38.8574'N; 86°11.4338'W
Water Depth: 4375 m
Sediment Thickness: 420 mbsf is the depth to top of sill; sill thickness is not reliably resolvable from seismic records but is estimated to be ~30 m thick; sediment thickness below sill and above basement is estimated to be ~70 m; top of basaltic basement is estimated at ~520 mbsf, depending on thickness of sills.
Target Drilling Depth: 620 mbsf
Approved Maximum Penetration: 900 mbsf; approved to drill without coring to 445 mbsf Seismic Coverage: Position of site at shotpoint 3210 on seismic line BGR-99-44 (C. Ranero, pers. comm., GEOMAR, Kiel, Germany and C. Reichert, pers. comm., BGR, Hannover, Germany, 2001).
See the track line, seismic BGR-99-44, and seismic CR-20.

Objectives: The objectives of Site 1039R-A are to:

1. Investigate the petrology and alteration state of upper oceanic basement.

2. Determine fluid flow pattern in upper oceanic basement.

3. Install a modified CORK to monitor pressure and to sample basement fluids.

Drilling Program: Core with the RCB from ~370 mbsf to total depth (TD); install modified CORK for monitoring fluid flow, pressure, and temperature in upper oceanic basement.

Logging and Downhole: Formation temperature measurements (~5 DVTP), downhole logging with triple combo and FMS/sonic tool strings.

Nature of Rock Anticipated: Hemipelagic and pelagic sediments, gabbro sill, and basalt

Site Summaries (continued) | Table of Contents