Geochemical characteristics and LA-ICP-MS zircon U-Pb dating of the Late Permian monzogranite in Hanggale, Alax Right Banner, Inner Mongolia

Late Permian monzogranite of Hanggale is characterized by rich alkali metals, poor MgO, TFeO and CaO, enrichment of LREE, and weak negative Eu anomalies, implying an I-type granite. The depletion of Nb, Sr, P, Ti elements shows that such an arc granite has features of intrusive rocks related to subduction. In the R1-R2 diagram, most of the samples are concentrated along the boundary between the pre-collision granite area and the post-collision granite area. In the Nb-Y diagram, the samples fall into the area of the volcanic arc-syncollisional granite. In the Rb-(Y+Nb)diagram, the samples lie in the area of volcanic arc granite. In the Rb-Hf-Ta diagram, the samples all fall into the arc system. High Th/U ratios in zircon of main rocks show characteristics of magmatic zircons; high total REE, heavy REE enrichment and left-oblique curves in the chondrite-normalized diagram are consistent with general characteristics of magmatic zircon distribution. LA-ICP-MS zircon U-Pb dating shows that its age is 253.5±7.9Ma. The Late Permian monzogranite of Hanggale was a pre-collisional volcanic arc granite, and Hanggale area was a volcanic arc that belonged to active continental margin in Late Permian.