浙江江山丁家山组层状硅质岩阴极发光特征及成因探讨  

Origin of Bedded Chert from Dingjiashan Formation in Jiangshan Region,Zhejiang Province:evidence from cathodeluminescence

作　　者：曹秋香[1,2] 郭福生[1,2] 刘向铜[1] 杜杨松[2] 严兆彬[1,2] 张松[1] 孙文洁 

机构地区：[1]东华理工大学地球科学与测绘工程学院,江西抚州344000 [2]中国地质大学地质过程与矿产资源国家重点实验室,武汉430074 [3]山东省煤田地质局第三勘探队,山东泰安271000

出　　处：《沉积学报》2008年第5期797-803,共7页Acta Sedimentologica Sinica

基　　金：国家自然科学基金重点项目(批准号:40334038);国家自然科学基金(批准号:40572077)的联合资助

摘　　要：浙江江山中二叠世丁家山组,主要由黑色薄层状硅质岩、硅质粉砂岩、粉砂岩夹微晶灰岩组成。黑色薄层状硅质岩以高SiO2、富Al2O3、富Fe2O3、低TiO2和低MnO为特征,REE含量低,具弱Ce亏损、Tm正异常。硅质岩的阴极发光特征和岩石学特征表明,岩石属于交代成因,原岩可能为含生物碎屑灰岩,岩石硅化前曾发生过白云化作用。地球化学研究表明,硅质来源于正常地下水及陆源硅胶,无热水或火山硅质来源的迹象。The Dingjiashan Formation of the Middle black lamellar and bedded cherts, siliceous siltstone, Permian in Jiangshan, Zhejiang Province is composed of the and siltstone intercalated with micrite. The black bedded cherts are characterized by high SiO2, rich in Al2O3 and Fe2O3, low TiO2 and MnO, low REE values, Ce deficiency and positive anomaly Tm value. The characteristics of eathodelumineseence and lithology have proved that these siliceous rocks were originated by replacement of sedimentary carbonates, such as bioclastic limestone, dolomitization were took place before silification. The chemical analysis data demonstrate that siliceous matter came from the normal underwater and continental silica gel, not from hydrothermal or volcanic silicon.

关 键 词：硅质岩 沉积地球化学 阴极发光 中二叠世 

分 类 号：P588.24[天文地球—岩石学]