Meitan xuebao (Sep 2023)
Control of tectonic uplift and denudation on uranium mineralization in the eastern Junggar Basin
Abstract
There is a close dynamic coupling relationship between tectonic and mineralization. Long-term research and observation have found that the formation and location of sandstone-type uranium deposits are obviously controlled by the formation of target layer and the subsequent tectonic uplift and denudation events. In order to describe the formation mechanism and process of different types and horizons of uranium deposits in detail and more reasonably, realize the transformation from theoretical model to prospecting model, and establish a new method and approach for target prediction that can be easily applied, a series of studies has been carried out on the uranium deposits (points) around the Kalamari Mountain in the eastern part of Junggar Basin. The study adopts the methods of the basin structural framework division, the research on burial and denudation history and the apatite fission track simulation in the source area. It is found that different types of uranium deposits (spots) in the periphery of the Kalamari Mountain are different products of the same metallogenic system, namely, uplift and denudation evolution. The basin subsidence curve and apatite fission track simulation in the source area show that the eastern Junggar basin has experienced 160−140, 90−70 Ma and about 20 Ma three rapid uplift and denudation stages since the Middle and Late Jurassic. These tectonic events have induced obvious uranium mineralization. The scale and stage of uranium mineralization are controlled strictly by the intensity and stage of tectonic uplift and denudation. In the process of uranium mineralization, tectonic development and evolution play a leading role. Large-scale uranium mineralization is mainly developed in the structural slope zone with a complete mineralization system. For example, the Kamusite progradation (denudation) multi-period same-direction superposition and the Beisantai retrogradation far source uranium mineralization model can often form some large-scale deposits. In general, a large-scale uranium mineralization will not develop in the sections with complex and variable structural forms, such as the piedmont area at the southern edge of the Kalamari Mountain. The summary of the above regional tectonic uplift, uranium mineralization sequence and ore-control combination provide a scientific basis for the prediction of uranium mineralization prospect in this area, and can be applied to the prospecting of sandstone-type uranium deposits in other basins.
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