Tectono-thermal event is a common geological phenomenon of deep-sourced fluid upwelling caused by tectonic deformation and dislocation of lithospheric plate triggered by strong tectonic activity in deep earth.In order to discuss the relationship between tectono-thermal event and oil and gas,taking Sichuan Basin as an example,systemic method was used to investigate the influence of tectono-thermal event on hydrocarbon accumulation conditions.The results show that a tectono-thermal event induced by upwelling of the Emeishan mantle plume and extension of the southern Qinling oceanic lithospheric plate dramatically happened in Sichuan Basin and its adjacent areas in late Paleozoic,which had an important impact on hydrocarbon accumulation conditions.It is mainly shown as follows:① Various types of oil and gas reservoirs were formed,including the igneous rock reservoirs associated with volcanic eruption,the carbonate karst reservoirs of the Middle Permian Maokou formation associated with regional crustal uplift,and the reef-shoal limestone reservoirs and the tectono-hydrothermal dolomite reservoirs related to tectonic extension,etc.(2)The high paleo-geothermal anomaly is rapidly produced,which accelerates the mature evolution process of Sinian-Middle Permian source rocks.(3)The driving force and pathways for oil and gas migration are provided.④ The phase/state transformation of oil and gas is promoted.(5)The hydrocarbon accumulation times are pushed ahead,and the retention duration of paleo-reservoirs is prolonged,which increases the risks reformed and damaged by late tectonic movements.In conclusion,the Late Paleozoic tectono-thermal event has momentous impacts on hydrocarbon accumulation conditions,accumulation processes,phase transformation and preservation of Sinian-Lower Triassic Systems in Sichuan Basin.
late paleozoictectono-thermal eventhydrocarbon accumulationSichuan Basin
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