Comparison of methods to reconstruct paleostress regimes in the NW-Greater Caucasus fold-and-thrust belt

Abstract

Two groups of researchers have used the same datasets in order to determine paleostress regimes and the corresponding tectonic phases in the northwestern-Greater Caucasus fold-and-thrust belt. The kinematic indicators were inverted by both groups to determine the magnitude and orientation of the tectonic stresses. The Russian group's method is based on the “structural pattern” that developed under a single stress-strain state in a given rock volume. The French group used a fault slip data inversion. Stress fields reconstructed by both groups show similarities. Because the methods are independent, the paleostress fields may reflect natural processes. The best-expressed paleostress field is a NE-SW compression related to the Late Eocene folding and thrusting event. A stress field that may correspond to the latest tectonic phase of the northwestern-Greater Caucasus is characterized by a NNW-SSE striking pressure axis. Other paleostress fields that span from Late Cretaceous to present-day are also reconstructed by both groups.