海拉尔盆地乌尔逊—贝尔凹陷白垩系沉积相配置及演化研究

The research of sedimentary facies configuration and their evolution in Cretaceous of Wuerxun-Beier sag in Hailaer Basin

在等时地层格架的基础上,通过对海拉尔盆地乌尔逊—贝尔凹陷130口钻井岩心的精细描述、薄片鉴定和电测曲线分析,根据岩石类型组合、沉积结构和构造以及沉积序列等沉积相标志在海拉尔盆地下白垩统识别出冲积扇、扇三角洲、曲流河三角洲、湖泊和湖底扇5种沉积相类型,进—步划分出15种亚相以及21种微相类型。铜钵庙组沉积时期盆地为填平补齐特征,主要为冲积扇—扇三角洲—滨浅湖沉积体系充填。南一段下部、中部沉积时期盆地为"泛盆"特征,厚度小、范围广,全区稳定分布,充填物由冲积扇一扇三角洲一湖泊沉积体系过渡到辫状河三角洲一湖泊沉积体系。南一段上和南二段沉积时期盆地为"复式小型断陷湖盆",沉积充填以辫状河三角洲为主。大磨拐河组的沉积充填以辫状河、曲流河三角洲共存为特征。

In the base of chronostratigraphic framwork,through cores fine descriptions,chips identification and electric logging curve analysis of 130 drillings in WuerxunBeier sag of Hailaer Basin,according to rock types combination,sedimentary structure and tectonic and sedimentary facies, 5 sedimentary facie types including alluvial fan,fan delta,meandering river delta,lakes and sublacustrine fan,can be recognized in the purpose layers of Lower Cretaceous in Hailaer Basin,then 15 subfacies and 21 microfacies types can be further identified.During the deposition period of Tongbomiao group,the basin was to fill and polish for features,and the main sedimentary morphology of fillings was alluvial fanfan deltalittoral and shallow lake sedimentary system.During the deposition period of the lower,central in Nanyi segment,the basin was to “Pan Basin” for features,of small thickness,range and the stable distributions,and the sedimentary morphology of fillings was from alluvial fanbraided fan deltalakes sedimentary system to the braided river deltalake sedimentary system.During the higher Nanyi segment and Naner,the basin was “double entry small faulted basin”,and the main sedimentary morphology of fillings was braided delta.The characteristic of the sedimentary filling in Damoguaihe group was the coexistence of braided fluvial river and meandering river delta.