Plio-Quaternary paleostress regimes and relation to structural developmentin the Kertch-Taman peninsulas (Ukraine and Russia)

In the Kertch-Taman peninsulas, located between the Crimean and NW-Caucasus Mountains, deep troughs developed since Oligocene time. Sediments were sub sequently folded. Folding was associated with thrusting. Paleostress analys es allowed constraint of the tectonic evolution of the area. An extensional event occurred before folding, perhaps related to the trough development. This event was followed by compression associated with Plio-Quaternary fold ing. Stress tensors determined in older rocks in the Crimean and NW-Caucasu s belts are correlated with this regional Plio-Quaternary compression. In d etail, NS compression followed NW-SE compression. This change in direction could be explained by a change of the direction of convergence of the Black Sea Plate with the Scythian Plate. The NW-SE compression induced NE-SW fol ds in the southern part of the peninsulas. The N-S compression corresponds to E-W folds of the northern part, suggesting a northward propagation of th e deformation front. The structural evolution of the Kertch-Taman region is controlled by (1) pre-existing structures, (2) a change in the direction o f compression related to a change of the direction of convergence of the Bl ack Sea with the Scythian Plate and (3) the northward propagation of the co mpressional front with the continuing indentation of the Black Sea block. ( C) 2000 Elsevier Science Ltd. All rights reserved.