Study On The Relationship Between Structure And Uranium Mineralization In The Gaoting Area Of Dayu County, Jiangxi Province

Based on former research, this paper researches how the structures in this study area effects uranium mineralization. On the basis of field geological investigation and indoor microstructure analysis, the author confirms the geometric and kinematic characteristics of the major structures in Gaoping. By the study of structure stress field, age of late dikes, fault styles and fault interspersed relationship, analyses the evolutions of the major structures in this zone. By the geochemical analysis of different kinds of tectonites in fault zones, the material components migration characters of Huangxi structure and Chengongao structure have been recognized. At last, the author combined with the data obtained by deep drillings and the latest research achievements discusses the relationship between structure activities and uranium mineralization.By two years research work, the main achievements obtained in this paper are as follows:(1) There are two large-scale NNW trending fracture and alteration belts(6 fracture and alteration blet and 8 fracture and alteration belt) in Shizai area, Gaoping zone, not just only several small-scale faults, it has good ore-probing future in this area. It has been confirmed that there is a NNW trending silicified belt on the west side of 6 fracture and alteration belt along a gully at the first time, and the exist of this belt just explain a closely SN trending U-components abnormal halo here.(2) There is a deep study on the form and size, movement mode and evolution process of closely SN trending fracture and alteration blet in the middle of reaserch area. The study shows that fracture activities here are more complex than other places, SN trending fracture and alteration belt had been cut by NEE trending Huangxi secondary fracture and alteration belt, and its occurrence has comparatively large variation.(3) Zircon LA-ICP-MS U-Pb dating method and uraninite U-Pb dating method have been used in dating age of the fine-grained granite from drillings. The results show that they are formed in Indo-Chinese epoch, not formed in Yansha epoch, confirm that this zone had been influenced by SN-trending compressional tectonism in Indo-Chinese epoch.(4) Combined with field geological investigation and indoor comprehensive analysis, three aspects of fractures control on uranium mineralization as follows: a) Fracture activity periods control uranium mineralization stages, namely ore fluid has different migration directions under different structure stress fields; b) Shear structural planes of NEE trending Huangxi structure is benefited to form ore body, if overlaid with extensional fracture activity, it is benefited to form rich and large uranium orebody; c) SN trending fractures and alteration belts could be good zone for forming ore body because of the change of its mechanical property and movement mode under different structure stress fields.At last, on the basis of the full use of all kinds of geological and geophysical materials and systematic field geological investigation, the author forecast the deep zone of the east Huangxi Fracture belt, the middle zone of Huangxi Fracture belt, NNW trending fractures in Shizai area and other some good zones should be the main targeting area for exploration...