川东北地区沉积波动特征与油气成藏

Sedimentary Characteristics and Hydrocarbon Accumulation in Northeast Sichuan Basin

川东北地区是上扬子板块北缘的中新生代含油气盆地,具有复杂的构造和成藏历史。采用沉积波动方法对其进行分析,研究了川东北地区沉积波动过程的主要周期,得出控制该区沉积波动的5个周期分别为760、220、100、352、0 Ma,以及存在2个周期为200 Ma的一级波动周期和4个周期为100 Ma的二级波动周期。通过分析二级波动周期与成藏旋回的关系,将该区分为3个成藏旋回。

Northeast Sichuan Basin is a Mesozoic--Cenozoic basin in north margin of the Yangtse plate, which has a complex tectonic background and hydrocarbon accumulation history. By means of the analysis method of wave processes, major cycles of sedimentary wave process in this basin have been studied. The results show that there are five-order cycles corresponding to 760 Ma, 220 Ma, 100 Ma, 35 Ma and 20 Ma respectively, and the two first-order sedimentary cycles（200 Ma） and four second-order sedimentary cycles. The authors find that the second-order sedimentary cycles are well matched with reservoir formation cycles through studying the relationship between second-order sedimentary cycles and reservoir formation cycles, and dividethree reservoir formation cycles in this basin.