Thermal history of the Ordovician in the Tazhong uplift under the constraint of carbonate clumped isotope

Carbonate clumped isotope is a new type of geologic thermometer that has developed in recent years. It can effectively solve the problem that the carbonate sedimentary basins lack commonly used geologic thermometer. Therefore, it takes an important part in the thermal history reconstruction of sedimentary basins. This paper collects the drill cores of Ordovician carbonate rocks in the Tazhong uplift. The thermal evolution paths of the carbonate clumped isotope temperature (T-Delta 47) in the Tazhong uplift are simulated using the first order rate approximation model, and the thermal history of the Tazhong uplift is constrained by the carbonate clumped isotope as well as the equivalent vitrinite reflectance. From this study, it shows that the heat flow in the Tazhong uplift has generally decreased from 60 similar to 70 mW . m(2) in the Ordovician to 40 similar to 50 mW . m(2) in the present. During the Permian, the heat flow peaked briefly to 60 similar to 70 mW . m(2) due to the intrusion of igneous rocks. According to the simulation, the Lower Ordovician in the northern slope belt and the Middle Ordovician in the buried hill structural belt reached the temperature peaks at 160 similar to 170 degrees C and 180 similar to 190 degrees C in the Permian, respectively. While the southern margin of Tazhong uplift only reached the temperature peak at 130 similar to 140 degrees C in the Mesozoic or the present. All of these simulation results reveal that the northern slope belt and the buried hill belt have been significantly affected by the intrusion of igneous rocks, but the southern margin of Tazhong uplift. In general, the research of carbonate clumped isotopes in the field of thermal history is still in an exploratory stage, and it is expected to be further improved in terms of carbonate clumped isotopic rearrangement laws, T-Delta 47 influencing factors and model theory in the future. The application of carbonate clumped isotope will have an increasingly significant impact in the field of thermal history research.