Applications of tectonic geomorphology for deciphering active deformation in the Pannonian Basin, Hungary

摘要

Tectonic geomorphology has proven to be a useful tool for identifying and quantifying active and geologically recent tectonic deformation. Some of these techniques have been applied within the Pannonian Basin, but the region presents some pat ticular challenges to deciphering the pattern of Quaternary deformation. In the Pannonian Basin, Neogene basin-forming extension has been supplanted by transpression. Although the magnitude of shortening appears to be minor relative to total extension, compressional structures appear to be the primary influence on both petroleum accumulation and topographic relief within the basin In many geological settings around the world, the field of tectonic geomorphology has provided tools for evaluating the nature, pattern, and rates of active deformation. In western Hungary, we have completed morphometric analyses to assess the likelihood of active motion on petroleum-producing anticlinal structures in the region. South of the Zala River, fluvial terraces were mapped and measured over the crests of these structures. The present-day terrace geometry is consistent with anticlinal warping during the Quaternary, and SL indices and Transverse Topographic Symmetry Factors were calculated for the major drainages in the region. These morphometric tests suggest broad, slow uplift and westward propagation of the Budafa-Lovaszi anticlines as well as possible incipient motion across two parallel structures. The incentive for future geomorphic work remains strong, Geomorphic mapping of recent deformation could help answer questions regarding thermal history, migration, and over pressuring in Hungarian oil fields, and the timing and rates of deformation in the Pannonian Basin are important for assessing seismic hazard and nuclear safety in the region.