The contemporary state of stress and strain at the western pericline of the Greater Caucasus.

Saved in:

Bibliographic Details
Title:	The contemporary state of stress and strain at the western pericline of the Greater Caucasus.
Authors:	Marinin, A.¹ marinin@ifz.ru, Sim, L.¹
Source:	Geotectonics. Sep2015, Vol. 49 Issue 5, p411-424. 14p.
Subject Terms:	Fault zones, Paragenesis, Strain tensors, Strains & stresses (Mechanics), *Axial stresses
Abstract:	We collected materials on geological indicators of paleostresses at the western pericline of the Greater Caucasus mega-anticlinorium and within the large transverse flexure-fault zone (Anapa and Dzhiginka zones) limiting this mega-anticlinorium. Based on the data, we reconstructed local stress states in different tectonic zones. The reconstructed local stresses showed a considerable variation of the orientations axes of principal stress near the two zones. In a site adjacent to the flexure-fault zone and located near the western pericline of the Greater Caucasus mega-anticlinorium, the detachment systems of northeastern (NE-SW) strike are determined. Additionally, field structural studies proved elongation in the northwestern (NW-SE) direction. This was also verified by the reconstruction of orientations of minimum compression stress axes (maximum deviatory tension) implemented by cataclastic analysis of structural-kinematic information on the movements of the fault planes (tectonic cracks and minor ruptures). We found a well-expressed multistage regime of the northwestern (NW-SE) tension within the limits of the Semisam anticline. Tension deformations (along the axis of the main folded structure) are manifested in structures of different scales; the values of relative elongation are defined for some of them. At the western pericline of the Greater Caucasus mega-anticlinorium, in the Miocene deposits, a north-south (NNW) compression regime with steep inclinations of axes of maximum compression stresses was identified. In the boundary zone between the Northwestern Caucasus and transverse Kerch-Taman trough, an alteration of the orientations of main axes of normal stresses was found. These changes led to the replacement of horizontal-compression and horizontalshear (with a NE-oriented compression) settings, which are predominant in the Caucasus, with settings of horizontal tension (with steep NNW-oriented compression axes). [ABSTRACT FROM AUTHOR]
Database:	Energy & Power Source

Description
Abstract:	We collected materials on geological indicators of paleostresses at the western pericline of the Greater Caucasus mega-anticlinorium and within the large transverse flexure-fault zone (Anapa and Dzhiginka zones) limiting this mega-anticlinorium. Based on the data, we reconstructed local stress states in different tectonic zones. The reconstructed local stresses showed a considerable variation of the orientations axes of principal stress near the two zones. In a site adjacent to the flexure-fault zone and located near the western pericline of the Greater Caucasus mega-anticlinorium, the detachment systems of northeastern (NE-SW) strike are determined. Additionally, field structural studies proved elongation in the northwestern (NW-SE) direction. This was also verified by the reconstruction of orientations of minimum compression stress axes (maximum deviatory tension) implemented by cataclastic analysis of structural-kinematic information on the movements of the fault planes (tectonic cracks and minor ruptures). We found a well-expressed multistage regime of the northwestern (NW-SE) tension within the limits of the Semisam anticline. Tension deformations (along the axis of the main folded structure) are manifested in structures of different scales; the values of relative elongation are defined for some of them. At the western pericline of the Greater Caucasus mega-anticlinorium, in the Miocene deposits, a north-south (NNW) compression regime with steep inclinations of axes of maximum compression stresses was identified. In the boundary zone between the Northwestern Caucasus and transverse Kerch-Taman trough, an alteration of the orientations of main axes of normal stresses was found. These changes led to the replacement of horizontal-compression and horizontalshear (with a NE-oriented compression) settings, which are predominant in the Caucasus, with settings of horizontal tension (with steep NNW-oriented compression axes). [ABSTRACT FROM AUTHOR]
ISSN:	00168521
DOI:	10.1134/S0016852115040068