小寺沟铜钼矿成岩-成矿系统浅析

河北小寺沟斑岩铜钼矿是华北地区一个大型铜钼矿床。本文通过分析小寺沟岩体地质特征，认为本岩体为脉动式侵入的浅成复式岩体，呈岩枝状产出，且岩石具典型的斑状结构；通过剖析岩体主量元素与稀土元素特征，认为属典型的Ⅰ型花岗岩；综合分异指数、Mg#指数和无铕异常等多方面特征，认为结晶分异作用在斑岩岩浆演化中不占主导地位，而岩浆来源于下地壳部分熔融与加入的玄武质岩浆。以上特征均与斑岩型铜钼矿床含矿岩体相当。最后，通过矿床硫同位素及硫化物稀土元素特征的研究，利用对比分析法，揭示研究大型斑岩型矿床的要素。

Primary Analysis of Magmatic Rocks and Ore - forming System of Xiaosigou Copper- molybdenum Porphyry deposit, North China

Xiaosigou copper - molybdenum deposit is a large - scale porphyry deposit in Hebei province, North China. Geological feature of the intrusion indicated that it＇s an apophysis - shape pulsating intruded of hypabyssal facies, with typical porphyritic texture. Chemical analysis results of major and rare earth elements suggest that those magmatic rocks are belongs to I - type granite, while integrated differentiation index and mafic index and Eu anomaly comes the results that the granitic magma is from partial melting of lower crust which maybe contaminated by basaltic magma, and not come through crystallization differentiation in the ascending process. All the characteristics of the magmatic rocks from Xiaosigou deposit is similar to typical large porphyry deposit. The sulfur isotope and rare earth elements contents of sulfides of Xiaosigou deposit are analyzed to reveal the essential characters of large scale porphyry deposit.