论浙东南磨石山群祝村组的解体  

On disintegration of Zhucun formation, Moshishan group in southeast Zhejiang province

作　　者：俞云文 胡开明 

机构地区：[1]浙江省地质调查院,浙江萧山311203

出　　处：《火山地质与矿产》2001年第3期170-176,共7页Volcanology & Mineral Resources

摘　　要：对浙东南磨石山群祝村组层型———丽水祝村剖面及其附近进一步地质调查时发现祝村组“下伏”的九里坪组为一个英安玢岩侵出体。祝村组建组的基础不存在。祝村组下部英安质熔结凝灰岩和上部流纹岩Nd同位素测定结果 :εNd(t)值和T2DM值分别为 - 9.6、- 7.2和1.70Ga、1.5 1Ga ,表明它们物质来源不同 ,属于不同火山旋回的产物。根据地层层序、岩石组合及与区域磨石山群地层对比 ,祝村组应解体为西山头组、茶湾组和九里坪组。The Jiuliping formation underlyed Zhucun formation is a dacite porphyrite intrusive body through the further investigation on Zhucun formation section , Lishui-the typical section of Zhucun formation, Mashishan group in Southeast Zhejiang province. The basement of establishment of Zhucun formation is lost . The Nd isotopic compositions of dacite welded tuff from low part of Zhucun formation are dif ferent from those of rhyolite of upper part , in which the εNd(t) and T 2DM are respectively -9.6, -7.2 and 1.70 Ga showing different origins and belonging to different valcanic cycle products. On the basis of stratigraphy sequence, rock association and correlation with the regional Moshishan group , the Zhucun formation ought to be disintegrated to Xishantou formation, Chawan formation and Jiuliping formation but the Zhucun formation can not be used .

关 键 词：岩石地层 磨石山群 祝村组 浙江 钕同位素 早白垩世 地层层序 岩石组合 火山旋回 

分 类 号：P534.53[天文地球—古生物学与地层学]