东天山卡瓦布拉克喀拉塔格南岩群地质特征

EOLOGICAL CHARACTERISTICS FOR THE GROUP OF ROCKS IN SOUTHERN GELATAGE, KAWABULAKE, EAST TIANSHAN MOUNTAIN REGION

卡瓦布拉克大断裂北晚太古宙喀拉塔格南岩群,为灰色片麻岩系(TTG岩系)及二长-钾长花岗片麻岩系组成的高级变质区,后者常呈脉状或不规则状分布在TTG岩系中,构成灰、红相间的景观特征.岩石具高角闪岩相-麻粒岩相变质特征,发育中深层次的塑性流变变形,变质矿物有反条纹长石、钾长石、角闪石、铁铝榴石等,区域上还可见蓝石英、紫苏辉石、硅线石.经岩石化学研究,组成该岩群的片麻岩具英云闪长岩-奥长花岗岩-花岗闪长岩(TTG岩系)组合特征.该套变质岩系可与库鲁克塔格、尾亚、阿尔金等地太古宙中深变质岩系对比,时代厘定为晚太古代较恰当,构造属性为塔里木地块的前震旦纪结晶基底.

The Archean rocks of south Gelatage, north of the major Kawabulake fault, are highly metamorphosed grey gneisses series （TTG rock formation） and monzonitic potash granitic gneiss. The monzonitic potash granitic gneiss is dyke like within the TrG rock formation and shows grey and red interphase colors. The rocks are breccia-amphibolite and granulite facies metamorphism. The plastic metamorphic minerals in the middle and lower parts of the stratum are antiperthite, potash feldspar, hornblende, almandine and etc. In the same region, blue quartz, hyperstheme and sillimanite are found. Petrochemical studies show the gneiss has the combined characteristics of tonalite-diorite, trondhjemite and granodiorite （TTG rock formation）. The metamorphism of the rocks can be compared with the deep Archean metamorphic rocks in Kuluketage, Weiya and Arjin areas. The real age should be in late Archean, and the structure belongs to the early Sinian Period crystalline base of Tarim plot.