摘要：

综合利用岩心、测井、地震等资料，对内蒙古开鲁盆地陆东凹陷九佛堂组—沙海组层序地层特征及沉积相进行了系统研究。结果表明，陆东凹陷九佛堂组—沙海组可以识别出3个三级层序界面；划分为2个三级层序（九佛堂层序和沙海层序），分别对应九佛堂组和沙海组；识别出4种主要沉积相类型：扇三角洲相、近岸浊积扇相、远岸浊积扇相及湖泊相。在层序格架内，利用钻、测井资料和二维、三维地震资料对沉积体进行分析，并以此为依据，进一步研究了体系域内沉积相平面展布特征及演化规律，最终建立了该时期沉积发育模式：在盆地陡坡带主要发育扇三角洲和近岸浊积扇，在盆地缓坡主要发育扇三角洲和滨浅湖滩坝沉积，在盆地深洼带主要发育远岸浊积扇和风暴岩。

关键词: 开鲁盆地, 陆东凹陷, 下白垩统, 九佛堂组, 沙海组, 层序地层, 沉积相

Abstract:

Comprehensively using cores,logging and seismic data,the sequence stratigraphic features and sedimentary facies of the Lower Cretaceous Jiufotang Formation and Shahai Formation in Ludong Sag,Kailu Basin,have been studied systematically.Three 3rd order sequence boundaries and two 3rd order sequences are identified in the two formations.Four kinds of sedimentary facies are identified,including fan delta,proximal turbidite fan,offshore turbidite fan and lacustrine facies.Within the sequence stratigraphic framework,the depositional bodies are researched by using well drilling,logging,2D and 3D-seismic data.Furthermore, the distribution of sedimentary facies and evolution law in system tracts have been researched,and the depositional model of this period was built.According to the model,fan delta dominately developed on the steep slope,while fan delta and beach bars developed on the gentle slope belt,and off-shore turbidite fan and tempestites developed in the deep depression zones in Ludong Sag.

Key words: Kailu Basin, Ludong Sag, Lower Cretaceous, Jiufotang Formation, Shahai Formation, sequence stratigraphy, sedimentary facies

中图分类号: 

• P539.2