内蒙古敖仑花钼铜矿床与半砬山钼矿床对比研究

发布时间：2018-06-25 17:51

本文选题：敖仑花钼铜矿 + 半砬山钼矿　；参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：内蒙古敖仑花钼铜矿和半砬山钼矿床位于华北克拉通北缘西拉木伦河成矿带的北侧,是典型的斑岩型钼矿床。本文以敖仑花钼铜矿和半砬山钼矿床为研究对象,根据矿区地质、矿体、岩石地球化学、年代学特征以及钼矿成因,对两矿床进行初步对比研究,分析总结两矿床的共性、差异性以及其中的原因及联系。地质特征、年代学对比研究表明,两矿区的地层、岩浆岩类型基本相同,岩浆活动的时间和类型基本相同,都是早白垩世中酸性岩浆的产物。矿体特征对比研究表明,矿体均呈似层状透镜体形态产出,主要受斑岩体控制。敖仑花矿床的矿石组分以钼铜为主、半砬山矿床矿石组分以钼为主,矿石组构有差异。矿床的围岩蚀变及分带不同,敖仑花钼铜矿床与成矿关系密切主要的是硅化和钾化;而半砬山钼矿床与成矿关系密切最主要的是黄铁绢英岩化。石英脉与钼成矿有着紧密联系,通过研究石英脉的分布、形态,可以预测钼矿化的趋势。两矿床赋矿斑岩体的岩石地球化学特征相似,斜长花岗斑岩和花岗闪长斑岩都属于准铝质高钾钙碱性I型花岗岩,具有埃达克岩特征。富集Rb、Ba、K、Th、U等大离子亲石元素和Zr、Hf等高场强元素,相对亏损Ta、Nb、Ti等高场强元素。稀土元素配分曲线均成右倾的轻稀土富集型曲线,负Eu异常不明显。流纹斑岩在敖仑花矿床中以脉岩体形式出现,属于过铝质高钾钙碱性A型花岗岩;而在半砬山钼矿床中主要为围岩,属于准铝质高钾钙碱性A型花岗岩。均具有低Sr,高Y、Yb的特征,微量元素含量差别较大。两矿床中成矿物质主要来自壳源,但有少部分幔源物质混入,形成于早白垩世由挤压向伸展过渡的构造环境下。半砬山钼矿床与敖仑花钼铜矿床成因具有相似性和内在联系。
[Abstract]:The Oolun molybdenum copper deposit and the half Lashan molybdenum deposit are typical porphyry molybdenum deposits located in the northern margin of the North China Craton on the northern side of the Xilamulunhe metallogenic belt. In this paper, based on the ore area geology, orebody, rock geochemistry, geochronology and origin of molybdenum ore deposit, this paper makes a preliminary comparative study on the two deposits, and analyzes and sums up the commonness of the two deposits, taking the Oolun molybdenum copper deposit and the Bilashan molybdenum deposit as the research objects. Difference and its causes and connections. A comparative study of geological characteristics and geochronology shows that the strata and magmatic types of the two mining areas are basically the same, and the time and type of magmatic activity are basically the same, which are all the products of early Cretaceous intermediate-acid magma. The comparative study of orebody features shows that the orebodies are lenticular and mainly controlled by porphyry. The ore composition of the Aolunhua deposit is mainly molybdenum and copper, and the ore composition of the hemilashan deposit is molybdenum, and the ore fabric is different. The wall rock alteration and zonation of the deposit are different. The Oolun molybdenum copper deposit is closely related to metallogeny mainly by silicification and kalitization, while the hemilashan molybdenum deposit has the most close relationship with metallogeny, which is mainly yellow sericite. Quartz vein is closely related to molybdenum mineralization, and the trend of molybdenum mineralization can be predicted by studying the distribution and morphology of quartz vein. The petrogeochemical characteristics of the ore-bearing porphyry bodies of the two deposits are similar. Both the plagioclase granitic porphyry and granodiorite are quasi-aluminous high-potassium calc-alkaline I-type granites with the characteristics of adakite. Large ion lithophile elements, such as RbBX, Bazao, Ki, Thu and ZrHf, are enriched, and the high field strength elements such as Ta-Nb-Ti are relatively depleted. The distribution curves of rare earth elements are all light rare earth enrichment curves with right inclination, but negative EU anomalies are not obvious. The fluvial porphyry appears in the form of vein rock in the Aolunhua deposit and belongs to the peraluminous high-potassium calc-alkaline A-type granite, while in the Banlashan molybdenum deposit it is mainly surrounding rock and belongs to the quasi-aluminous high-potassium calc-alkaline A-type granite. All of them have the characteristics of low Srand high YYb, and the content of trace elements varies greatly. The ore-forming materials in the two deposits mainly come from crust source, but a few mantle materials are mixed in, which formed in the tectonic environment of early Cretaceous transition from compressional to extensional. There is a similarity and intrinsic relation between the Boulashan molybdenum deposit and the Oolun molybdenum copper deposit.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.41;P618.65

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