HR: 0800h
AN: T21B-0591    [Abstracts]
TI: Paleostress Analysis Applied to Fault-Slip Data from the Southern Margin of the Central European Basin System (CEBS)
AU: * Scheck-Wenderot, M
EM: leni@gfz-potsdam.de
AF: GeoForschungsZentrum Potsdam in der Helmholtz Gemeinschaft, Telegrafenberg, Potsdam, 14473, Germany
AU: Sippel, J
EM: sippel@gfz-potsdam.de
AF: GeoForschungsZentrum Potsdam in der Helmholtz Gemeinschaft, Telegrafenberg, Potsdam, 14473, Germany
AU: Reicherter, K
AF: RWTH Aachen, Lochnerstr. 4-20, Aachen, 52056, Germany
AU: Mazur, S
AF: GETECH Group plc, Kitson House, Elmete Hall, Leeds, LS8 2LJ, United Kingdom
AB: We investigate the paleostress fields which controlled the post-Variscan evolution of the Central European Basin System (CEBS). Therefore, field studies are carried out in the marginal areas of the CEBS where Late Palaeozoic and Mesozoic rocks of the basin fill are present in outcrops bearing the imprints of several deformation phases that affected the basin system since the latest Carboniferous. Field studies including structural analysis, measurement of fault-slip data and careful collection of kinematic indicators provide the data base for this study. In the case of polyphase tectonics, the chronology of successive events is deduced and the total fault population from each site is qualitatively divided into different subsets, each being consistent with one specific stress regime. Since the stratigraphy and evolution of the CEBS are well known, temporal and spatial correlations of paleostress orientations are possible. Beside cross-cutting relationships derived from outcrops, we apply different graphical and numerical methods to separate the faults into homogeneous subsets. Depending on (1) the nature of faults (i.e. neoformed or reactivated), (2) the distribution of fault-slip data and (3) the deformation style, the deviatoric stress tensor is calculated for each subset using either the Numeric Dynamic Analysis or the Multiple Inverse Method. The results are obtained in terms of a reduced stress tensor, consisting of (1) the orientations of the three principal stress axes Sigma1, Sigma2 and Sigma3 with Sigma1>Sigma2>Sigma3 and (2) the ratio of principal stress differences, R =(Sigma2-Sigma3)/(Sigma1-Sigma3) with 1>R>0.
DE: 8004 Dynamics and mechanics of faulting (8118)
DE: 8010 Fractures and faults
SC: Tectonophysics [T]
MN: 2007 Fall Meeting