Discussion On Late Permian Granodiorite Petrology Features And Tectonics Setting In Haerzhagai Of Inner Mongolia

Based on Hanggala-Haerzhagai regional geological surveys, the paper focus on the relationship between Haerzhagai magmatic rocks and its tectonic setting. With the analysis of macro geological features of Late Permian granodiorite and the data of petrology and geochemistry, discussing the effect of magmatic activity in process of plate collision, the paper provide the deep geological constraints and chronology evidence for the study of Haerzhagai regional structure and plate tectonics collision .There are a large area magmatic rocks occurred in the study area . Magmatic activity last from the pre-Cambrian to the Triassic, formed the intrusion of a different era and lithologies,and the Late Permian granodiorite occupies an area about a quarter of the region.Through the LA-ICP-MS method zircon U-Pb isotopic dating, The emplacement time of Haerzhagai Late Permian granodiorite was around 257-260 Ma.Through petrology and geochemistry analysis , the Haerzhagai Late Permian granodiorite magmatism is calc-alkaline magma series, with a strong fractional crystallization and magma mixing, from the upper mantle, with the role of subduction-related I -type granite.During the rising process, the molten magma of the earth’s crust containing hornblende.Through the major elements and trace elements in diagrams, geochemical analysis, we can see that in this area granodiorite belongs to the tectonic setting of volcanic arc series of the Department of calcium alkaline. Integrated Regional tectonic framework, mineralogical characteristics, and the mechanism of magmatic evolution ,we infer that Haerzhagai located in the island arc which built on the fragmentation crust in the Late Permian , in line with the regional tectonic position by Wang Tingyin (1998).The granodiorite forming when the Tarim plate subducting to the north China plate .