| The Qin nan district is located in the northern of the Xiaoqinling gold district. This paper collected the research results of previous studies. The thesis carried out detailed studies on geological characteristics of ore deposits and mineralization, ore-controlling factors and metallogenic regularities, based on field geological survey and indoor comprehensive analysis on the data.The structure, strata, magmatic activity and wall rock alteration in Qin Nan area are studied. The orebodies, ores and types ores are characterized. It is shown that the the Qin Nan gold mineralization occurred at ca. 120 Ma, i.e. at late Yanshannian. The ore-forming elements such as Au, S and Pb are suggested to be derived from deep crust or upper mantle, which is closely related to the Archean greenstones and Yanshanian tectonic- granitic magma activities. The ore-controlling factors and mechanisms of mineralization are discussed in the thesis. The Xiaoqinling greenstones are the important source rock of mineralization.Fratcutes in the ore-bearing tectonic belt and quartz veins formed at different stages of tectonic activities are the major controlling factor of the different stages of gold mineralization. The Yanshanian granitic intrusions not only provided the gold mineralization fluids and thermodynamic conditions, but also provided the sources of mineralizing elements;The Qin Nan gold mineralization in the main metallogenic stage(Ⅱ, Ⅲ) occurred at temperatures of 283 ~ 153 ℃, which imply that the temperatures of the ore deposit formation belong to the medium and low temperature, but give priority to with medium temperatures.The Qin Nan gold mineralization belongs to the medium-low temperature hydrothermal vein deposit formed by magmatic fluids. |
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