Abstract: It is of great significance for study of the temporal-spatial coupling of hydrocarbon migration and accumulation with trap formation to investigate the timing and chronology of hydrocarbon charging in multi-stages superimposed basins. This study, firstly, employed the analytic methods of crude oil and oil inclusion molecular geochemistry, single fluid inclusion microspectrofluorimetric and thermal maturity assessment, and microthermistry to determine the timing of hydrocarbon charging in the Ordovician strata of Tahe oilfield. The results show that the hydrocarbons in the Ordovician were charged in three periods. Secondly, the indirect dating method of aqueous inclusion and the direct dating method of stable radioactive isotope of Re-Os and K-Ar were used to establish the chronological sequence: the first charging event took place during the Middle to Late Caledonian (463. 2-414. 9 Ma), the second charging event happened during the Late Hercy-nian (312. 9-268. 8 Ma), and the third charging event occurred during the Himalaya (22-4. 8 Ma). All the three events occurred in the main Tahe oilfield, but only the first and third events developed in the peripheral areas of Tahe oilfield, such as Aiding, Tuoputai and South Tahe areas. Obviously, a deep understanding of the heterogeneity of hydrocarbon charging events and chronology in Tahe oilfield, which were controlled by differential structure evolution, will be helpful for hydrocarbon exploration in the Ordovician of other structural belts of Tarim Basin.

Key words: timing of hydrocarbon charging, chronology, fluid inclusion, Ordovician, Tahe oilfield