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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.

Xiaogouli, Gansu, differs in many ways from the Carlin-type deposits of the Qinling orogenic belt. Au-bearing quartz lodes with visible and coarse-grained gold up to 3 mm in diameter extend through mid-Devonian siltstones, phyllites and silicalites. The ores consist of pyrite, pyrrhotite, arsenopyrite, sphalerite and galena. Well developed dykes commonly constitute the footwall and hangingwall of the orebodies. Radiometric dating, stable isotope analysis, trace element geochemistry, and the mineralogy and texture of spots in the Au-bearing rocks indicate that the Dashan granite was closely related to the deposit, providing its heat source, water source and part of its ore-forming material., Xiaogouli, Gansu, differs in many ways from the Carlin-type deposits of the Qinling orogenic belt. Au-bearing quartz lodes with visible and coarse-grained gold up to 3 mm in diameter extend through mid-Devonian siltstones, phyllites and silicalites. The ores consist of pyrite, pyrrhotite, arsenopyrite, sphalerite and galena. Well developed dykes commonly constitute the footwall and hangingwall of the orebodies. Radiometric dating, stable isotope analysis, trace element geochemistry, and the mineralogy and texture of spots in the Au-bearing rocks indicate that the Dashan granite was closely related to the deposit, providing its heat source, water source and part of its ore-forming material.

The studies show that albite in the deposit, which is in the northern part of the Fengtai orefield, formed volcanically and was recrystallised by metamorphism. This indicates that volcanic sedimentation was an important prerequisite for the formation of large gold deposits in the area; an important prospecting indicator seems to be the association of albite-bearing silicolites, phyllites and limestones., The studies show that albite in the deposit, which is in the northern part of the Fengtai orefield, formed volcanically and was recrystallised by metamorphism. This indicates that volcanic sedimentation was an important prerequisite for the formation of large gold deposits in the area; an important prospecting indicator seems to be the association of albite-bearing silicolites, phyllites and limestones.

The deposits, of the reformed sedimentary type, are hosted by Middle-Upper Devonian basin strata. There are two main types of Pb-Zn deposits and three types of Au deposit. Changbai-type Pb-Zn deposits are located in areas of strong metamorphism and weak deformation, whereas Dengjiashan-Bafangshan-type deposits are found in areas of strong deformation and weak metamorphism. Microscopic gold is disseminated in turbidites in Liba-type deposits and in albite-carbonate breccias in Shuangwang-type deposits, while Baguamiao-type deposits are fine quartz veins in weakly metamorphic fine-grained clastic rocks. There is a close temporal and spatial relationship between the Baguamiao- type Au and Dengjiashan-type Pb-Zn deposits., The deposits, of the reformed sedimentary type, are hosted by Middle-Upper Devonian basin strata. There are two main types of Pb-Zn deposits and three types of Au deposit. Changbai-type Pb-Zn deposits are located in areas of strong metamorphism and weak deformation, whereas Dengjiashan-Bafangshan-type deposits are found in areas of strong deformation and weak metamorphism. Microscopic gold is disseminated in turbidites in Liba-type deposits and in albite-carbonate breccias in Shuangwang-type deposits, while Baguamiao-type deposits are fine quartz veins in weakly metamorphic fine-grained clastic rocks. There is a close temporal and spatial relationship between the Baguamiao- type Au and Dengjiashan-type Pb-Zn deposits.

Lead isotopes are very similar in the gold deposits in Yanshanian granites and the Archaean metamorphic rocks of the Taihua Group along the south margin of the North China Platform. The isotope properties suggest that they come from a deep source. It is suggested that the isotopes separate from a unified source and concentrate to form gold deposits and are contaminated by lead isotopes from the crust at different times. The isotopes prove that metallisation is complex and polyphase and there are multiple deposit origins., Lead isotopes are very similar in the gold deposits in Yanshanian granites and the Archaean metamorphic rocks of the Taihua Group along the south margin of the North China Platform. The isotope properties suggest that they come from a deep source. It is suggested that the isotopes separate from a unified source and concentrate to form gold deposits and are contaminated by lead isotopes from the crust at different times. The isotopes prove that metallisation is complex and polyphase and there are multiple deposit origins.