沙坪沟钼矿床岩浆岩中镁铁云母地球化学特征及其成岩成矿意义

发布时间：2018-09-04 13:48

【摘要】：沙坪沟钼矿是东秦岭-大别地区近年来发现的特大型斑岩型钼矿床,为从矿物学角度研究其成岩成矿规律,采用电子探针方法分析了矿区复式岩体中的镁铁云母成分,并与中国其他地区的含矿中酸性岩体中的镁铁云母进行了对比。结果表明,沙坪沟钼矿区岩体中有3种镁铁(黑)云母:原生富镁黑云母和铁金云母、金云母,其AlⅥ为0.05~0.14,Mg/(Mg+Fe)为0.58~0.84,Mg O为15.95%~23.63%,MF[Mg/(Mg+Fe~(2+)+Mn)]为0.62~0.91,指示沙坪沟岩体具有造山带钙碱性岩套Ⅰ型花岗岩特征,铁金云母和金云母具有幔源特征,富镁黑云母具有壳幔混源特征。金云母和铁金云母仅见于含矿岩体花岗斑岩和石英正长岩中,暗示成流体主要来自幔源。沙坪沟含矿岩体比非含矿岩体的镁铁云母更富镁质、贫铁质,与中国其他地区的比较表明,沙坪沟岩体镁铁云母具有较高的镁质和较低的铁质,说明镁铁云母的地球化学特征对东秦岭乃至中国的斑岩型钼矿成矿具有一定的指示意义并可作为找矿标志。
[Abstract]:Shapinggou molybdenum deposit is a very large porphyry type molybdenum deposit discovered in East Qinling and Dabie area in recent years. In order to study its diagenetic and metallogenic regularity from a mineralogical point of view, the composition of magnesia-ferromanite in the complex rock mass of ore area is analyzed by electron probe method. The results are compared with that of magnesium-ferromanite in intermediate-acid ore-bearing rock bodies in other regions of China. The results show that there are three kinds of magnesia-ferric (biotite) mica: primary magnesium-rich biotite and ferric mica in the Shapinggou molybdenum ore area. Its Al 鈪，

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