内蒙古千里山铁矿成矿地质特征及矿物学研究

Study on Oreforming Geological Characteristics and Mineralogy of Qianlishan Iron Deposit in Inner Mongolia

摘要:

本文研究了位于华北克拉通西部陆块早元古代孔兹岩带中千里山研究区的地质特征。千里山铁矿区位于内蒙古乌海市，其地质构造复杂。通过对该区域岩石的岩相学特征分析，发现透辉石云母方柱石片岩、角闪二长片麻岩和透辉石黑云母方柱石角闪石片岩等岩石类型。根据电子探针研究结果表明，千里山角闪石多为高级变质成因，反映了孔兹岩带的古老基底及丰富变质岩特征。黑云母属于幔源型，靠近壳幔混源，有利于Au、Mo、Cu、Fe矿化。辉石化学成分显示母岩浆为拉斑玄武质系列，具有高SiO2，低TiO2、Al2O3、Na2O的特点。此外，千里山地区中辉石和黑云母的结晶温度高，指示母岩浆的高温特性，高氧逸度黑云母可能预示良好的Fe、Cu、Au成矿潜力，本研究为矿产勘查提供了重要线索。

Abstract:

In this paper, geological characteristics of Qianlishan study area located within early Proterozoic Khondalite Belt in the western block of the North China Craton have been studied. Qianlishan iron deposit is located in Wuhai city in Inner Mongolia with complex geological structures. Through analyzing petrographic characteristics in this area, diopsidemicascapolite schist, hornblende Monzonite gneiss and diopsidebiotitescapolitehornblende schist have been identified. According to electron probe microanalysis (EPMA) results, it is indicated that Qianlishan hornblende is mostly of highgrade metamorphic origin. It has reflected the characteristics of ancient basement and abundant metamorphic rock. The biotite is mantlederived, and near the crust mantle mixed source. It is favorable for mineralization of Au, Mo, Cu, and Fe. The chemical composition of pyroxene shows that the parent magma belongs to the tholeiitic series, characterized by high SiO2, low TiO2, Al2O3 and Na2O. In addition, high crystallization temperatures of pyroxene and biotite in Qianli Mountain area indicate hightemperature characteristics of parent magma. High oxygen fugacity biotite may indicate good mineralization potential for Fe, Cu, and Au. This study provides important clues for mineral exploration.