泥河湾盆地晚新生代微体古生物地层及环境演化的探讨  

Late Cenozoic Micropalaeontology in the Nihewan Basin and Its Implications for Environmental Evolution

作　　者：庞其清[1] 翟大有[2] 赵筑簾 张正平[3] 

机构地区：[1]石家庄经济学院,河北石家庄050031 [2]中国科学院地质与地球物理研究所,北京100029 [3]河北省区域地质矿产调查研究所,河北廊坊065000

出　　处：《地质学报》2015年第5期817-842,共26页Acta Geologica Sinica

基　　金：河北省国家级自然保护区能力建设项目;河北省东方人类探源工程-泥河湾人类起源;地质及环境背景研究项目的资助成果

摘　　要：通过对泥河湾盆地43条剖面和6个钻孔晚新生代地层和微体古生物（介形类和有孔虫）的调查研究,发现非常丰富的介形类,计26属70余种,有孔虫4属4种,其中介形类自下而上可明显地划分为5个组合带：（1）Potamocypris plana-Candoniella-Ilyocypris组合带;（2）Leucocythere-Ilyocypris-Candoniella组合带;（3）Leucocythere-Cytherissa-Limnocythere组合带;（4）Ilyocypris-Limnocythere flexa-Limnocythere dubiosa组合带;（5）Limnocythere dubiosa-Limnocythere sancti-Patricii-Ilyocypris组合带。按以上5个介形类组合带的分布,第1组合带及所含地层红崖村组和石匣组的时代为上新世;第2~4组合带及所含地层泥河湾组的时代为早更新世;第5组合带为中-晚更新世,分布于虎头梁组和许家窑组,虎头梁组置中更新世为宜,许家窑组为晚更新世。根据5个介形类组合带和有孔虫的分布及介形类的始现、繁盛、兴衰的演替特征,对泥河湾古湖和盆地的形成经历了上新世的起始,早更新世早期的扩展,中、晚期稳定、发展、湖面最大,中更新世向西部退缩和晚更新世消亡、桑干河水系形成五个发展阶段的演化进行了探讨。Late Cenozoic micropalaeontological fossils（including ostracoda and foraminifera）and biostratigraphy from forty-one sections and 6drilling cores in the Nihewan basin were investigated in this study.Abundant fossils found contain 26 genus 70species of ostracoda and 4genus 4species of foraminifera.The ostracoda can be subdivided 5assemblage zones（from old to new as follows）：1.The first assemblage zone：Potamocyprisplana Candoniella Ilyocyprisassemblage zone.This assemblage zone are distributed in the Shixia Formation and a few fossils are found in the Upper Hongyacun Formation and mainly contain Potamocypris plana Schneider,P.cf.horrida Schneider,Candoniella mirabilis Schneider,C.albicans（Brady）and a fewIlyocypris bradyi Sars,I.gibba（Ramdohr）,I.dunschanensis Mandelstam,I.cornae Mandelstam,Candona lantianensis Lee,Candoniella suzini Schneider,Eucypris cf.decurta Schneider etc..2.The second zone：Leucocythere-Ilyocypris-Candoniella assemblage zone.The assemblage zone are distributed the Lower Member of the Nihewan Formation and the genus Leucocythere appearance is mainly characteristic.The fossils of the assemblage zone consist of 17 genus 40species and mainly contain：Leucocythere mirabilis Kaufmann,L.exilitropis Huang,L.buranensis Huang,Ilyocypris spp.,Candoniella spp.,Candona spp.,Heterocypris spp.,Eucypris spp.,Cyclocypris sp.,Cypridopsis sp.,Zonocyprissp.,Darwinula stevensoni（Brady et Robertson）,Tanella opima Chen ect..3.The third zone：Leucocythere-Cytheressa-Limnocythere assemblage zone.This assemblage zone are distributed in the Middle Member of the Nihewan Formation.The Limnocythere flexa Negadaev appearance is mainly characteristic and mainly contain 16 genus 40spuies：Leucocythere mirabilis Kaufmann,L.burangensis Huang,Cytherissa lacustris（Sars）,Ilyocyprisspp.,Candonaspp.,Candoniellaspp.,Cyclocypris sp.,Eucypris spp.,Heterocypris sp.,Cyprideis sp.,Darwinula stevensoni（Brady et Robertson）etc..4.The forth zone：Ilyocypris-Limnocythere flexa-Limnocythere dubiosa assemblage

关 键 词：介形类 有孔虫 生物地层 晚新生代 环境演化 泥河湾盆地 

分 类 号：Q913[天文地球—古生物学与地层学] P534.6[生物学—古生物学]