Abstract: Western Qinling is one of the most important gold producing regions in China. Except for a few skarn-type gold deposits, almost all gold deposits are classified as orogenic, Carlin-type or Carlin-like gold deposits. Mesozoic granitoids in the region emplaced during the Middle-Late Triassic while gold deposits formed during the Late Triassic—both are the product of Qinling Orogenesis caused by the final collision between the North and South China Blocks. Orogenic gold deposits are confined to NWW-trending brittle-ductile shear zones in Devonian and Carboniferous greenschist-facies metasedimentary rocks that were highly-deformed and regionally-metamorphosed. The deposits show a close Au-Ag association. Ores contain mainly microscopic gold, electrum and visible gold, along with pyrite. The ore-forming fluids are mainly metamorphic fluids. Intensive tectonic movements caused by orogenesis create fluid-migrating channels as precipitation sites. Although some orogenic gold deposits occur adjacent to granitoids, mineralization is not synchronous with magmatism. The Carlin-type deposits are mostly hosted in slightly metamorphosed Cambrian to Triassic sedimentary rocks, showing stratigraphically, lithologically and structurally controlled features. The deposits mainly contain submicroscopic and solid solution gold in arsenian pyrite and arsenopyrite, with characteristic ore-forming element of Au-As-Hg-Sb-Ba. The ore-forming fluids are early-stocked formation water and later-recharged meteoric water, and partially from the magmatic water or metamorphic fluids. Meteoric water apparently evolved in ore-forming fluids by circulation, indicating the extensional setting; it led to the deposition of Au and other elements in cool reactive permeable rocks at shallow levels to form the disseminated ores. Carlin-like gold deposits mainly formed from shallow sedimentary rocks through metamorphism. They are controlled by brittle-ductile shear zone and occur adjacent to granitoid plutons. The most important characteristics of Carlin-like gold deposits, differing from orogenic and Carlin-type gold deposits, is their genetic relationship with synchronous magmatism. Gold occurs as microscopic gold. Pyrite, arsenian pyrite and telluride can be recognized as gold-bearing minerals. The ore-forming fluids are mainly magmatic water mixed with metamorphic and/or formation water. Similar to orogenic gold deposits, fluid immiscibility led to the formation of Carlin-like gold deposits.

Key words:  West Qinling, gold deposit type, metallogenic charateristics, mineralization