豫西花山花岗岩基岩石学和地球化学特征及其成因

Petrological and Geochemical Characteristics and Genesis of the Huashan Granitic Batholith,Western Henan

花山花岗岩岩基是燕山期在华北地台南缘发生的陆内挤压俯冲作用的产物。组成该岩基的万村、蒿坪和金山庙岩体的矿物学、岩石化学、稀土及微量元素地球化学特征均可以与Ⅰ型（或华南同熔型）花岗岩相类比，反映出该地壳重熔成因的花岗岩对源岩──变质的中基性火山岩（太华群）的继承作用。因此，在划分花岗岩类的成因类型时，应考虑到其形成的地质背景、源岩性质及成岩方式等因素。

The Huashan granitic batholith in Xiongershan area,western Henan,is composed of three granitic bodies,i.e.Wancun biotite moyite-adamellite(γ),Haoping amphibole-biotite adamellite(γ)and Jinshanmiao moyite(γ).Being a product of Yanshanian intracontinental compression-subduction on the southern margin of the North China platform,the batholith was formed by remelting of the crystalline basement of this area(metamorphic rocks of Archean Taihua Group)under appropriate P-T conditions.The early stage Wancun granitic body represents the average composition of the remelted magma,whereas the late stage Jinshanmiao body might have been formed by crystallization differentiation of the middle stage Haoping granite body.Various stages of rock bodies making up the Huashang granitic batholith are comparable with I-type granites proposed by Chappe11(1974)or South China syntectic granites in mineralogy,petrology,geochemistry and stable iso-tope composition,but are obviously different from the South China transforma-tion type granites proposed by Xu Keqin et al.(1984)in spite of their similarity in petrogenic style.This is because the source rocks of the Huashan batholith are metamorphosed intermediate-basic volcanic rocks,suggesting that characteristics of granites formed by crustal anatexis depend to considerable extent on properties of source rocks.It is therefore concluded that in genetic classification of granites,their geological settings,properties of their source rocks and their petrogenic styles should be considered synthetically.