安徽罗河铁矿床绿泥石和绿帘石微量元素特征研究

发布时间：2018-05-16 23:34

本文选题：罗河铁矿床 + 绿泥石　；参考：《合肥工业大学》2017年硕士论文

【摘要】：罗河铁矿床位于长江中下游成矿带内庐枞矿集区的西北部,是成矿带内资源量最大的铁矿床,其发现于上世纪七十年代,前人研究成果认为其属于玢岩型铁矿床。2013年,罗河矿床的深部又发现了厚大铁矿体,也称之为小包庄铁矿床。这是近年来在长江中下游成矿带内找矿的重大突破之一,具有重要的理论研究意义和勘探应用价值。本文在前人对罗河铁矿床地质特征、矿化蚀变分带特征研究基础上,以矿床中广泛发育的特征蚀变矿物绿泥石和绿帘石为研究对象,系统的采集了矿床-545m中段不同位置和四个钻孔-870-1850m不同深度的绿泥石和绿帘石样品。在详细的镜下鉴定和电子探针分析工作的基础上,开展了系统的LA-ICP-MS矿物原位分析实验,查明绿泥石和绿帘石中微量元素特征,分析不同微量元素之间的相关关系,得出了以下认识。绿泥石和绿帘石微量元素特征表明:(1)罗河矿床-545m中段不同位置的绿泥石和钻孔不同深度的绿泥石,均具有Fe与Na、Si、K呈负相关,而与Mg呈正相关的特征;(2)-545m中段绿泥石中Fe、Ti、Na、Zn、Ca元素的含量远高于钻孔中的绿泥石,含量变化范围也更广,而Si、Mg、Mn、K、Li元素含量则无明显差别。同时在同一钻孔中,较深处绿泥石的Fe、Mn、Cr、As、Zr、Sb、Hf、Th、U等元素含量要低于较浅处的绿泥石,而Ni、B、Mg、Ti、Co、Ni等元素则相反;(3)罗河铁矿床的绿帘石中Y vs Cr,Sr vs Mn,Y vs V,Co vs Ni,Ti vs As,Ti vs V元素之间都有着良好的正相关性。此外,国外诸多学者总结了斑岩型矿床的找矿勘探模型,利用绿泥石和绿帘石的微量元素含量可以计算出与矿化中心和成矿岩体的距离,并取得了良好的效果。本次工作在此基础上,对罗河铁矿床中的绿泥石和绿帘石进行了同样的研究,对比斑岩型矿床中绿泥石和绿帘石微量元素确定成矿中心位置的方法,估算了罗河铁矿床的矿化中心和隐伏岩体的位置。数据结果表明通过玢岩矿床中绿泥石和绿帘石微量元素特征估算矿化中心也是可行的,而推算出的成矿岩体的位置也与当前地质事实较为符合,具有一定的可信度。
[Abstract]:The Luohe iron deposit, located in the northwest of the inner Lu-abong ore concentration area of the middle and lower reaches of the Yangtze River, is the most abundant iron ore deposit in the metallogenic belt. It was discovered in the 1970s, and the previous research results considered it to belong to the porphyrite iron ore deposit. A thick iron ore body was found in the deep part of Luohe deposit, also known as Xiaobuzhuang iron deposit. This is one of the major breakthroughs in prospecting in the metallogenic belt of the middle and lower reaches of the Yangtze River in recent years and has important theoretical research significance and exploration and application value. Based on the study of geological characteristics and mineralization alteration zoning characteristics of Luohe iron deposit, this paper takes the widely developed alteration minerals chlorite and verdite as the objects of study. The samples of chlorite and verdite from different positions and four boreholes of -870-1850m in the middle segment of -545m ore deposit were systematically collected. On the basis of detailed microscopic identification and electron probe analysis, systematic in situ LA-ICP-MS mineral analysis experiments were carried out to find out the characteristics of trace elements in chlorite and verdite, and to analyze the correlation between different trace elements. The following conclusions are drawn. The trace element characteristics of chlorite and verdite indicate that there is a negative correlation between Fe and Na Si Si K in different positions of chlorite and chlorite at different depths of borehole in the middle segment of the Luohe River deposit at 545m. However, the content of Fe ~ (2 +) Ti-Na ~ (2 +) Zn ~ (+) Ca in chlorite is much higher than that in borehole, and the range of variation is wider, but there is no significant difference in the content of Si-Mg ~ (2 +) mn ~ (+) K ~ (+) Li in the middle segment of chlorite with positive correlation with mg. At the same time, in the same drilling hole, the content of Fe, mn, Cr, Cr, SbHfU and Thu in the deeper chlorite is lower than that in the shallower chlorite. On the other hand, there is a good positive correlation between Y vs Cr-Sr vs Mn-Y vs V + Co vs Ni + Ti vs As-Ti vs V elements in the green curtain of the Luo River iron ore deposit. In addition, many foreign scholars have summarized the prospecting and exploration models of porphyry deposits. The distance from mineralization center and ore-forming rock can be calculated by using trace element content of chlorite and verdite, and good results have been obtained. On the basis of this work, the chlorite and verdite in Luohe iron deposit were studied in the same way, and the methods of determining the metallogenic center of chlorite and verdite in porphyry deposit were compared. The location of mineralization center and concealed rock mass of Luohe iron deposit is estimated. The data show that it is feasible to estimate the mineralization center by the trace element characteristics of chlorite and verdite in porphyrite deposit, and the calculated location of ore-forming rock body is consistent with the present geological facts and has certain credibility.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.31;P595

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