库鲁克塔格地区太古—古元古代“非史密斯”地层岩石化学特征及地质意义

NON-SMITH STRATUM PETROCHEMICAL CHARACTERISTICS AND GEOLOGICAL SIGNIFICANCE OF ARCHEOZOIC AND PROTEROZOIC ERA IN QURUQTAGH AREA

新疆库鲁克塔格地区位于塔里木盆地北东缘活动陆缘区,是我国前寒武系出露较典型地区.该区出露"非史密斯"地层有中新太古界达格拉格布拉克群TTG质片麻岩套(片麻岩SIMS锆石U-Pb年龄为(2 565±18)Ma)和古元古界兴地塔格群石英岩-云母片岩-大理岩建造(混合岩锆石U-Pb年龄值为(1 912±12.1)Ma),为片麻岩相-角闪岩相-绿片岩相变质岩.前者原岩以火山岩系为主,经热力变质作用形成,Na2O>K2O,为钠质岩石系列,δEu=0.401～0.973,为δEu负异常.后者原岩以沉积岩系为主,有厚达数百米碳酸盐岩层,主要为区域热流动力变质作用形成,K2O>Na2O,成熟度高,稀土分布模式为右倾型,分馏极好,LREE富集、HREE亏损,具δEu负异常,与元古界页岩分布模式相似,为典型沉积岩模式.

The study area is located in the northeastern of Trim basin, there is a typical area of Precambrian stratum. The non-Smith stratum includes Archeozoic Dagelagebulake group TTG rock series（hornblende Sm-Nd isochronal age is （3 262±129） Ma） and early Proterozoic Xingditage group quartzite-mica schist-marble rock association.Former＇s country rock mainly composed by volcanic rocks that is formed by thermal metamorphism, Na2O〉K2O,belong to sodium rock series,δEu=0.401-0.973,for the δEu negative anomaly;The latter＇s original rocks mainly composed by sedimentary rocks and a thick hundreds of meters of carbonate rock, mainly for the regional heat flow dynamic metamorphism,KEO〉Na2O, high maturity, their REE patterns for the right curve type, fractionation excellent, LREE enrichment, HREE lose, with δEu negative anomaly, and Proterozoic shale distribution pattern similar to the typical pattern of sedimentary rock.