Geochronology And Its Geological Implications Of Late Carboniferous Tectonic Magmatic Belt In North Of Hegenshan Tectonic Zone

The research area is located in the north side of Erenhot-Hegenshan ophiolite belt in the Xingmeng Orogenic belt. In the north side of Erlian-Hegenshan ophiolite belt widely developed Late Paleozoic tectonic magmatic belt. Porphyry rock and the coarse-grained granodiorite accurate geochronology and geochemical study and combined with previous data systemaicly. It is study intrusive rocks in northern Hegenshan tectonic zone genesis and its tectonic background. It is provide new evidence for the Siberian Plate and North China Plate final closure time and its collision evolution history. In the paper, the Late Carboniferous intrusive rocks in Hegenshan are located in Dalaisumu, it is fine-grained granodiorite and granite porphyry. LA-ICP-MS U-Pb dating yielded ages of 328 ± 2 Ma and 304 ± 2 Ma for medium fine grained granite and granite porphyry. The rocks are enriched in SiO2(67.91 %~71.98 %),Al2O3(14.04 %~14.85 %)and TiO2(0.32 %~0.37 %).It has A / CNK(0.95~1.03)defined metaluminous or peraluminous.Combined with previous data,there are 330 Ma~300 Ma Carboniferous intrusive rocks in northern Erlian-Hegenshan ophiolite. It is mainly in alkaline calcium or high K calc-alkaline series characteristic.It has I-type granitec magma belt in northern Erlian-Hegenshan ophiolite. The reason is that land collision docking role cause a lot of Paleozoic magmatic rocks in Erenhot-Hegenshan ophiolite belt which as the late Paleozoic suture zone boundary.