松辽盆地白垩系青山口阶界线层型剖面研究  

BOUNDARY STRATOTYPE OF THE CRETACEOUS QINGSHANKOUAN STAGE IN THE SONGLIAO BASIN

作　　者：韩刚[1] 张文婧[2] 黄清华[2] 万晓樵[3] 贺怀宇[4] 

机构地区：[1]东北石油大学地球科学学院,黑龙江大庆163318 [2]大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712 [3]中国地质大学地球科学与资源学院,北京100083 [4]中国科学院地质与地球物理研究所,北京100029

出　　处：《地层学杂志》2012年第3期569-578,共10页Journal of Stratigraphy

基　　金：国家重点基础研究发展计划(973)项目(2006CB701403);国家自然科学基金项目(No.40802012)资助

摘　　要：茂206井是中国白垩纪大陆科学钻探工程井,全井获取了青山口阶497.02m的岩芯资料。茂206井青山口阶为典型的湖相沉积,它具有相对高的有机碳、无机碳稳定同位素,表示当时古湖泊具有较高的生产力;同时在青山口阶下部具有高的规则甾烷/藿烷比值和伽马蜡烷/C30藿烷比值以及低的重排甾烷/常规甾烷比值,表示当时的古湖泊曾发生过藻类勃发事件、水体分层事件和缺氧事件,由此导致了青山口阶优质烃源岩的形成。青山口阶底部出现的一些具重要时代意义的被子植物花粉Cranwellia,Lythraites,Complexiopollis,Borealipollis等,显示青山口阶具有晚白垩世土仑期以后的被子植物花粉色彩,以及湖相沉积岩夹层中的火山灰(斑脱岩)锆石U-Pb年龄也证实了青山口阶底界已属土仑期,其顶界已进入康尼亚克期。The Well Mao 206 was an engineering well for the China Cretaceous Continental Scientific Drilling Program. The well recovered 497.02 meters of drill core. The Qingshankou Formation from Well Mao 206 consists of typical lacustrine sediments with high organic carbon contents and carbonate isotope values, indicating a high level of bioproductivity at that time. The sediments are characterized by a relatively high ratio of regular sterane to bionorhopane and a high ratio of gammacerane to C30 bionorhopane, along with an especially low ratio of diasteranes to conventional sterane at the bottom of Qingshankou Formation. These organic geochemical proxies indicate that algal bloom events, salinity stratification events, and anoxic events might have occurred in this Cretaceous lake, resulting in the formation of organic-rich source rocks. Angiosperm pollens at the bottom of Qingshankou Formation, such as-Cranwellia, Lythraites, Complexiopollis, Borealipollis etc. , has significant biostratigraphic significance, indicating that the Qing- shankou Formation is probably Upper Cretaceous deposits,and bentonite zircon U-Pb ages of the lake sedi- ments have also confirmed that the age of the basal Qingshankou Formation in the Songliao Basin is Turonian rather than Cenomanian.

关 键 词：年代地层 生物地层 青山口阶 白垩系 松辽盆地 

分 类 号：P534.53[天文地球—古生物学与地层学]