Major active faults of SW Bulgaria: implications of their geometry, kinematics and the regional active stress regime
Published:January 01, 2006
Markos D. Tranos, Vassilis G. Karakostas, Eleftheria E. Papadimitriou, Vladislav N. Kachev, Boyko K. Ranguelov, Dragomir K. Gospodinov, 2006. "Major active faults of SW Bulgaria: implications of their geometry, kinematics and the regional active stress regime", Tectonic Development of the Eastern Mediterranean Region, A. H. F. Robertson, D. Mountrakis
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Southwest Bulgaria is an intracontinental region between the Dinaro-Hellenic and Balkan mountain ranges that has experienced infrequent, but strong and destructive earthquakes. The general geometric and kinematic characteristics of the major faults, mainly the active ones, are investigated, as the seismic activity is insufficient to describe thoroughly the active crustal deformation associated with the faulting. The results suggest a major rupture zone with a length of more than 50 km. The east—west-striking Kochani—Kroupnik— Bansko ‘rupture zone’ was potentially associated with the large 1904 Kroupnik earthquakes, and has been found to transect the region joining the Kochani, Kroupnik and Bansko faults. In addition, a long-term slip rate ranging from 0.14 to 0.7 mm a−1 has been estimated for some large faults in the region using morphotectonic features. The most active faults are normal ones striking WNW—ESE to ENE—WSW, whereas the NNW—SSE- to NW—SE-striking faults tended to act as barriers to the growth of the former faults, as they do not exhibit much indication of recent reactivation. The stress regime determined is extensional with the least principal stress axis (σ3) subhorizontal and oriented north—south. The fact that the active faults show geometric and kinematic characteristics, as well as estimated long-term slip rates, similar to those of the active faults of central and eastern Macedonia and Thrace (Northern Greece) suggests that both of these regions share a single contemporary stress field.
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Tectonic Development of the Eastern Mediterranean Region
The Eastern Mediterranean region is a classic area for the study of tectonic processes and settings related to the development of the Tethyan orogenic belt. The present set of research and synthesis papers by Earth scientist from countries in this region and others provides an up-to-date, interdisciplinary overview of the tectonic development of the Eastern Mediterrenean region from Precambrian to Recent. Key topics include continental rifting, ophiolite genesis and emplacement, continental collision, extensional tectonics, crustal exhumation and intraplate deformation (e.g. active faulting). Alternative tectonic reconstructions of the Tethyan orogen are presented and discussed, with important implications for other regions of the world. The book will be an essential source of information and interpretation for academic researchers (geologists and geophysicists), advanced undergraduates and also for industry professionals, including those concerned with hydrocarbons, minerals and geological hazards (e.g. earthquakes).