川西盆地演化及盆地叠合特征研究

摘要

The western Sichuan basin is located in the eastern margin of Songpan-Canze tectonic zone of Tibetan Plateau. Since Sinian, the western Sichuan basin has been involved into two evolution histories, including the basin evolutions of both marine facies and terrestrial facies. The development for the terrestrial facies basin of the western Sichuan basin has very close relationship with the formation and evolution of Songpan-Ganze tectonic zone and Longmenshan orogenic belt Since Late Triassic, the western Sichuan basin has experienced the coupling of basin and range, as well as the coupling of basin and mountain with Songpan-Ganze tectonic zone and Longmenshan orogenic belt, which resulted in the complex superimposed basin strata with multiple evolution histories. Different basin characteristics and types have been shown in different geological times. In summary, there are four different basin evolution developments, consisting of stable craton marine facies basin (Sinian-Mid Triassic) , alternate marine and terrestrial facies downfaulted basin (Xujiahe FM I-Xujiahe FM III of Upper Triassic), terrestrial depressed basin ( Xujiahe FM IV of Upper Triassic-Mid of Jurassic) , and foreland basin (Upper Jurassic-present) , which contributes to the superimposed strata features of the western Sichuan basin with four evolution periods.%川西盆地位于青藏高原松潘甘孜构造带东缘龙门山前陆地带,是四川盆地的一部分.自震旦纪以来,川西盆地经历了海相盆地与陆相盆地两个时期的演化,其中陆相盆地演化与松潘-甘孜构造带及龙门山的形成发展密切相关.晚三叠世以来,川西盆地与松潘-甘孜构造带、龙门山构造带之间经历了盆岭耦合与盆山耦合两期构造动力学演化过程,形成了结构复杂、多期演化的叠合盆地,其盆地性质、类型在不同地质时期各不相同.总的说来,川西盆地经历稳定克拉通海盆发展时期(震旦纪-中三叠世)、海陆交互相断陷盆地发展时期(上三叠世须家河组一段-须家河组三段)、陆相坳陷盆地发展时期(须家河组四段-中侏罗纪世)、前陆盆地发展时期(晚侏罗世-现今),最终形成了4期单型盆地的有序叠置.