Fault systems in multiply deformed regions of Eurasia

Abstract

We have studied the orogenic fragile deformation of the upper Earth's crust of several areas of the Eurasian continent, where deformations have occurred many times -- in the Tian Shan and Altai-Sayan regions of the Central Asian Paleozoic Fold Belt and in the Baltic region in the Fennoscandian Shield (East European Platform). Our processing of data on the trends of more than 4000 faults allows us to identify fault systems and relationships among these fault systems. Changes in the intensity and kinematics of the activity of fault systems in different epochs of deformation of regions are revealed. In the Tien Shan and Altai-Sayan regions, fault movements occurred during Early Paleozoic, Late Paleozoic and Late Cenozoic orogenies. No new fault systems appeared in the Late Cenozoic deformation in the Tien Shan, where only movement along Paleozoic faults that were suitably oriented occurred. In the Altai-Sayan region, we identify the Late Paleozoic associations of fault systems that activated in the recent epoch and the association of fault systems created in the Late Cenozoic. The Fennoscandian Shield shows different fault kinematics in four Early Proterozoic deformational periods. Our method of analysis of associations of fault systems contributes to a~systematization of data on multi-stage deformation in the upper crust of these regions.