Tectonic‐magmatic framework identified by remote sensing analyses and geochronology in West Junggar, Central Asian Orogenic Belt

Abstract

The temporal and spatial evolutions of the Darbut Fault deformation patterns were analysed for multiple deformation stages in this study by using a regional geological survey, quantitative remote sensing image analyses, and structural analyses. Remote sensing images indicating that the Karamay granitoid batholith is greenish‐grey, the Hongshan granitoid batholith is yellowish‐green along the Darbut Fault, and the Miaoergou, Akebasitao, and Hatu granitoid batholiths are round in shape and luminous yellow colour. The remote sensing images of the Darbut Fault, Hongshan granitoid batholith, and data from previous research suggest that the upright folds (F1) in the Carboniferous strata near the Darbut Fault and northeast‐southwest (NE‐SW) striking sub‐vertical dextral shear zones in the mélanges represent the regional dextral strike‐slip shear zones. The NE‐SW striking transcurrent sinistral strike‐slip faults and ‘S‐shaped’ drag folds (F2) overprinted the dextral shear zones. The Hongshan batholith is a complex pluton, which was composed of alkaline feldspar granite, syenite granite, and monzogranite. The LA‐ICP‐MS U–Pb 311–307 Ma of zircons from the ductilely deformed Hongshan alkaline feldspar granite and monzogranites are formed during the dextral shear zone of the Darbut Fault. The 302 Ma Hongshan alkaline feldspar granite is contemporarily formed during the sinistral strike‐slip stage of the Darbut Fault. The Hongshan complex pluton has a prolonged formation age and witnesses the whole process of ocean‐land conversion from the capture of island arc‐related rocks, granite formed in the post‐collision stage, and dyke swarms formed in the intracontinental extension stage.