蓟县中元古界下马岭组中菱铁矿的发现及其意义  

Discovery of Siderite Concretes in Mesoproterozoic Xiamaling Formation,Jixian Section

作　　者：朱祥坤[1] 张衎[1] 张飞飞[1] 高兆富[1] 董爱国[1] 包创[1] 郭跃玲[1] 闫斌[1] 刘辉[1] 

机构地区：[1]中国地质科学院地质研究所,国土资源部同位素地质重点实验室,大陆构造与动力学国家重点实验室,北京100037

出　　处：《地质论评》2013年第5期816-822,共7页Geological Review

基　　金：国土资源公益性行业科研专项经费项目(编号201011027);地质调查项目(编号1212011121069)的成果

摘　　要：蓟县剖面中元古界下马岭组地层下部黑色岩系中发现丰富的铁质结核,经X射线粉晶衍射、显微镜下观察、能谱分析等方法鉴定,确定铁质结核主要由菱铁矿构成。这些菱铁矿可能具有经济意义。另外,野外和室内研究表明,无论是铁质结核还是黑色岩系本身,都匮乏硫化物。这一发现说明中元古代下马岭期的燕辽海盆水体贫氧、富铁、贫硫,不是硫化的海洋。Abundant Fe-rich concretes have been discovered in the Jixian Section of the Mesoproterozoic Xiamaling Formation. The concretes are consisted mainly of siderite as determined by X-ray diffraction, optical microcopy examination and energy-dispersion spectrometry, The discovery of siderite concretes in the Xiamaling Formation is not only of potential economical significance, but implies that the seawater was reducing and not sulfidic during the Xiamaling Period.

关 键 词：菱铁矿 中元古界 蓟县剖面 下马岭组 

分 类 号：P618.31[天文地球—矿床学]