Geology and metallogenesis of Liba large-size gold deposit in Lixian, Gansu province.

Radiometric dating and isotope analysis indicate an age for the deposit consistent with that of the Dashan granite and an ore-forming fluid derived mainly from magmatic and geothermal water. The background Au value of Middle to Upper Devonian sediments in the Lixian-Minxian area where the deposit is located is higher than values of the sedimentary cover and upper crust of the western Qinling Mountains in general. It is thought that the Zhongchuan granite provided the heat source and the main water source for Au mineralisation, circulation of the fluid through the Devonian sediments giving rise to the ore-forming solution and early structures acting as a conduit to later deposit-controlling structures.
Radiometric dating and isotope analysis indicate an age for the deposit consistent with that of the Dashan granite and an ore-forming fluid derived mainly from magmatic and geothermal water. The background Au value of Middle to Upper Devonian sediments in the Lixian-Minxian area where the deposit is located is higher than values of the sedimentary cover and upper crust of the western Qinling Mountains in general. It is thought that the Zhongchuan granite provided the heat source and the main water source for Au mineralisation, circulation of the fluid through the Devonian sediments giving rise to the ore-forming solution and early structures acting as a conduit to later deposit-controlling structures.