Micropaleontology and palaeoclimate during the early Cretaceous in the Lishu depression,Songliao basin,Northeast China  

作　　者：Wei Yan Tailiang Fan Hongyu Wang Chen Zhu Zhiqian Gao Xiangjie Meng Yangzi Sun Fan Yang 

机构地区：[1]School of Energy Resources,China University of Geosciences,Beijing 100083,China [2]Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism,Ministry of Education,China University of Geoscienees,Beijing 100083,China [3]Department of Geosciences,Indiana University Bloomington,Bloomington,47405,USA [4]Exploration and Development Research Institute of Huabei Oilfield,PetroChina,Renqiu,062550,China [5]The Research Institute of CNOOC Shenzhen Branch,Zhuangzhou,Guangdong,510000,China [6]The First Oil Production of SINOPEC North Chino Company,Qingyang,Cansu,745000,China

出　　处：《Geoscience Frontiers》2017年第1期93-106,共14页地学前缘（英文版）

基　　金：supported by a grant from the Key Project of the National Science and Technology(2011ZX05009-02)

摘　　要：Diverse and abundant microfossils, such as palynomorphs, algae and Ostracoda, were collected from lower Cretaceous strata of Lishu depression, located in southeastern Songliao basin, and were identified and classified in order to provide relevant, detailed records for paleoclimate research. The early Creta- ceous vegetation and climate of southeastern Songliao basin have been inferred from the analysis of palynomorph genera, algae and Ostracoda of the LSI and SW110 wells. The lower Cretaceous strata include, in ascending stratigraphic order, the Shahezi, Yingcheng and Denglouku formations. Palyno- logical assemblages for each formation, based on biostratigraphic and statistical analyses, provide an assessment of their longitudinal variations. During deposition of the Shahezi Formation, the climate was mid-subtropical. Vegetation consisted of coniferous forest and herbage. During deposition of the Ying- cheng Formation, the climate was south Asian tropical. Vegetation consisted mainly of coniferous forest and herbal shrub. In addition, fresh and saline non-marine water dominated the lacustrine setting during deposition of these formations. Deposition of the Denglouku Formation, however, occurred under a hot and dry tropical climate. The vegetation was mostly coniferous forest and lake waters became saline. Palaeoclimate variation is correlated by the lake level change and the development of sedimentary facies. Palaeoclimate contribute to the formation of hydrocarbon source rocks and reservoir.Diverse and abundant microfossils, such as palynomorphs, algae and Ostracoda, were collected from lower Cretaceous strata of Lishu depression, located in southeastern Songliao basin, and were identified and classified in order to provide relevant, detailed records for paleoclimate research. The early Creta- ceous vegetation and climate of southeastern Songliao basin have been inferred from the analysis of palynomorph genera, algae and Ostracoda of the LSI and SW110 wells. The lower Cretaceous strata include, in ascending stratigraphic order, the Shahezi, Yingcheng and Denglouku formations. Palyno- logical assemblages for each formation, based on biostratigraphic and statistical analyses, provide an assessment of their longitudinal variations. During deposition of the Shahezi Formation, the climate was mid-subtropical. Vegetation consisted of coniferous forest and herbage. During deposition of the Ying- cheng Formation, the climate was south Asian tropical. Vegetation consisted mainly of coniferous forest and herbal shrub. In addition, fresh and saline non-marine water dominated the lacustrine setting during deposition of these formations. Deposition of the Denglouku Formation, however, occurred under a hot and dry tropical climate. The vegetation was mostly coniferous forest and lake waters became saline. Palaeoclimate variation is correlated by the lake level change and the development of sedimentary facies. Palaeoclimate contribute to the formation of hydrocarbon source rocks and reservoir.

关 键 词：Palynomorph Palaeoclimate Early Cretaceous Lishu depression Songliao Basin 

分 类 号：Q911[天文地球—古生物学与地层学] P532[生物学—古生物学] P534.53