New data on the structure of the Kas Block in the basement of the West Siberian Plate

Crustal structure of the Siberian craton and the West Siberian basin: An appraisal of existing seismic data

“…Topography of the West Siberian basin (WSB) and the Siberian craton (SC) based on ETOPO1 (Amante and Eakins, 2009). The map shows the boundaries of the WSB and the SC, the known and suspected Proterozoic and Paleozoic rift-graben structures (after Aplonov, 1995;Pavlov, 1995;Surkov and Smirnov, 2003;Zonenshain et al, 1990) of the crustal seismic models (Table 1). Consequently, the resolution of the crustal structure significantly differs between and even along the PNE profiles (Figs.…”

Geodynamic Model of the Neoproterozoic Evolution of the Yenisei Paleosubduction Zone (Western Margin of the Siberian Craton), Russia

“…The existence of the Middle Neoproterozoic Isakovka and adjacent Predivinsk island-arc systems to the west of the Siberian Craton at the latitudes of the Yenisei Ridge was substantiated in [3,14,17,18,36]. Study of the Isakovka ophiolite belt allowed the Late Neoproterozoic stage of the formation of the Paleo-Asian Ocean to be reconstructed [1,3,12,14,18,26,28,36]. The absolute ages of the rock complexes within the island-arc system range from 700 to 640 Ma [3,4,14,18].…”

“…Based on ophiolites (as an indicator of paleogeodynamic settings characterizing fragments of ancient oceanic crust), as well as paleomagnetic data [4], it was presumed that the oceanic basin originated west (in present-day coordinates) of the Yenisei Ridge at the Mesoproterozoic-Neoproterozoic boundary. Opening of the ocean basin was possibly associated with the evolution of the Rodinia [28,[30][31][32][33][34]. During this period, rupture of the supercontinental crust and parting of its fragments in the intermediate zone between Siberia and Laurentia resulted in the formation of tectonic blocks and, later, a spreading zone, typical oceanic crust, and a subduction zone with a system of island arcs, back-arc basins, and terranes (microcontinents).…”

“…The junction zone of the Pre-Mesozoic basement complexes of the West Siberian Plate with the Yenisei Ridge has long attracted the attention of geologists and geophysicists as a testing ground for deciphering the nature and paleogeodynamic evolution of the Yenisei tectonic belt on the western boundary of the Siberian Craton and the Paleo-Asian Ocean in the Neoproterozoic [18,22,28,30]. Of particular interest is the zone of pronounced positive magnetic anomalies about 40 km in width, which stretches subparallel to the western margin of the Siberian Platform for hundreds of kilometers along the Yenisei River.…”

“…Of particular interest is the zone of pronounced positive magnetic anomalies about 40 km in width, which stretches subparallel to the western margin of the Siberian Platform for hundreds of kilometers along the Yenisei River. The zone is confined to the western flank of the Sayan-Yenisei accretionary belt and to its northern continuation, the Yenisei tectonic belt; it is conventionally considered [4,14,17,18,26,28,36,40] a collisional accretionary system on the margin of the Siberian Platform (Fig. 1).…”