黑龙江鹿鸣钼矿床成矿岩体岩石地球化学特征

Geochemical Characteristics of Mineralization Rock from the Luming Molybdenum Deposit in Heilongjiang Province

鹿鸣钼矿床产于燕山早期二长花岗岩-花岗斑岩岩体中,对其岩石学和地球化学特征进行分析.结果表明：SiO2质量分数在63.84%-71.32%之间,全碱质量分数为6.9%-8.4%,w（K2O）/w（Na2O）平均为1.37.岩体大部分属于偏铝-过铝质高钾钙碱性花岗岩.稀土元素总量值高,轻稀土富集,稀土分配模式为右倾曲线,同时Eu出现弱到中等程度的亏损.研究认为与成矿有关的二长花岗岩-花岗斑岩的岩浆属壳源岩浆演化形成的A2型花岗岩岩石组合,其形成背景应属于陆-陆碰撞之后的伸展体系.

The Luming molybdenum deposit occurs in early Yanshanian pluton consisting of adamellite and granite porphyry.The data of petrography and geochemistry show that the SiO2 content varies from 63.84% to 71.32%,total alkali content varies from 6.9% to 8.4%,and w（K2O） /w（Na2O） has an average value of 1.37.Most of the rocks belong to metaluminousperaluminous high potassium calc-allkaline granite.The rocks have high total REE content.LREE is relatively enriched.The chondrite-nomalized REE patterns show that the curves of REE are right dip types with slightly-moderate negative Eu anomalies.The adamellite and granite porphyry magma which relates to mineralization belong to A2 type granite formed by the crust material source magma evolution.It is inferred that the pluton was formed by the conversion from a postcollisional environment to an extensional environment.