冀北滦平盆地大北沟组—大店子组介形类生物地层和侏罗系—白垩系界线  

Ostracod biostratigraphy of the Dabeigou and Dadianzi formations and Jurassic-Cretaceous boundary in the Luanping basin, northern Hebei, China. Geological Bulletin of China,

作　　者：庞其清[1] 田树刚[2] 李佩贤[2] 牛绍武[3] 柳永清[2] 

机构地区：[1]石家庄经济学院,河北石家庄050031 [2]中国地质科学院地质研究所,北京100037 [3]中国地质调查局天津地质矿产研究所,天津300170

出　　处：《地质通报》2006年第3期348-356,共9页Geological Bulletin of China

基　　金：国家自然科学基金项目<侏罗系-白垩系界线过渡期大北沟阶至义县阶连续剖面及化石分带研究>(№.40472019)全国地层委员会项目<中国主要断代地层建阶研究>联合资助。

摘　　要：冀北滦平盆地火斗山乡张家沟大北沟组—大店子组剖面连续、出露好、沉积序列全、化石十分丰富。介形类的研究可划分为1个延限带、4个组合带和7个亚带。其中第Ⅰ(Luanpingella-Torinina-Eoparacypris)组合带及所包含的1、2(Luanpingella Postacuta和Torinina obesa)亚带,分布于大北沟组,显示了晚侏罗世晚期的特征。第Ⅱ—Ⅳ(Yanshanina-Cypridea-Rhinocypris, Cypridea-Yanshanina-Timiriasevia和Cypridea sulcata-C．shanyingensis)组合带及所包含的3～7(Cypridea stenolonga,C．xitaiyangpoensis,C．luanpingensis,C．sulcata和C．shanyingensis)亚带分布在大店子组,Cypridea开始并相继大量出现和繁盛,明显地具有早白垩世早期的特征。故侏罗系—白垩系的界线应置于第Ⅰ组合带与第Ⅱ组合带,即第2亚带与第3亚带之间。The section of the Dabeigou and Dadianzi formations at Zhangjiagou, Huodoushan Township, Luanping County, northern Hebei, is a wen-exposed, consecutive section with a complete sedimentary sequence and very rich fossils. Ostracod fossils may be grouped into one range zone, four assemblage zones and seven assemblage subzones. Assemblage zone Ⅰ （Luanpingella-Torinina-Eoporacypris） and its contained subzones 1 （Luanpingella postacuta） and 2 （Torinirta obesa） distributed in the Dabeigou Formation show late Late Jurassic features; assemblage zones Ⅱ-Ⅳ （Yanshanina-Cypridea-Rhinocypris, Cypridea-Yanshanina-Timiriasevia and Cypridea sulcata-C, shanyingensis ） and its subzones 3-7 （ Cypridea stenolonga, C. xitaiyangpoensis, C. luanpingensis, C. sulcata and C. shanyingensis）, which are found in the Dadianzi Formation and in which Cypridea began to appear in large numbers and propagate, evidently show the early Early Cretaceous features. So the JurassicCretaceous boundary should be placed between assemblage zone Ⅰ and assemblage zone Ⅱ, i.e. between subzone 2 and subzone 3.

关 键 词：侏罗系—白垩系界线 介形类 生物地层 大北沟组 大店子组 冀北滦平盆地 

分 类 号：P534.52[天文地球—古生物学与地层学] P534.53[天文地球—地质学]