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四川盆地西缘分为龙门山分区和四川盆地分区。已有的地层区划方案均对两大分区采用一条绝然的界限,忽略了盆地西缘原地地层系统与外来地层系统之间不同的沉积环境及构造演化模式。认为在两个分区之间并没有绝然的界线,而是以组成龙门山的三个主要推覆体东缘的断裂为主要界线,但将该界线以东中小飞来峰地层系统归属于龙门山分区,而将介于该界线与中小飞来峰之间的由于飞来峰与主体脱离而暴露的原地地层系统归属于四川盆地分区。龙门山分区可进一步划分为三个小区,分别包含一个大型推覆体及若干中小推覆体或飞来峰,反映了龙门山各段不同的隆升时间及沉积特征。将四川盆地分区进一步划分为西南小区和西北小区,主要以上白垩统及其以上地层是否发育相区别。
The western edge of Sichuan Basin is divided into Longmenshan sub-region and Sichuan Basin sub-region. The existing stratigraphic zoning schemes all adopt an absolute limit to the two major subregions, ignoring the different depositional environments and tectonic evolution patterns between the inland stratigraphic system and the alien stratigraphic system in the western margin of the basin. It is believed that there is no clear boundary between the two subregions. Instead, the main boundary of the east edge of the three main nappe bodies that make up Longmen Shan is the main boundary line. However, this boundary line belongs to the gantry Mountain subregion, while the in situ stratigraphic system between the boundary line and the small and medium-sized flying peak due to the departure of the flying peak and the main body belongs to the Sichuan Basin subregion. The Longmenshan subregion can be further divided into three subdivisions, each containing a large nappe and a number of small and medium-sized thrusting bodies or flying peaks, which reflect the different uplift time and depositional characteristics of various segments of the Longmenshan. The division of the Sichuan Basin is further divided into the southwestern area and the northwestern area, mainly because of differences in the development of the Cretaceous and above strata.