Geological Characteristics And The Discussion Of The Age Of Xingxingxia Rock Group Of Kalatage Area In Eastern Tianshan, Xinjiang

This dissertation mainly research the distribution condition and rock association and structural characteristics etc of Xingxingxia rock group of Kalatage area in Eastern Tianshan and re-division original Xingxingxia group, determined its formation age then approaches its ownership of tectonic unit which based on macroscopic grasping the latest research results and research progress in Eastern Tianshan and comparative analysis every formations in regional, collected mainly regional research results of stratigraphy,petrology, structural geology and isotopic dating.Though the field investigation and laboratory study Xingxingxia group is disintegrated, after disintegration original Xingxingxia group is divided into three parts which are Bowamu group,Xingxingxia rock group and metamorphic pale-intrusions.Xingingxia rock group is divided into "a" and "b" informal rock sections which based on extent relative of stability of sedimentary environment.The contact relationship of the two rock sections is structural foliation which have no upper and lower relationship in sequence. Though the study on the metamorphism and deformation characteristics of Xingxingxia rock group which is the real crystalline basement formation, the author considered that Xingxingxia rock group is metamorphic strata geological body which has the amphibolite-high amphibolite facies.The two rock sections are the metamorphic rock series which experienced deep tectonic level deformation and its metamorphic grade is high amphibolite facies.In the way of LA-ICP-MS the author obtained U-Pb Isotopic age of 2452±66 Ma and 1965±58 Ma from ancient metamorphic rock intrusion (Granodiorite gneiss) which had inwaded into The Xingxingxia rock group,so it provided a direct evidence for dating the age of The Xingxingxia rock group. Meanwhile, the Isotopic age of the Granulite. which was discovered in the west of Longtou mountain, is 2390±40 Ma, The mensuration data mentioned above proved a fact that this aera got thought a large scale magma intrusion at 2400 MaIt have great different between Xingxingxia rock group and Changchengian Period formation in area though regional correlation. But it is similar to archean rocks. Combined with the data of isotopic age, the author considered that the age of Xingxingxia rock group is from neo-archaean to palaeoproterozoic. Precambrian basement in Eastern Tianshan is very similar to archean rocks in Kuluketage area. North edge of Tarim at the sections of rock association, deformation metamorphic characteristics, tectonic environment and evolution history etc.