Improvement of cyclostratigraphic studies by processing of high-resolution magnetic susceptibility logging: Example of PEP1002 borehole (Bure, Meuse, France)

Logging opens wide paths for cyclostratigraphic studies of sedimentary successions. In clay-dominated rocks, magnetic susceptibility (MS) is very informative and the quality of the results can be further enhanced by deconvolution, where the deformation of the original susceptibility versus depth variation by the instrument is filtered out by its impulse response (thin layer response). This is illustrated by processing the data acquired in the PEP1002 borehole (Bure, Meuse, France) using two coils 0.25 m apart where high-frequency, 0.5 to 0.8 m, period precession cycles (21 kyr) can be identified, as well as the 2.5 to 4 m period eccentricity (95 kyr) ones.