华北板块北缘中二叠统于家北沟组植物化石及其大地构造意义  

Fossil Plants from the Guadalupian Yujiabeigou Formation in the North Margin of North China Plate and Their Tectonic Implications

作　　者：孙跃武[1] 丁海生[1] 刘欢 张德军[3] 公繁浩[3] 郑月娟[3] 

机构地区：[1]吉林大学古生物学与地层学研究中心,长春130026 [2]中国地质调查局天津地质调查中心,天津300170 [3]中国地质调查局沈阳地质调查中心,沈阳110034

出　　处：《吉林大学学报（地球科学版）》2016年第5期1268-1283,共16页Journal of Jilin University：Earth Science Edition

基　　金：中国地质调查局项目(1212011121086;121201120966)~~

摘　　要：通过对内蒙古赤峰市广兴源乡于家北沟组模式剖面植物化石和安山质晶屑岩屑凝灰岩锆石UPb同位素年代学的研究,结合动物化石的分析,确认于家北沟组地质时代为中二叠世。于家北沟组植物化石以Gigantonoclea hallei Asama、Fascipteris sinensis Stockm.et Math.、Pecopteris taiyuanensis Halle、Pterophyllum daihoense Kaw.等众多华夏植物群典型分子为特征,属于典型的华夏植物群。目前,在中二叠世植物群中,从未发现有华夏和安加拉两大植物群的混生现象,这一事实进一步表明,中二叠世横亘于华北板块和佳蒙地块之间的古亚洲洋尚未闭合,在植物地理分布上起着重要的阻隔作用。Based on the studies of fossil plants and animals （including fusulinids, brachiopods and bivalves）, and the U-Pb isotopic dating of zircons from the andesitic crystal-lithic tuff in the type section of the Yujiabeigou Formation, the geological age of the formation is confirmed to be Guadalupian （Middle Permian） in the Guangxingyuan Town, Chifeng City, Inner Mongolia, China. The fossil plants in the type section of the Yujiabeigou Formation are characterized by the typical elements of the Cathaysia floras, such as Gigantonoclea hallei Asama, Fascipteris sinensis Stockm. et Math., Pecopteris taiyuanensis Halle, Pterophyllum daihoense Kaw. Therefore, the plant fossils in the Yujiabeigou Formation belong to the typical Cathaysia flora, phytogeographically. Among the Guadalupian floras in China, there isn＇t any mixed flora of Cathaysia and Angara found till now. This indicate further that the Paleo-Asian Ocean lain between the North China plate and the Jiamusi-Mongolia block was not closed during the Middle Permian, and being an important barrier in the Guadalupian global floristic geographical distribution.

关 键 词：中二叠世 华夏植物群 西拉木伦河-延吉缝合带 华北板块 佳蒙地块 古亚洲洋 

分 类 号：Q914.646[天文地球—古生物学与地层学]