slides

An integrated magnetic susceptibility anisotropy (AMS) and structural geological study on Cenozoic clay rich sediments from the Transdanubian Range

Abstract

Systematic structural measurements and simultaneous measurements of anisotropy of magnetic susceptibiliy (AMS) were carried out on Cenozoic clay rich deposits from the Transdanubian Range, southern part of the Alcapa Unit. The aim was to reconstruct the structural evolution for the studied area and establish the connection of the stress fields and the fabric of the sediments by studying outcrops with both methods. The measurements of AMS revealed dominant foliation with weak lineation for Oligocene and Eocene sediments. The directions of AMS lineation are aligned with the directions of the extension of the oldest deformation phase having affected the given outcrops. This relatively oldest phase is mostly extensional or strike-slip type deformation with NE-SW to NNE-SSW extensional axis. At present we are working on the problem of establishing a statistical relationship between the AMS lineation and direction of the extension calculated from microtectonic measurements The magnetic fabrics of the studied Late Miocene sediments are foliated without consistent lineations on locality level, which means that they do not reveal any sign of tectonic deformation. However, the brittle structural elements, mainly joints and small-displacement faults without striae, in few late Miocene outcrops indicate more than two stress fields although their direction and character are relatively poorly constrained. All of the localities exhibit pure compression, transpression or a strike-slip stress field (this latest is always the youngest one). This coincide with other independent data (such as morphotectonics, space geodetic data (GPS), recent stress data), which prove the inversion of the Pannonian Basin. Financial support from Hungarian Scientific Research Fund (project no. OTKA K 105245 and 81530) is acknowledged

    Similar works