Home – Home – Jornals – Russian Geology and Geophysics 2002 number 2

The Late Paleozoic structure and evolution of the junction between Gorny Altai and West Sayan is considered on the basis of geochronology and structural analysis by morphological, stereogeometric, and microstructural methods. The distinguished evolution stages of the region (Early-Middle Devonian, Late Devonian-Early Carboniferous, and Permian) fit the general geodynamic setting of the Altai-Sayan folded area. The Early-Middle Devonian stage was marked by intrusion of the Altyntauss granitoids into greenschist rocks. During the Late Devonian-Early Carboniferous stage, the Teletskoe shear zone was initiated along the eastern margin of the Altyntauss pluton. The formation of the shear zone was accompanied by strike-slip and thrust faulting under NW-SE compression and corresponds to the stage of collision between Siberia and the Altai-Mongolian terrane. According to new data, the northern part of the shear zone may have been produced by thrusting that acted simultaneously with left-lateral strike-slip motions on the major fault. The amount of horizontal displacement is estimated at about 80 km. The Permian stage corresponds to the Kazakhstan-Siberia collision and was associated with the formation of the North Sayan strike-slip fault under WE compression, with the right-lateral slip of about 30 km. The North Sayan fault truncates and deforms the Late Devonian-Early Carboniferous structure.