松辽盆地上、下白垩统界线划分  

On the division of Upper-Lower Cretaceous boundary in Songliao Basin

作　　者：黄清华[1] 张文婧[1] 贾琼[1] 党毅敏[1] 王平[1] 高宝明[2] 谢磊[3] 

机构地区：[1]大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712 [2]大庆石油管理局电力集团电力营销公司,黑龙江大庆163453 [3]大庆油田有限责任公司大庆钻探工程公司地质录井一公司,黑龙江大庆163411

出　　处：《地学前缘》2009年第6期77-84,共8页Earth Science Frontiers

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(40802012)

摘　　要：松辽盆地白垩纪发育有热河生物群、松花江生物群和明水生物群,表现为三大生物群有序演化与更替。白垩纪中期是松花江生物群发育期,松花江生物群具有明显的地域性色彩,泉头组被子植物化石Trapaangulata、Platanus septentrionalis和孢粉化石Crenwellia、Xinjiangpollis、Quantonenpollenites、Lythraites和Gothanipollis显示其时代已进入晚白垩世。火山岩锆石SHRI MP法U-Pb年龄测试结果表明,营城组的年龄为(115.1±1.2)^(111.1±0.9)Ma,说明营城组已属晚Aptian期至早Albian期。磁性地层学研究表明,登娄库组-姚家组以稳定的正极性为主,仅在登娄库组上部和姚家组下部分别出现一次短暂的反极性事件。青山口阶下部具一套广泛分布富含有机碳的黑色页岩、油页岩沉积,其干酪根碳同位素表现为明显的正向偏移特征,为古湖泊缺氧事件的产物。结合生物、同位素年代、磁性地层研究的结果,认为青山口阶底部缺氧事件层对应于白垩纪古海洋Cenomanian-Turonian期界线缺氧事件,由此,给出的松辽盆地上、下白垩统的界线划分在泉头组和登娄库组之间。The Songliao Basin was a big lake during the mid-Cretaceous,where Jehol,Songhuajiang and Mingshui biotas were developed in the Cretaceous;the organic of the lake expressed the sequence,the explosion and the extinction of the three biotas.The Songhuajiang Biota consisted of ostracodes,conchostracans,bivalves,charophytes,dinoflagellates,palynoflora,angiospermae etc.with distinct regional features.The angiospermae fossils such as Trapa angulata,Platanus septentrionalis,and the angiospermae pollen such as Crenwellia,Xinjiangpollis,Quantonenpollenites,Lythraites,Gothanipollis have been obtained from the Quantou Formation,with the age of the Late Cretaceous.SHRIMP zircon U-Pb ages of nine volcanic rock samples from Yingchen range from（115.1±1.2）Ma to（111.1±0.9）Ma,falling into the Late Aptian to the Early Albian stage.The magnetostratigraphic research indicated that the polarity from the Denglouku to the Yaojia Formation is normal,but twice brief reversed polarity occurred in the Upper Part of the Denglouku Formation and the Lower Part of the Yaojia Formation.The dark shales and oil-shales in the Lower Part of the Qingshankou Formation are of high organic carbon,and positive excursion of kerogen isotopes.It is suggested that the dark shales in the Lower Part of the Qingshankou Formation are the products of the lake anoxic period.Based on the study of biostratigraphy,chronostratigraphy,magnetostratigraphy and event stratigraphy,the Lower/Upper Cretaceous boundary in the Songliao Basin is,therefore,between the Quantou and the Denglouku Formation,instead of between the Quantou and the Qingshankou Formation.

关 键 词：登娄库阶 泉头阶 青山口阶 上、下白垩统界线 松辽盆地 

分 类 号：P534.53[天文地球—古生物学与地层学] P618.13[天文地球—地质学]