This paper presents a new approach based on Anisotropy of Magnetic Susceptibility, that aims to define the spatial evolution of deformation in shales through the analysis of non-oriented fragments. This technique facilitates and speeds up sampling and measurements, and consequently, hundreds of samples can be analyzed in a few weeks of work. The proposed procedure is here applied to a high-resolution study of deformation in the Eocene shales of the South Pyrenean basin. This study shows that it is possible to accurately measure small irregularly shaped fragments of a few grams. Scalar data that are not dependent on the orientation of the sample are studied. The magnetic fabrics indicate a deformation gradient in the foot-wall of a major thrust, for which a five-stage development is proposed. On the other hand, gradient heterogeneities reveal non-previously detected tectonic features, such as blind thrusts. This technique can be applied both to surface geology and cuttings from boreholes, and its sound results indicate that the study of the magnetic fabric is particularly sensitive and accurate for understanding the process and state of deformation in shales.

本文提出了一种基于磁化率各向异性的新方法，旨在通过分析非定向碎片来定义页岩变形的空间演化。这种技术促进并加快了采样和测量，因此，可以在几周的工作中分析数百个样本。此处提出的程序应用于南比利牛斯盆地始新世页岩变形的高分辨率研究。这项研究表明，可以准确测量几克的不规则形状的小碎片。研究不依赖于样本方向的标量数据。磁性织物表明主推力下壁的变形梯度，为此提出了五阶段发展。另一方面，梯度异质性揭示了以前未检测到的构造特征，例如盲推力。该技术可应用于地表地质和钻孔岩屑，其良好的结果表明磁性结构的研究对于了解页岩变形过程和状态特别敏感和准确。