Tectonic Characteristic and Origin of Tazhong Uplift, Tarim Basin

This paper presents the analysis on geological characteristics of Tazhong Uplift, such as the configuration and nature of the fault structures, and the aeromagnetic anomaly, etc. The study result shows that Tazhong Uplift presents several large-scale fault belts that mainly extend in three directions: NW, approximate (approx.) EW and NNE. The NW fault belts lie in the north and northwest of the research area; the approx. EW fault belts rest in the south and southeast of the research area, whereas the NNE fault belts are mainly strike-slip faults and cut the NW fault belts into several structural segments. It is concluded that the late Caledonian and the late Hercynian period were the two major forming periods of Tazhong Uplift. In the late Caledonian period, the NW thrust faults developed in Tazhong Uplift under the tectonic compression stress from the southwest Foreland Basin. In the late Hercynian period, the subduction of Altyn Orogenic Belt influenced the central Tarim and generated the approx. EW thrust faults in the central and southern Tazhong Uplift. This subduction also forced the early-formed fault belts into an arc-shape in the central Tazhong Uplift and caused NNE strike-slip faults in the northern Tazhong Uplift. Laterally the tectonic stress decreased from the south to the north. From regional perspective, the fault belts diverge to the west and converge to the east.