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Core Orientation and Susceptibility Logging |
1 Institute of Solid Earth Physics, Allégt. 41, 5007 Bergen, Norway
2 Norsk Hydro, Sandsliveien 90, N-5001 Bergen, Norway
The magnetic susceptibility of a 180 m long core from the North Sea, covering the Middle Brent Group to Lower Cretaceous, has been measured at 2 cm intervals with a whole core sensor loop (MS2C) and on standard paleomagnetic samples collected at approximately 1 m intervals. The stratigraphic variations between the data sets reveal comparable features, suggesting that the sampling interval used yields a reliable record along this core. A relationship is demonstrated between gamma activity and susceptibility, the latter exhibiting more pronounced variations than the gamma logs, suggesting that susceptibility may be a useful lithomagnetic parameter for quantitative lithostratigraphic correlation. Non-linearity between gamma activity and magnetic susceptibility suggest that the latter may be treated as an independent lithological parameter which may be used for lithostratigraphic correlation. Comparison between corresponding plug and whole core susceptibility values indicates some degree of lateral inhomogeneity in the mineralogy of the core.
