内蒙古乌拉特中旗大乌淀石墨矿成因特征分析

发布时间：2018-06-12 11:14

  本文选题：石墨矿 + 热接触变质　； 参考：《地学前缘》2017年05期

【摘要】：石墨的矿物学特征研究是揭示石墨矿化成因机制的重要途径。在对内蒙古新发现的大乌淀特大型晶质石墨矿进行成因分析时,通过电子显微镜、扫描电镜、拉曼光谱、X射线粉晶衍射及碳同位素等石墨矿物特征分析手段,证实其石墨矿物已具备完整晶型,晶体片径长度20~70μm,厚度30~50nm,石墨矿化度在75以上。另外,结合矿床地质及矿物组合等方面的证据,初步判定该石墨矿具有热接触变质成因特征。矿床形成于中温低压弱还原环境中,矿化变质温度为520~600℃。在早二叠世中酸性岩浆热液的烘烤作用下,中元古界白云鄂博群尖山组地层中的有机碳发生变质结晶形成石墨矿化,富铝质成分重结晶为红柱石。石墨矿化品质与距离岩体远近、热传导系统圈闭性、后期变质作用叠加及原岩碳质成分的结构含量等因素有关。
[Abstract]:The study of the mineralogical characteristics of graphite is an important way to reveal the genetic mechanism of graphite mineralization. During the genetic analysis of the newly discovered ultralarge crystalline graphite ore in Dawudan, Inner Mongolia, the characteristics of graphite minerals were analyzed by means of electron microscope, scanning electron microscope, Raman spectrum X-ray powder diffraction and carbon isotope, etc. It is proved that the graphite mineral has a complete crystal form, the diameter of the crystal is 2070 渭 m, the thickness is 30 ~ 50 nm, and the degree of graphite mineralization is more than 75. In addition, combined with the geological and mineral assemblage of the ore deposit, it is preliminarily determined that the graphite ore has the characteristics of thermal contact metamorphism. The deposit was formed in the medium temperature and low pressure weakly reduced environment, and the mineralization metamorphic temperature was 520 ~ 600 鈩，

本文编号：2009469