秦岭凤镇小区中上泥盆统木桐沟金属矿床成因

发布时间：2018-03-01 09:56

  本文关键词： 铅锌矿 木桐沟 矿物成分 地球化学特征 矿床类型　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：木桐沟铅锌矿床,位于东秦岭海西~印支褶皱带北缘,凤太矿田水柏沟~谭家庄复背斜西部南缘,是秦岭地区典型的中型铅锌矿床。在大地构造位置上处于秦岭地槽系北缘凤县~镇安小区冒地槽中段。本文通过对木桐沟铅锌矿的矿床地质、薄片鉴定、主微量元素、稳定同位素地球化学特征进行研究,取得以下认识:1.木桐沟铅锌矿主矿体由于受到褶皱构造和地层层位的控制,Ⅰ号矿体呈现鞍部厚大,翼部薄的特征,Ⅱ号矿体呈单斜板状或层状,其水平切面呈豆荚状,赋矿于古道岭组和星红铺组。2.对矿床地质特征进行研究,矿体呈鞍状、似层状、透镜状产出;物质组成:矿石矿物成分为闪锌矿、方铅矿、黄铁矿等,脉石矿物为石英、白云石、方解石等;矿石具条纹状、层纹状、浸染状、网脉状及块状构造;交代、草莓、环状、骸晶、溶蚀、共边等结构;矿床围岩蚀变,主要限于矿化带内,有硅化、铁碳酸盐化、黄铁矿化等,硅化和铁碳酸盐化与成矿关系密切,为标准型的近矿围岩蚀变等。3.对铅同位素进行铅构造模式投图,通过其投点图分析可知,木桐沟的铅主要来自于上地壳,并混入了少量的地幔物质。稀土元素具有较低的稀土元素总量,稀土同时表现出轻稀土富集,∑LREE与∑HREE比值、不明显的Ce负异常和弱的负铕异常证明其为还原环境。4.木桐沟铅锌矿床S同位素组成,δ34S值的变化范围为于4.1‰~12.8‰之间,平均7.47‰,极差为8.7‰,反映了本区有深源硫或地幔硫特征,没有生物有机硫的参与,同时硫化物中硫来源很可能为当时海水硫酸盐中的还原硫和深部硫的混合物。5.综合对比木桐沟铅锌矿床与MVT和SEDEX矿床的特征,认为其矿床类型为喷流—沉积型。
[Abstract]:The Mutonggou lead-zinc deposit is located in the northern margin of the Hercynian-Indosinian fold belt in the East Qinling Mountains, and in the western southern margin of the Shuibaigou-Tanjiazhuang anticline in the Fengtai Orefield. It is a typical middle-sized lead-zinc deposit in Qinling area. It is located in the middle section of Fengxian ~ Zhenan district in the northern margin of Qinling geosyncline system. The deposit geology, thin section identification and main trace elements of Mutonggou Pb-Zn deposit are studied in this paper. The stable isotopic geochemical characteristics have been studied and the following understandings have been obtained: 1.The main orebody of Mutonggou lead-zinc ore body is controlled by fold structure and stratigraphic position, and the No. 1 orebody is characterized by large saddle thickness and thin wing. The No. 2 orebody is monocline or layered, and its horizontal section is pod-like. The orebody is located in Gudaoling formation and Xinghongpu formation. 2. The geological characteristics of the deposit are studied. The orebody is saddle-shaped, bedded and lenticular. Material composition: mineral composition of ore is sphalerite, galena, pyrite, etc., gangue mineral is quartz, dolomite, calcite, etc.; ore is striped, laminated, disseminated, reticulate and massive; metasomatism, strawberry, annular, etc. The alteration of the surrounding rock of the deposit is mainly confined to the mineralized zone, such as silicification, iron carbonate, pyrite, etc., and the silicification and iron carbonization are closely related to the mineralization. For the standard type near ore wall rock alteration, etc. 3. The lead isotopic pattern of lead structure is cast. Through the analysis of the drop point diagram, it can be seen that the lead of Mutong gully mainly comes from the upper crust. And mixed with a small amount of mantle material, the rare earth elements have a relatively low amount of rare earth elements, and the rare earth elements are enriched with light rare earth elements, and the ratios of 鈭，

本文编号：1551439