内蒙古渣尔泰山群地层地球化学特征及含矿性

Geochemical Characteristics and Ore-bearing Potential in Zha'ertaishan Group,Inner Mongolia

在充分研究已有资料的基础上,通过野外实地调研,以内蒙古中西部渣尔泰山地区为主要研究对象,对渣尔泰山群地层进行了划分,并探讨了该地层地球化学特征,最后就该地层含矿性进行了评价。结果表明:中元古界渣尔泰山群为一套浅变质岩系,属裂谷系中的碎屑岩、炭质页岩、粉砂岩和碳酸盐岩建造,自下而上分为书记沟组、增隆昌组、阿古鲁沟组和刘鸿湾组,主要含矿层为阿古鲁沟组;渣尔泰山群沉积环境呈现由陆相→正常海相→半封闭海相或次深海相→滨海相的正常海进海退序列变化特征;渣尔泰山群地层在纵向上自下而上表现为亲碎屑元素组合→亲碳酸盐元素组合→亲铁、亲硫元素组合→亲碳酸盐、亲碎屑岩的混合组合;岩石组分与成矿元素有显著相关性,泥质、钙镁质岩富含铅、锌及硫铁,高硅质岩石富含铜,有机碳含量往往与矿层的规模、质量成正消长关系;不同的构造演化阶段和沉积环境致使元素分布不均匀,体现在含矿性在东西走向的规律性变化,即东部甲生盘—山片沟矿床贫铜富锌,少伴生元素,而西部狼山地区铜、铅、锌共生,贫铅锌富铜,伴生元素较多。

Based on the current data and field research,Zha＇ertaishan in the midwest of Inner Mongolia was taken as research object;Zha＇ertaishan Group was divided;the geochemical characteristics were discussed;and the ore-bearing potential was evaluated.The result showed that Mesoproterozoic Zha＇ertaishan Group,as a set of epimetamorphic rock series,consisted of clasolite,macker,siltite and carbonatite in a rift system,and was divided into Shujigou,Zenglongchang,Agulugou and Liuhongwan Formations from bottom to top;depositional environment of Zha＇ertaishan Group showed the characteristic of normal transgression and regression sequence ＂continental facies→normal marine facies→semi-enclosed sea facies or bathyal facies→littoral facies＂;Zha＇ertaishan Group showed the element combinations ＂pro-scrap→pro-carbonate→siderophile and sulphophile→pro-scrap and pro-carbonate mixed＂ from bottom to top in the longitudinal;the correlation of rock constituents and metallogenic element was significant;argillaceous,calcareous and mafic rocks were rich in Pb,Zn and S-Fe;siliceous rock was rich in Cu,and the relationship between the content of organic carbon and the scale and quality of mineral deposit was positive eat and flow;the different stages of tectonic and the evolution of sedimentary environment caused the uneven distribution of elements,and it showed the change of ore-bearing potential from east to west,and particularly,Jiashengpan-Shanpiangou zinc poly-metallic deposit was poor in Cu,rich in Zn and a little accompaniment elements in the eastern part,several deposits in Langshan Area showed symbiotic Cu,Pb and Zn,rich in Cu,poor in Pb and Zn and many accompaniment elements in the western part.