博格达山周缘中二叠统芦草沟组与红雁池组沉积特征及演化

通过对博格达山周缘典型露头剖面的芦草沟组与红雁池组进行详细观察和精细测量,结合柴窝堡凹陷内的钻测井、岩芯资料,详细分析了该区的地层特征、沉积相类型及分布特征,进一步探讨了芦草沟组和红雁池的沉积演化过程。研究结果表明:芦草沟组与红雁池组自下而上均可划分为一段、二段和三段,两个组的地层在柴窝堡凹陷内保留相对完整,而在博格达山山前剥蚀较严重,不同地区残留厚度不一;芦草沟组至红雁池组为一个湖侵到湖退的沉积过程,芦草沟组一段、二段主要发育近岸水下扇中扇和外扇,芦草沟组三段以半深湖-深湖沉积为主,红雁池组一段、二段以扇三角洲前缘、滩坝和滨浅湖沉积为主,红雁池组三段主要发育扇三角洲平原。

Sedimentary Characteristics and Evolution of the Middle Permain Lucaogou Formation and Hongyanchi Formation on the Periphery of Bogda Mountain

Through detailed outcrop observation and measurement of the Lucaogou and Hongyanchi Formations on the periphery of the Bogda Mountain, combined with drilling, well-logging and core data from the Chaiwobao depression, the stratigraphic characteristics, sedimentary facies types, and their distribution characteristics were deeply analyzed, furthermore, evolution process of the Lucaogou and Hongyanchi Formations were also discussed in this paper. The re-sults showed that the Lucaogou and Hongyanchi Formations could be both divided into three members, the first through the third from the bottom up, which were kept relatively complete in the Chaiwogou depression whereas the re-sidual thickness were varied in different areas in front of the Bogda Mountain with serious erossion. The sedimentary process of the Lucaogou formation to Hongyanchi Formation was from a lake transgression to a lake regression. The first and second members of Lucaogou Formation were mainly developed in a nearshore subaqueous middle fan and outer fan; the third member of Lucaogou Formation was widely developed in a semi-deep and deep lake. The first and sec-ond members of Hongyanchi Formation were mainly developed in fan delta front, sand bar and beach, and shore shal-low lake whereas the third member was mainly developed in a fan delta plain.