豫西青岗坪花岗岩体地球化学特征及地质意义

从青岗坪金矿床花岗岩体的地质特征、常量元素地球化学特征、稀土元素地球化学特征和微量元素地球化学特征入手，对青岗坪花岗岩体的岩浆来源、成岩环境和成岩机制进行了分析。研究结果表明：岩石碱总量为6.51%~8.67%，碱度率为1.99~3.57，里特曼组合指数为1.94~2.60，铝饱和指数平均值为0.97，属于钙碱性准铝质岩石；轻重稀土含量比值为5.74~11.75，岩浆在演化过程中经历了较大程度的结晶分异；δEu和δCe分别为0.63~1.05、0.79~0.85，具有弱的铕负异常和弱的铈负异常；岩体中大离子亲石元素Th、U及高场强元素Hf相对富集，而大离子亲石元素Ba及高场强元素Nb、Ti相对亏损；青岗坪花岗岩为I型花岗岩，岩浆来源为地壳中未经风化作用的火成岩再熔，形成于后碰撞造山环境。

Geochemical Characteristics and Geological Significance of the Qinggangping Granite in the Western Henan Province

The magma source，diagenetic environment and diagenetic mechanism of Qinggangping Granite were analyzed from aspects of the geological features，the petrography，the geochemistry characteristics of major elements，trace elements and rare earth elements.The results indicated that w(Na₂O)+w(K₂O)，AR，σ and average value of A/CNK varies from 6.51% to 8.67%，1.99 to 3.57，1.94 to 2.60 and 0.97，respectively，which means the granite belongs to calc-alkaline and metaluminous rocks.The magma experienced greater crystallization differentiation during the evolution period and the ratio of LREE and HREE is between 5.74 and 11.75.δEu and δCe values from 0.63 to 1.05，and 0.79 to 0.85，respectively，which means that the granite has weak negative anomalies of Eu and Ce.Th，U and high field intensity of Hf in the granite show relative enrichment，while Ba，Ni and Ti are at relative loss.The magma source of Qinggangping Granite is un-weathered igneous' remelting in the crust，and is formed in the post collisional orogenic environment as granites of type I. Qinggangping Granite|The ore-forming environment|Diagenetic mechanisms