Wireline Standard Data Processing

ODP logging contractor: LDEO-BRG

Hole: 1072A

Leg: 174A

Location: New Jersey Rise (NW Atlantic)

Latitude: 39° 21.9370' N

Longitude: 72° 41.6675' W

Logging date: July, 1997

Bottom felt: 109.5 mbrf

Total penetration: 306.8 mbsf

Total core recovered: 151.9 m (49.5 %)

Logging Runs

Logging string 1: DIT/APS/HLDS/HNGS

The wireline heave compensator was not operational, due to electrical problems.

Bottom-hole Assembly

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 this discrepancy are ship heave and drill string and/or wireline stretch.

DIT/APS/HLDS/HNGS: Bottom-hole assembly at ~44.5 mbsf.

Processing

Depth shift: No depth match was necessary as only one logging run was recorded. The original logs have been depth shifted to the sea floor (- 110 m). The amount of depth shift corresponds to the water depth observed on the logs and differs 0.5 m from the "bottom felt" depth given by the drillers.

Gamma-ray processing: HNGS data have been processed to correct for borehole size and type of drilling fluid.

High-resolution data: Neutron porosity data were recorded at a sampling rate of 5.08 cm.

Quality Control

During the processing, quality control of the data is mainly performed by cross-correlation of all logging data. Large (>12") and/or irregular borehole affects most recordings, particularly those that require eccentralization (APS, HLDS) and a good contact with the borehole wall. The hole was very enlarged below as indicated by the caliper tool which was completely open at 19 inches. As no correction could compensate for such large hole, HLDS and APS measurements in the lower section should be used with caution.

Data recorded through bottom-hole assembly should be used qualitatively only because of the attenuation on the incoming signal.

Hole diameter was recorded by the hydraulic caliper on the HLDS tool (LCAL).

Additional information about the logs can be found in the "Explanatory Notes" and Site Chapter, ODP IR volume 174A. For further questions about the logs, please contact:

Cristina Broglia
Phone: 845-365-8343
Fax: 845-365-3182
E-mail: Cristina Broglia