Research On Petrogeochemistry Of Magmatite In North Section Of East Junggar Of Xinjiang Province

According to plate tectonics, the study area is located in the world’s second-largest orogenic belt, Ural-central Mongolia orogenic belt,which is more typical of the global collisional mountain regions, also the Siberian plate and the plate occupies a position of Kazakhstan, Tianshan-part of the Xing’an geosynclinal fold region. Outcropping strata, the Lower and middle Devonian, lower and middle Carboniferous, followed by the Ordovician, Cenozoic wide distribution.The area Kekekuduke, Aketasi, Kenaite are in the north of East Junggar,where we study the volcanic and granite is the great significance for north of East Junggar division and attribution.This paper summarizes the information and achievements on the basis of their predecessors to analysis some problems through the theoretical and methodological of petrography, mineralogy, mineral deposit geology, geochemistry, isotope geology and other disciplines of volcanic and granite in Kekekuduke、 Aketasi、Kenaite. This paper summarizes the characteristics of rocks of the study area, geochemical characteristics, age characteristics through Observational studies and geochemical methods outside and indoor.According the figures of TAS,SiO2-AR,A/NK-A/CNK,K2O-SiO2 and the identification of rock and mineral,We know the Kekekuduke and Aketasi volcanic are mainly mafic- neutral Magmatic.The volcanic are quasi-aluminum, alkaline -calc-alkaline-potassium calc-alkaline - shoshonitic basalt - andesitic basalt - trachyte- trachyandesite - rough dacite series in further quantitative research. The rocks of Kenaite are mainly calc-alkaline metaluminous - peraluminous granite - granodiorite-diorite.The chondrite distribution patterns shows that the relative distribution of light rare earth tilted relatively flat and the HREE distribution value shows the level of the basic state. The LREE and HREE Fractionation is weak even not differentiation.The diagram of mantle normalized of trace element spider showed rightist "W" type, from left to right, showing divergent trend towards centralized distribution; relatively enriched rocks, U, Pb, significant positive anomalies; relative loss Th, Nb, Ce, Pr, significant negative abnormal, showing the characteristics of island arc magma.The rocks are enriched, U, Pb, which are significant positive anomalies;but relative loss Th, Nb, Ce, Pr, significant negative abnormal, showing the characteristics of island arc magmas.The magmatic 206Pb/238U age weighted average 388.0Ma ± 6.7Ma, 303-397Ma etc.indicating major volcanic events in the Late Paleozoic formation of Devonian, Carboniferous.The Island arc volcanic rocks derived from the water-rich fluid formed by the subducting plate dewatering fluid account of partial melting of mantle wedge,which depleted in high field strength elements.Magmatic rocks are mantle-derived magma product, and there may be contaminated by crustal material.