Late Cretaceous Palynological Assemblage and Its Palaeoclimate Record from Yaojia Formation in Qianjiadian Depression, Kailu Basin
Xu Zenglian
Wei Jialin
Zeng Hui
Li Hongliang
Li Jianguo
Zhu Qiang
Zhang Bo
Cao Minqiang
Abstract：The study on the palynology from the Yaojia Formation can provide palynology data and lay the basis on Late Cretaceous stratigraphic classification and correlation in the northeastern area of Kailu basin.Abundant sporopollen fossils of 88 species from 73 genera were recognized from the interval of 315 to 447 m of well QIV-48-61 in the Qianjiadian depression,Kailu basin in this study.Three sporopollen assemblages are established,namely the Schizaeoisporites-Cyathidites-Tricolpopollenites assemblage,the Schizaeoisporites-Classopollis-Taxodiaceaepollenites assemblage and the Schizaeoisporites-Exesipollenties-Tricolpopollenites assemblage.According to the geological range of some important elements and the correlation with relevant assemblages of other areas,the geological era of these sporopollen assemblages is assigned to the Late Cretaceous,which is equal to the Late Coniacian-Early Santonian Stage.Based on ecological characteristics,climate and humidity condition for the vegetation type of the sporopollen from the Qianjiadian area,3 phases of paleovegetation and paleoclimate are reconstructed as follows.(1) It was humid/semi-humid tropic-subtropic climate during the interval of 405.9 to 413.2 m,presenting a vegetation landscape of coniferous forest and grass.(2)The vegetation type during the interval of 389.7 to 405.9 m was characterized by the dominance of coniferous forest,and the climate turned hot and dry,marked by the increase in the drought-tolerant taxa,corresponding to semi-arid tropic-subtropic climate.(3) Similar to the first phase,the vegetation type during the interval of 336.0 to 389.7 m was also coniferous forest including grass,which belonged to semi-humid and semi-arid tropic-subtropic climate.
Keywords：palynological assemblagepalaeoclimateYaojia FormationLate CretaceousQianjiadian depressionKailu basinpaleontology
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：11( 1725-1735 )