长江三峡地区乐平统与阳新统的分界  

BOUNDARY BETWEEN THE YANGSINGIAN AND LOPINGIAN SERIES IN THE YANGTZE GORGES AREA

作　　者：冯少南[1] 李旭兵[1] 

机构地区：[1]中国地质调查局地层古生物研究中心,湖北宜昌443003

出　　处：《华南地质与矿产》2002年第2期66-69,共4页Geology and Mineral Resources of South China

基　　金：中国地质调查局地质大调查项目 ( 2 0 0 11390 0 0 72 )

摘　　要：长江三峡地区阳新世—乐平世沉积可以分为南型和北型。北型该期主要为浅海碳酸盐岩台地沉积 ,阳新世晚期的王坡组为粘土岩夹灰岩或硅质灰岩扁豆体 ,产Yabenia带及有孔虫 ,其上覆的吴家坪组产Clarkinaleveni,C liangshanensis等 ,阳新统与乐平统的分界置于Yabenia带的顶和含C leveni(可能有C dukouensis带 )的吴家坪组底。南型从阳新世晚期至乐平世主要为硅质岩、硅质灰岩 ,夹含煤碎屑岩 ,在吴家坪组的底部含牙形石C dukouensis带和C leveni带 ,该区阳新统与乐平统的分界置于C dukouens带泥质灰岩 (腕足类富集层 )的底 ,下伏的煤系地层时代为阳新世晚期。The Yangsingian and Lopingian deposits in the Yangtze Gorges Area show different sedimentary characteristics and fossil assemblage in different areas. In the northern part, the Wangpo Formation of Yangsingian Series is composed of clay with limestone and siliceous lens containing Yabenia Zone and foraminiferas, Its upper Wujiaping Formation developed abundant fossils at the base, such as Clarkina leveni and C.lingshanensis , and the boundary between Yangsingian Series and Lopingian Series is just above the Yabenia Zone and below the Clarkina leveni Zone. In the southern part, the Yangsingian and Lopingian deposits consist mainly of siliceous limestone, silicalites and siliceous coal-bearing shale.There exist abundant fossils in the mud-limestone lenses and iron spar-limestone in the bottom of the Wujiaping Formation, such as Clarkina niuzhuangensis, C.Leveni, C.dukouensis and C.lingshanensis , and the boundary between Yangsingian and Lopingian Series is below the Clarkina dukouensis .

关 键 词：阳新统 长江三峡地区 二叠系 地质时代 灰岩 粘土岩 

分 类 号：P534.46[天文地球—古生物学与地层学]