IODP-MSP drilling and logging contractor: ESO
Hole: M0031A
Expedition: 325
Location:
Latitude: 19° 40.737' S
Longitude: 150 14.377° ' W
Logging
date:
Sea floor depth (driller's): 92 m DSL
Sea
floor depth (logger's): 110.4 m WRF
Total
core recovered: 5.68
m (13.21 % of cored section)
Lithologies:
The logging data was
recorded by the
Tool string |
Pass |
Top depth (m WMSF)
|
Bottom depth (m WMSF)
|
Pipe depth (m WMSF)
|
Notes |
1. ASGR |
|
|
|
Recorded through pipe |
|
The depths in the table are for the processed logs (after applying a depth shift to the sea floor).
Depth shift: The original logs were corrected for tool zero (+0.07 m) and shifted to the sea floor (-110.4 m).
Environmental
corrections: None were applied.
The ASGR log was acquired through the API pipe. In carbonate lithologies, where counts are normally very low, data were further attenuated by the presence of the drill pipe. Ideally, following logging through pipe the ASGR probe would be run in open hole and the signals compared and depth-matched for quality assurance/quality control. However, because of poor hole stability, this was not possible at this site. Total natural gamma radiation (TGR) is very low (~12.2 cps) despite logging speeds of 1 m/min. Although there is no clear differentiation between contributions of the different elements, changes in the concentration of uranium appear to coincide with the majority of variations in TGR. In order to identify statistically accurate results, negative component values (i.e., negative concentrations of potassium, uranium, and thorium) were removed from the dataset. When interpolated (assuming a gap between data points no greater than 10 m), both the original and edited datasets exhibit similar trends.
A null
value of -999.25 may replace invalid log values.
Additional
information about the drilling and logging operations can be found in the
Operations section of the Site Chapter in IODP Proceedings of Expedition 325.
For further questions about the data, please contact:
Dr Louise Anderson
University of
Leicester
Phone:
011-44-116-252-3327
Fax:
011-44--116-252-3918
E-mail:
IODP-UK
For any
web site-related problem please contact:
E-mail: Database Manager