内蒙古宝音图钼矿床花岗岩稀土元素地球化学特征及花岗岩成因

宝音图钼矿床是近几年在内蒙古西部地区发现的大型斑岩型钼矿床。重点研究该钼矿床成矿花岗岩稀土元素地球化学特征，探讨花岗岩成因。通过对稀土元素配分模式和特征值（∑REE-LREE/HREE、δEu-LREE/HREE相关性）的分析，对比幔源岩浆及南岭花岗岩稀土元素组成特点，结合岩石化学组成，推断宝音图成矿花岗岩属于陆壳熔融成因花岗岩。由斜长花岗岩→二长花岗岩→钾长花岗岩→细晶花岗岩，岩体成分逐渐变化。岩浆演化中有成分分异，有利于成矿，特别是晚期钾长花岗岩富集成矿元素和矿化剂元素。

REE Geochemical Characteristics and Genesis of Granites in Baoyintu Molybdenum Deposit,Inner Mongolia

The Baoyintu molybdenum deposit, located in western Inner Mongolia, is a large scale porphyry molybdenum deposit which is discovered in recent years. This paper focuses on discussing REE geochemistry of ore-forming granites and genesis of granites. Based on analyses of REE distribution patterns, characteristic value (including ∑REE-LREE/HREE and δEu-LREE/HREE) and petrochemical compositions, comparisons with REE compositions of mantle-derived magma and Nanling granites, authors deduce that genesis of ore-forming granites is related to melting of the continental crust.The compositions of granites vary in the sequence of plagiogranite→monzoniticgranite→K-feldspar granite→graniteaplite. The chemical variation during the magmatic evolution process is in favour of mineralization,especially the late-stage K-feldspar granites.