Geochemical Characteristics Of Volcanic Rock In Song Jiang Region,Heilongjiang

According to "1:50000 survey of mineral resources in the three maps including Liaodian,Songjiang,Quanxiao,heilongjiang province". Collecting results of previous people studies and field geological survey and laboratory research work, we made the following findings:1.Volcanic strata were divided in Songjiang of Heilongjiang, determined the study area of volcanic stratigraphic sequence, using the method of zircon U-Pb dating to determine the formation age of the study area Tang jiatun group volcanic rocks is Late Carboniferous epoch.2. Study area of Tang jiatun group, Mao'er mountain group, Ningyuan village group volcanic rocks petrology and geochemistry characteristics were studied, Tang jiatun group volcanic rock types are mainly alkaline series, Mao'er mountain group, Ningyuan village group volcanic types are mainly high-potassium and high- calcium alkaline series. Rare earth element analysis results for the three groups of volcanic rocks are which Eu is negative anomaly and rare earth element pattern is rightist type; three groups of volcanic rock trace element analysis results are enriched in large iron lithophile elements and depleted in high field strength elements respectly.3.Volcanic tectonic environment in the study area were analyzed, the preliminary view that middle variscan period(Tang jiatun group volcanic rocks) in the study area are formed in Jiamusi terrain and Songnen-Zhangguangcai ridge terrain collage squeeze occurs continental-continental collision orogeny activities, and in the late orogenic activity, due to the release of squeeze pressure, gradually transformed into the stretch environment, along with thinning crust, enter into the post-orogenic extension phase; Yanshan period(Mao'er mountain group volcanic rocks, Ningyuan village group volcanic rocks) tectonic environment in ancient Asia Pacific plate and ancient oceanic plate collision late orogenic activity, is active continental margin tectonic environment.