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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JK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 sequence of Jurassic-Cretaceous boundary of Zhangjiagou in Luanping basin is continuous sedimentary shore-shallow lake-semi-deep lake sequence, with abundant fossils in both orthodox and leaf-extremity. It is an ideal layer type of continental J K boundary Candidate profile. Based on the comprehensive study of the Late Jurassic and Early Cretaceous ostracods, the association of leaf-limbs, sedimentology and genetic stratigraphy, it is considered that the boundary of the continental Jurassic-Cretaceous biogenic strata is dominated by the Luanpingella The disappearance of the actress Cypridea, the disappearance of the Nestoria, Pseudograpta and Keratestheria, and the emergence of Eosestheria, fan delta plain or frontal subfacies or the end of the sub-facies and microfacies. Research and definition of continental boundary strata Natural imperfections in biofacies different from marine basins and terrestrial environments can be precisely defined by stratigraphic frameworks and sedimentary sub-micro-facies sequences, compensated for in contrast, and should be included in continental boundary strata In the definition.