内蒙古阿巴嘎旗必鲁甘干钼矿区地质特征及矿床成因浅析

Analysis on Geological Characteristics and Origin of Bilugangan Molybdenum Deposit in Abagaqi in Inner Mongolia

按传统大地构造理论,内蒙古阿巴嘎旗必鲁甘干钼矿区大地构造位置位于天山-内蒙地槽褶皱系,内蒙华力西晚期褶皱带中部,三级构造单元阿巴嘎旗复向斜中段,查干敖包倒转背斜的核部,区域构造运动以华力西晚期和印支期构造运动为主,印支期侵入岩———花岗斑岩与成矿关系密切,地壳深处重溶的原始岩浆侵入于砂质板岩、杂砾岩等围岩中,将围岩蚀变成各类角岩,经过分异,成矿物质大量聚集,冷凝后为成矿母岩,而容矿构造为含矿热液的运移、充填交代、矿质沉淀提供了有利空间,且矿化范围严格受热液蚀变范围控制,热液的多次脉动,控制了多阶段的矿化,热液蚀变的叠加部位是矿化富集的有利地段,认为在花岗斑岩和围岩的内外接触带附近易形成斑岩型钼矿床。

According to traditional tectonic theory,tectonic position of Bilugangan molybdenum deposit in Abagaqiin Inner Mongoliain locates in Tianshan Inner Mongolia geosynclinal fold system,middle part of late Variscan fold belt,middle part of Abagaqi synclinorium which is the third tectonic unit,and core part of Chagan＇aobo overturned anticline.Regional tectonic movements are mainly composed of late Variscan and Indosinian tectonic movements.Triassic intrusive rocks granite porphyry is closely related with min-eralization.Original magma in the deep part of crust intruded in sandy slate and mixed conglomerate rocks, and country rocks have been eroded into all kinds of hornfels eclipse.After differentiation,ore forming materials have been concentrated largely and formed mineralization mother rock after condensation.Host structure will provide favorable space for migration,filling and replacement and mineral precipitation of ore bearing hydrothermal.Its mineralization range will be strictly controlled by hydrothermal alteration range.Multiple pulsation of hydrothermal has controlled multi stage mineralization of hydrothermal al-teration.Superimposed parts are favorable for mineralization and ore enrichment.It is regarded that in the inner and outer contact zone of granitic porphyry and its country rocks,porphyry molybdenum deposit can be formed easily.