Analysis on Resource Potential of Xiahe-Hezuo Au Enrichment Area, Gansu: Taking Geochemical Blocks f Au, Ag and Sb as an Example

Au enrichment zone in Xiahe-Hezuo of Gansu Province is located in the west section of Qinling orogenic belt, where the geological condition is complicated, with major outcropped strata including Carboniferous, Permian, Triassic and Paleogene.In Yanshanian and Indosinian, the intermediate-acid magma intrusive activity is intensive. The faults are mainly overthrust strike-slip faults, with occurrences of secondary fractures and interlayer fracture zones. 47 mineral spots were identified, among which there are 3 large-scale occurrences, 3 middle-scale and 41 small-scaledeposits, indicating great potential for prospecting. Based on the theories and method of geochemical blocks, the authors confirmed geochemical blocks of Au, Ag, Sb and anatomized its structure with GeoMDIS and geochemical data handling.Abnormity conversion from regional to local was studied, family tree of elements geochemistry was established, and the mineralization track of each sub-block was recovered. Results show that the high Au value area is large; blocks of each level concentrate significantly to form Au geochemical province, which is spatial overlaid and combined with Ag and Sb blocks. It is calculated that the total of light gold within 500 m is 1000 t, with the geochemical block characteristics of large and ultra-large gold deposit. The ore-forming geological conditions in the study area is favorable;evaluation on Au resources potential has important significance for mineral resources evaluation and exploration.