The Aobaohuturen porphyritic syenite granite，intruded into the Beishan Group and the Early Paleozoic granite，outcrops in northwest of Shibanjinin Beishan area，Inner Mongolia. Major elemental analyses of the granite show that Ti is characterized by high contents of SiO2 （70.41%～76.05%） and K2O （3.85%～5.22%），and it has high K2O/ Na2O ratio （1.42～2.23），an A/CNK ratio of 0.97～1.10，and MgO# values of 14 to 32. REE study indicates that the granite is enriched in light rare earth elements( (La/Yb)N = 11.06～18.54) with high total rare earth elements （ΣREE = 179.21 × 10-6～332.23 × 10-6）. Meanwhile，the Chondrite-normalized distribution curve is right inclined with significant negative Eu anomaly （δEu = 0.25～0.75）. The granitic rocks are enriched in high ion lithophile element （e. g. Rb、Th and K），but depleted in Nb，Ta，Sr，P and Ti. Zircon LA-ICP-MS U-Pb dating yield edanage of 398.15 ±0.85 Ma，respectively，indicating that the Aobaohururen granite was formed during the Early Devonian. The values εHf(t) of porphyritic syenite granite ranges from 0.3 to 7.8 with the two-stage Hf model ages （tDM2） of 1 376～894 Ma. All these characteristics indicate that the porphyritic syenite granite was formed in an extensional tectonic setting during the Early Devonian，and sourced from partial melting of cal-alkaline granodioritic protholiths derived from melting of a young crust，and it then experienced strong differentiation.
Pan Zhilong Zhang Huan Chen Chao Wang Shuo Zhang Jinlong Tian Fenying Liu Ce Zhang Liguo Li Qingzhe. Zircon U-Pb geochronology and Lu-Hf isotope compositions of porphyritic syenite granite from Aobaohuturen in Beishan，Inner Mongolia and its tectonic implication[J]. Chinese Journal of Geology, 2017, 52(1): 301-316.