Climate characteristics of the eastern Mongolian Plateau,China during the early Early Cretaceous(145-132 Ma):Palynological evidence from the Tongbomiao Formation in Well Hong-6,Hailar Basin  

作　　者：Yan Zhang Yun-fei Xue Chun-yang Bu Ti Li Xin Zhang Yu-dong Jin Yue-wu Sun 

机构地区：[1]College of Earth Sciences,Jilin University,Changchun 130061,China [2]Geological Laboratory,Exploration and Development Research Institute of Daqing Oilfield Company Ltd.,Daqing 163712,China [3]Research Center of Paleontology and Stratigraphy,Jilin University,Changchun 130026,China

出　　处：《China Geology》2022年第3期439-456,共18页中国地质（英文）

基　　金：financially supported by the National Natural Science Foundation of China (41972012 and 31270277).

摘　　要：This study identified two palynological assemblages,namely Bayanhuasporites-Cycadopites-Protoconiferus and Cicatricosisporites-Cedripites-Perinopollenites,in the Tongbomiao Formation in the Hongqi Sag in the Hailar Basin,Inner Mongolia,China for the first time.The former is distributed in the lower part of the Tongbomiao Formation and is characterized by abundant gymnosperm pollen and diverse fern spores.Among them,the gymnosperm pollen is dominated by Paleoconifer(4.98%-31.62%)and Cycadopite(8.55%-25.23%)pollen grains and also includes other pollen grains such as Classopollis,Parcisporites,Erlianpollis,Callialasporites,and Jiaohepollis.The fern spores in the former palynological assemblage contain Bayanhuasporite(0-8.96%),Granulatisporites(0.93%-6.97%),and some important Cretaceous genera,such as Cicatricosisporites,Concavissimisporites,Densoisporites,Hsuisporites,Foraminisporis,and Leptolepidites.The Cicatricosisporites-Cedripites-Perinopollenites palynological assemblage is distributed in the upper part of the Tongbomiao Formation.Gymnosperm(77.30%),Pinaceae(31.9%),and Paleoconiferus(19.02%)pollen predominate this palynological assemblage,and Quadraeculina,Erlianpollis,and Jiaohepollis pollen are also common in this assemblage.The fern spores in this palynological assemblage include abundant Cicatricosisporites(4.29%).Besides,Concavissimisporites,Aequitriradites,and Leptolepidites are also common in this palynological assemblage.No angiosperm pollen has been found in both palynological assemblages.The identification of both palynological assemblages provides important evidence for the biostratigraphic correlation between the Hailar Basin and its adjacent areas.It also enables the reconstructions of the Berriasian-Valanginian(Early Cretaceous)vegetation and the paleoclimate on the eastern Mongolian Plateau during 141-132 Ma.The vegetation reconstructed on the palynological data of the represented by Hailar Basin in eastern Mongolian Plateau(141.6-141.4 Ma),form conifer forest or conifer broad-leaved mixed fores

关 键 词：Tongbomiao Formation Palynological Assemblages GYMNOSPERM Berriasian-Valanginian PALAEOVEGETATION Palaeoclimate Hailar Basin Mongolian Plateau China 

分 类 号：P532[天文地球—古生物学与地层学] Q913.84[天文地球—地质学]