Standard Processing - ODP Leg 156, Hole 948D

ODP logging contractor: LDEO-BRG

Well name: 948D

Leg: 156

Location: N Barbados Ridge (tropical NW Atlantic)

Latitude: 15° 31.464' N

Longitude: 58° 43.907' W

Logging date: June, 1994

Bottom felt: 4949 mbrf (used for depth shift to sea floor)

Total penetration: 538 mbsf

Total core recovered: none.

Logging Runs

Logging string 1: CBL/NGT (2 passes)

Logging string 2: ASI (Array Seismic Imager)

Wireline heave compensator was used to counter ship heave.

Bottom-hole Assembly/Casing

The following bottom hole assembly depth is as it appears on the logs after depth shift to the sea floor. As such, there might be a discrepancy with the original depth given by the drillers onboard. Possible reasons for depth discrepancies are ship heave, use of wireline heave compensator, and drillstring and/or wireline stretch.

CBL/NGT: Bottom-hole assembly at ~4.5 mbsf.

The casing summary is the following:

16 in casing: 0-43.4 mbsf

13 3/8 in casing: 43.4-475.9 mbsf

10 3/4 in casing: 475.9-535.3 mbsf.

Processing

Depth shift: Original logs have been depth shifted to the sea floor (- 4949 m).

Gamma-ray processing: No processing has been performed because of the low quality of the logs recorded through casing. The data should be used qualitatively only because of the high attenuation on the incoming signal.

Additional information about the logs can be found in the 'Explanatory Notes' and Site Chapter, ODP IR volume 156.

For any question about the data or about the LogDB database, please contact LogDB support: logdb@ldeo.columbia.edu.