燕山地区新元古界青白口系沉积层序与地层格架研究

燕山地区是中国新元古界青白口系出露最好、层序较为完整的地区。从沉积特征研究入手,确定了各种沉积相、微相及沉积序列,在区内青白口系划分出4种沉积体系及5种沉积相、12种沉积亚相、16种微相。对副层序的主要类型及其特征进行了分析,结合层序界面和最大海泛面的研究,将区内青白口系划分出3个层序。在层序划分和对比基础上建立了燕山地区青白口纪的地层沉积格架并对其古地理演化进行了探讨。认为燕山青白口纪的沉积为华北陆块上真正的盖层沉积。

Sedimentary sequence and stratigraphic framework of the Neoproterozoic Qingbaikou system in the Yanshan region,North China

The Yanshan region is one of the regions where the Neoproterozoic Qingbaikou system is well developed. This paper deals mainly with the sedimentology and sequence stratigraphy of the Qingbaikou system in the area. An analysis of the sedimentary features reveals that 4 sedimentary systems, 5 sedimentary facies, 12 subfacies and 16 microfacies are present. From the main types and characters of parasequences, integrated with the study of sequence boundary and maximum-flooding surface, the Qingbaikou system in the region is divided into 3 third-order sequences. Based on the study and correlation of sequences, the stratigraphic framework of the Qingbaikou system of the Yanshan region is set up, and the evolution of paleogeography is discussed. It is suggested that the deposition of the Qingbaikou system in the Yanshan region represents the cover of the North China block.