100Ma——塔里木盆地演化的重要周期

运用沉积盆地波动分析方法对塔里木盆地典型井的周期分析表明，塔里木盆地在其地质历史时期１００Ｍａ的周期是很明显的，自寒武纪以来共经历了４个完整的周期，每一完整周期都由正相位和负相位两个半周期所组成，而第三纪为第Ⅴ个周期的正相位阶段。该周期控制了盆地内的沉积与剥蚀的过程及成藏旋回，并至少控制了古生代的反转构造。对沉积与剥蚀过程的控制作用表现在周期波正相位和负相位分别对应于沉积期和剥蚀期；对含油气系统的控制作用表现在：第Ⅰ个周期波构成以早古生代地层为主体的含油气系统，第Ⅱ个周期波至第Ⅳ个周期波构成以晚古生代至中生代地层为主体的含油气系统，第Ⅴ个周期的正相位阶段构成以新生代地层为主体的含油气系统；对反转构造的控制作用表现在：正相位Ⅰ（寒武纪—早奥陶世）和正相位Ⅱ（晚泥盆世晚期—晚石炭世早期）为伸展构造体制，负相位Ⅰ（中奥陶世—晚泥盆世早期）与负相位Ⅱ（晚石炭世晚期—早二叠世早期）为挤压构造体制。塔里木盆地演化具有１００Ｍａ周期的原因与古天山洋、古昆仑洋及特提斯洋的Ｂ型俯冲触发的地幔羽的上升流及地块的拼贴导致的地幔羽的休眠状态息息相关，从而周期性地控制了塔里木盆地内的沉积与剥蚀过程、成藏旋回及反转构造。

100Ma AN IMPORTANT INTERVAL IN THE EVOLUTION OF THE TARIM BASIN

Based on the periodicity analysis for the typical wells of the Tarim basin with the method of wave analysis, the periods of 100 Ma can be seen in existence obviously from Cambrian, there are four complete periods and each of them is composed of half period of positive phase and half period of negative phase. Tertiary is a positive phase of the fifth period. All of the processes no matter what of deposition, erosion or entrapment cycles and, at least the inversion tectonics of Paleozoic, are all controlled by the 100Ma period. The controlling effects of the period on the processes of deposition and erosion are confirmed by the facts that the positive and negative phases are wholly corresponding to the depositional and erosional ages, respectively. The controlling effects of the period on petroleum systems are shown by the fact that the petroleum system of the Early Paleozoic is made up of the first periodic wave, the petroleum systems from the Late Paleozoic to the Mesozoic consist of the second to fourth periodic waves, and the petroleum system of Cenozoic is made up of the positive phase of the fifth period. Controlling effects of the inversion tectonics can be recognized by that the positive phases Ⅰ (Cambrian to the Early Ordovician) and Ⅱ (the end of the Late Devonian to the beginning of Late Carboniferous) belonged to the extensional tectonic regime, and negative phases Ⅰ (the Middle Ordovician to the early time of Late Devonian) and Ⅱ (the end of the Late Carboniferous to the beginning of Late Permian) belonged to the compressional tectonic regime. The reasons for the existence of a period of 100Ma in the evolution process of the Tarim basin may be attributed to the ascending plume triggered by B type subduction of Paleo Tianshan Ocean, Paleo Kunlun Ocean and Tethys Ocean, and the dormant state of plume resulted from block matching. So the period controls over not only the process of deposition and erosion, but also the entrapment cycle and inversion tectonics.