Fábricas magnéticas en materiales sin-diapíricos del encajante (N cuenca Vasco-Cantábrica)

Abstract

This work shows the results obtained after the analysis of the Anisotropy of Magnetic Susceptibility (AMS) of 29 sites sampled on Aptian-Albian marls, marly limestones, fine sandstones and lutites. The study area is located on the northern part of the central sector of the Basque-Cantabrian basin. Fifteen sites were sampled on syn-diapiric rocks related to the Bakio and Bermeo diapirs, on their halokinetic sequences, whereas 14 sites were done on rocks from the same age but do not affected by diapir growth in order to compare them. The parameters Km, Pj and T show typical values of weakly deformed rocks and only vary in function of lithology. The magnetic foliation of almost all sites is parallel to bedding, suggesting it reflects depositional and compaction processes. Whereas the orientation of the magnetic lineation, always contained on the bedding plane, varies between sites sampled on the halokinetic sequences and the rest of sites. In detail, in the Bakio diapir, the magnetic lineation is parallel to the diapir flanks suggesting a possible control related to its growth.