Emplacement and exhumation of the Kuznetsk-Alatau basement (Siberia): implications for the tectonic evolution of the Central Asian Orogenic Belt and sediment supply to the Kuznetsk, Minusa and West Siberian Basins

Abstract

New geochronological data [zircon U/Pb, titanite fission-track (TFT) and apatite fission-track (AFT) dating and apatite (U-Th-Sm)/He thermochronology] and thermal history modelling yield constraints on the development of the granitoid basement of the Kuznetsk-Alatau Mountains, southern Siberia. The final stages of magmatism in the Kuznetsk-Alatau palaeo-island-arc are Late Cambrian, and collision of the arc with Siberia occurred in the Early Ordovician. The basement was exhumed by the Early Devonian. Continuous Devonian–Early Triassic sedimentation filled the adjoining Kuznetsk and Minusa basins and buried (and re-heated) the Kuznetsk-Alatau basement. After initial Pangaea break-up and Siberian flood-basalt magmatism, the basement reached TFT and AFT retention-temperatures in the Middle Triassic and Early Cretaceous, respectively, during denudation-induced cooling.