内蒙古贺根山蛇绿岩的铬铁矿中发现金刚石等深部地幔矿物  

The discovery of diamonds and deep mantle minerals in chromitites of Hegenshan ophiolite, Inner Mongolia

作　　者：黄竺[1,2] 杨经绥[1] 朱永旺 熊发挥[1] 刘钊[4] 张仲明[1] 

机构地区：[1]大陆构造与动力学国家重点实验室地幔研究中心,中国地质科学院地质研究所,北京100037 [2]中国地质大学(北京),北京100083 [3]内蒙古自治区第九地质矿产勘查开发院,内蒙古锡林浩特026000 [4]中国地质科学院矿产资源研究所,北京100037

出　　处：《中国地质》2015年第5期1493-1514,共22页Geology in China

基　　金：中国地质调查局(12120114061801,12120114061501);国家自然科学基金(40930313)联合资助

摘　　要：前人报道在西藏中生代和俄罗斯极地乌拉尔早古生代蛇绿岩地幔橄榄岩铬铁矿中发现了金刚石等深部地幔矿物,认为需重新考虑铬铁矿浅部成因的传统认识。为了查明不同造山带蛇绿岩的铬铁矿中金刚石等深部矿物的分布规律和豆荚状铬铁矿的成因,笔者开展了内蒙古贺根山晚古生代蛇绿岩中的铬铁矿床的人工重砂矿物学研究,本研究获得约2000 kg的内蒙古贺根山蛇绿岩铬铁矿石样品,对所采样品开展人工重砂选矿,表明该铬铁矿矿石样品中至少有金刚石、碳硅石及其他自然元素类、金属互化物类、氧化物类、硫化物类、硅酸盐类等30余种矿物。内蒙—大兴安岭造山带晚古生代的内蒙古贺根山蛇绿岩带铬铁矿石中,发现金刚石等深部地幔矿物表明,贺根山铬铁矿可能为深部成因。Diamond and other deep mantle minerals, previously found in the Mesozonic Tibet and the early Paleozoic Polar Ural,Russia, are now found in ophiolite mantle peridotite chromite. Hence the traditional opinion holding shallow origin of ophiolite and chromite should be reconsidered. In order to find out the distribution of diamond and other deep mantle minerals in different orogenic ophiolite chromites and to investigate the formation processes of the Hegenshan podiform chromitites, the authors carried out mineralogical study of chromitites in the Hegenshan ophiolite, Inner Mongolia. Approximately 2000 kg of mainly disseminated chromitite ore were collected from Hegenshan No. 3756 orebody. By mineral separation, preliminary studies identified more than 30 mineral species in addition to diamonds and moissanite. The other minerals include minerals of oxides, sulfides, silicates, and other compounds. This study demonstrates that the formation and tectonic setting of Hegenshan ophiolite and the chromitites deserve reevaluation.

关 键 词：金刚石 深部地幔矿物 铬铁矿 贺根山 内蒙古 

分 类 号：P578.16[天文地球—矿物学] P618.313.3[天文地球—地质学]