冀北滦平陆相侏罗—白垩系生物地层界线及候选层型研究进展  

Advances in the study of non-marine Jurassic-Cretaceous biostratigraphi cal boundary and candidate stratotype in Luanping basin,northern Hebei

作　　者：柳永清[1] 庞其清[2] 李佩贤[1] 田树刚[1] 牛绍武[3] 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]石家庄经济学院资源环境系,河北石家庄050031 [3]天津地质矿产研究所,天津300170

出　　处：《地质通报》2002年第3期176-180,共5页Geological Bulletin of China

基　　金：中国地质科学院地质调查项目"中国地层标志化石及重点层型剖面"(DKD2001019)资助。

摘　　要：滦平盆地张家沟侏罗—白垩系界线上下为连续沉积的滨浅湖—半深湖序列,介形类和叶肢介类化石丰富,是中国陆相J\K界线理想的层型候选剖面。通过晚侏罗世和早白垩世介形类、叶肢介生物组合及沉积学与成因地层学的综合研究,认为陆相侏罗—白垩系生物地层界线以介形类大个体滦平介Luanpingella的消失、女星介Cypridea的出现,叶肢介Nestoria、Pseudograpta及Keratestheria等的消失以及Eosestheria的始现,扇三角洲平原或前缘亚相或等同亚、微相带的结束为标志。陆相界线层型研究和定义异于海相盆地,陆相环境生物化石的自然缺欠可以通过地层格架建立及沉积亚微相序列高精度地划分、对比予以弥补,并应纳入陆相界线层型的定义中。The Jurassic-Cretaceous Dabeigou and Dadianzi Fms ,in Luanping basin,is typical and no hia-tus non-marine depositional succession,within it Jehol fauna is founded,around the northern Hebei and western Liaoning.Dabeigou and Dadianzi Fms at Zhangjiagou of Luanping basin is characterized by contin-uning terrestrial lake deposition from beach to deep lake subfacies,which is considered as an ideal candidate section for stratotype and ostracoda and conchostracans are prevailing biota within it.On the basis of sedi-mentary facies and successions ,ostracoda and conchostracans biota,herein is given a conclusion to the Jurassic-Cretaceous biostratigraphical boundary and stratotype.The boundary is marked by the disappear of Luanpingella,Nestoria?Pseudograpta and Keratestheria,and first occurrence of Cypridea and Eosestheria,and the top part of fan-delta front subfacies is also another marker for the boundary.

关 键 词：滦平盆地 侏罗-白垩系 生物地层 界线 候选层型 河北 介形类 叶肢介类 

分 类 号：Q915.652[天文地球—古生物学与地层学] Q915.653[生物学—古生物学]