Metallogenesis and Geodynamic Setting of the Early Paleozoic Orogenic Gold Deposits in the North Altyn

The North Altyn has underwent a complex tectonic history in the Early Paleozoic and formed a number of orogenic gold deposits controlled by ductile to brittle shear zones adjacent to the southern side of the Northern Altyn Tagh fault e.g. the Dapinggou, Beiketan and Xiangyun. The Dapinggou gold deposit, a typical orogenic gold deposit in North Altyn, is predominantly hosted in the Precambrian carbonate and Cambrian volcano- sedimentary rocks which were strongly deformed and were subjected to low-grade metamorphism. The ore bodies occurred in K-feldspar quartz veins and hydrothermally altered mylonite within the ductile shear belt. Hydrothermal alteration including silicification, pyritization.

Early Paleozoic Magmatism and Crustal Evolution in the North Qinling Orogen

1 Introduction The North Qinling orogenic belt is characterized by diverse rocks,multi-phase tectonic-magmatic events,which is composed of not only basement rocks of the Qinling Group,but also numerous magmatic rocks in