Geological characteristics and metallogenetic model of Zhuguang uranium ore concentrated area

The authors mainly discuss the geological background and metallogenic mechanism of large and high-grade uranium deposits in Zhuguang region. New progresses have been made in regional metallogenic regularities and metallogenic theories and a series of new outcoming have been achieved: (1) The pre-Sinian uranium-rich crystalline basement aged at 1.9-2.2 Ga has been determined in the region for the first time. The discovery contributes greatly to the uranium metallogenic potential in Zhuguang area. (2) For the first time, authors propose that uranium and material sources in Zhuguang region were mainly derived from the uranium-rich thermal fluid chambers of crust-mantle mixed-melting origin, rather than from the wall rocks of uranium deposits, as considered by traditional views. (3) The stage and sequence of magmatic activity, and genetic type of magmatic rocks in Zhuguang region have been redetermined. (4) Four NE-trending tectonic belts, i. e. Nanxiong, Baishun, Changjiang and Jilong have been determined as Mesozoic extensional taphrogeny zones, which are the regional crust-cutting tectonic belts controlling the basins, magmatic activities and uranium mineralization. (5) For the first time, uranium deposits in Zhuguang region are divided into two types: the pneumatolytic-hydrothermal fracturing alteration-micro vein dissemination type uranium deposits and the vein-filled type uranium deposits. And a deep-sourced metallogenic model of uranium deposits in the region has been set up.