Discussion on geological and structural characteristics and associated metallogeny in northeastern Hunan Province, South China

The Jiangnan Orogen has been generally considered as a transitional zone between the Yangtze Block and the Cathaysia Block. The evolution of Jiangnan Orogen led to the significant difference of the space-time of the tectonic deformation, which determines the complexity of the gold and gold-polymetallic mineral resources. By the comprehensive analysis of regional geological characteristics, ore-controlling structural features, geological features of the typical deposits, regional tectonic evolution and associated metallogeny, this paper holds that: (1) regional tectonic background was the basis for development of ore field structure, the key to form the structure pattern in NE Hunan Province, South China, was the compressive stress field in Indosinian and the extension in Yanshanian made the area into a mineral-rich mineralization occurrence; (2) the ore field structure dominated by NE(NNE) led to the construction of complex EW- and near EW-trending structures, multi-stage tectonic activities created the district, which formed NW-trending folds and NE-trending fault system and a structural framework that features" two uplifts, three basins" was presented; (3) the main ore-controlling structure style is the ductile shear; (4) the state of ore body was closely related to the evolution and composition of tectonics and the current occurrence status of the mineral resources were limited by the deformation and superimposed on transformation. Finally, according to the geological characteristics of the deposits, combined with regional tectonic evolution, we have proposed the metallogenic model of Au and Au-polymetallic mineralization in the Jiangnan Orogen domain in the Hunan.