引用本文：高峰,郑常青,姚文贵,李娟,施璐,崔芳华,高源,张行行.2013.大兴安岭北段扎兰屯哈多河“花岗质糜棱片麻岩”年代学及地球化学特征研究[J].地质学报,87(9):1277-1292. gaofeng,zheng changqing,yao wengui,lijuan,shilu,cuifanghua,gaoyuan,zhangxingxing.2013.Geohronology and Geochemistry Characteristics of Granitic Mylonitic Gneiss in Zhalantun Haduohe Area of the Northern Great Xing’an Range[J].Acta Geologica Sinica,87(9):1277-1292.
Abstract:The granitic mylonitic gneiss is a set of metamorphic granitic rocks, located in Haduohe area, is mainly composed of fine grained biotite monzonitic granitic mylonitic gneiss, fine grained biotite granitic mylonitic gneiss and fine garnet mica granitic mylonitic gneiss. The results of geochemical study indicate that SiO2 values are in the range of 66.4%~74.52%, K2O+Na2O is between 7.36%~8.84%, Al2O3 values are in the range of 13.43%~15.74%, A/CNK=0.974~1.092, belonging to high-K calc-alkaline and quasi-aluminous to weakly peraluminous rocks; It’s higher in total rare-earth content (ΣREE= 94.15×10-6~164.30×10-6), the chondrite -normalized REE patterns demonstrate right-oblique linear REE patterns with weak negative Eu anomalies, and reveals LREE enrichment and HREE depletion; The trace element is characterized by a strong enrichment in large ion lithophile elements, such as Rb, Ba, U, K et al, depletion in Ta, Nb, P, Ti et al.. The zircon U-Pb dating results indicate that the magma formation can be divided into two periods, the first period is around 320Ma, the representative rock is fine grained biotite granitic mylonitic gneiss and fine garnet mica granitic mylonitic gneiss, the second period is around 304Ma, the representative rock is fine grained biotite monzonitic granitic mylonitic gneiss. Combining petrography, chronology and rock geochemical characteristics, the protolith of the granitic mylonitic gneiss is high-K calc-alkaline I type granite, formed in the post-collision environment of Xing'an block and Songnen block, during Late Carboniferous. And then suffered relatively strong ductile brittle metamorphism and deformation during Late Early Permian by the post-collision of Xing’an block and Songnen block.