Heat flow history, tectono-sedimentary evolution and thermal events of the Jianghan basin
江汉盆地热流史、沉积构造演化与热事件

Jianghan basin is one of the significant domains of the hydrocarbon exploration of the Pre-cenozoic marine basins in China.The thermal history is the main factor of controlling the thermal maturation of the source rocks in a basin.Based on the paleo-thermometric indicator of vitrinite reflectance(Ro),the thermal history is reconstructed.The results show that the basal heat flow was relatively low(50 ~55 mW/m2) before Indosinian movement.From the late Indosinian to early Yanshanian episode,however,the heat flow was elevated within the whole basin.The heat flows reached their maximum values of ~72 mW/m2 at about 157 Ma in the north of the Qianbei Fault and 71~76 mW/m2 at around 43Ma in the south of the Qianbei Fault,respectively.Since the late Himalayan period,the heat flow decreased quickly and the basin was cooled consequently.The heat flow history,tectono-sedimentary evolution and magmatic activities of the basin were mutually coupled.Jianghan basin was a stable craton with weak magmatic movements before the Indosinian movement as a result,,the heat flows were characterized by low values.During the late Indosinian-early Yanshanian period,the structural movements became more intensive and the heat flows were elevated simultaneously.During the middle Yanshanian period,the intensity of the magmatic activities controlled the heat flow which was decreasing in the north and increasing in the south of the basin.Since the late Himalayan epoch,The Jianghan basin has been subjected a deposition withering period companied by a cooling episode.