酒西盆地早白垩世沉积特征及原型盆地恢复

Sedimentary characteristics of the Lower Cretaceous and reconstruction of the prototype basin in the Jiuxi Basin

通过对盆地下白垩统各组古流向、砾岩砾石成分等沉积特征的综合分析,结合玉门油田地震、测井、钻井资料,证明早白垩世赤金峡山、黑山并未隆起成山;宽滩山凸起(宽滩山为其一部分)只在下沟组沉积早期露出水面遭受剥蚀。由于规模较小,且呈长轴状沿北东-南西向展布,不足以隔断酒西地区(现今酒西盆地所涵盖的区域)同花海凹陷的联系。酒西盆地早白垩世为一受北西-南东向伸展作用控制的断陷盆地。盆地演化经历了断陷初始阶段、断陷扩展阶段及盆地萎缩消亡阶段,分别对应于下白垩统赤金堡组、下沟组和中沟组沉积时期。

An integrated analysis of depositional characteristics such as paleocurrents and gravel composition of the Lower Cretaceous strata in the Jiuxi Basin, combined with the seismic, logging, and drilling data of Yumen oilfield, proves that Chijinxia mountain and Hei mountain didn＇ t exist in the Early Cretaceous, and the Kuantanshan low uplift （ with Kuantan mountain as a part of it） did not separate Jiuxi Basin from Huahai sag due to its small scale and NE-SW-trending long axis. The researches shows that Jiuxi Basin was a rifted basin controlled mainly by NW-SE extension in the early Cretaceous. The basin experienced three stages during its evolution： initiation,growth and die-out, which correspond to the deposition periods of Chijinbao, Xiagou, and Zhonggou formations respectively.