塔里木盆地寒武纪构造演化研究

对塔里木盆地寒武纪早、中、晚3个时期的古水深、沉积速率、构造沉降速率和拉伸系数计算结果表明,塔里木盆地在早寒武世为深度裂陷阶段,中寒武世为裂陷迁移阶段,晚寒武世为台内裂陷阶段,早寒武世与中-晚寒武世的构造差异性十分明显。早寒武世伸展引起的裂陷作用发生在塔东地区,伸展促使该区构造沉降速率远远大于台地相区,形成半深海盆地相环境。中-晚寒武世伸展向台地内部迁移,使台地内部的构造沉降速率远大于盆地相区,而台地内部较高构造沉降速率被更高的沉积速率所补偿,使得这里始终未能出现地貌上的凹地。

The tectonic evolution of Cambrian in Tarim Basin

The paleobathymetry of the three periods of Cambrian was analyzed in this paper,furthermore,the rate of deposition and tectonic subsidence,as well as stretching coefficient for the three periods were systematically calculated.The results indicate three rift stages which is the intense rift stage,the migrating rift stage,and the platform rifted stage,respectively for the early,middle and late Cambrian.There are quite different in tectonic characteristics during the sedimentary period between early Cambrian and middle-late Cambrian.Rifting caused by stretching initially occurred in the eastern Tarim to promote the bathyal environments formed in early Cambrian,where the tectonic subsidence rate is much great than the platform in the center-western Tarim.When to the middle-late Cambrian,the stretching extended to the internal platform in the center-western Tarim,leading to the tectonic subsidence much great than the bathyal environments in the eastern Tarim.However,the high tectonic subsidence rate in the internal platform was compensated by a higher sedimentary deposition rate; therefore a bathyal environment can't be formed in the internal platform during middle-late Cambrian.