中文摘要：

在东北 Guangxi 的 Miaoershan 铀(U) 矿石地是在华南的重要花岗石相关的 U 存款之一并且是仔细与 Douzhashan 忍受 U 花岗石有关。Douzhashan 花岗石包含主要 U 富有的附件矿物质，包括独居石(UO2 = 0.981.75 wt%) 并且磷钇矿(UO2 = 1.486.14 wt%) 。231 ns 的主要独居石和磷钇矿收益化学药品年龄。在这研究，二中生代中间酸的恼人的岩石的 LA-ICP-MS 锆石地球年代学(包括 Shima 斑状的 granodiorite 和 Gaozi 石英闪长岩斑岩) 在 Ningzhen，区域系统地被调查。这些新 geochronological 数据证明在 Ningzhen 区域的中间酸的 magmatism 标明日期到近似在 109 和 101 妈之间。我们为 Cishantou skarn 的现在的新 40Ar-39Ar 金云母年龄熨抑制在 Ningzhen 区域预定 mineralisation 的沉积物。在 Cishantou skarn 沉积物的金云母产出 104 的 40Ar-39Ar 高原年龄

英文摘要：

The Miaoershan uranium （U） ore field in northeastern Guangxi is one of the important granite-related U deposits in south China and is closely related to the Douzhashan U-bearing granite. The Douzhashan granite contains primary U-rich accessory minerals, including monazite （UO2 = 0.98-1.75 wt%） and xenotime （UO2 = 1.48-6.14 wt%）. Primary monazite and xenotime yield chemi- cal ages of 231±28 Ma and 230 ±38 Ma by electron microprobe analysis and U-Pb isotopic ages of 220±6 Ma and 211±7 Ma by laser ablation-inductively coupled-mass spectrometry respectively. These ages demonstrate that the Douzhashan granite formed during the period of Indosinian magmatic activity. Back scattered electron imaging shows that monazite and xenotime are com- monly altered to assemblages of low-U synchisite and apatite, which was associated with loss of U to hydrothermal fluids. U-Th-Pb analyses of secondary apatite yielded a chemical age of 136± 17 Ma, which corresponds to the timing of Creta-ceous-Tertiary crustal extension in south China. We suggest that the heat and CO2 required for mineralization was the result of Yanshanian crustal extension, and that this triggered the breakdown of U-rich accessory minerals in the Douzhashan U-bearing granite. Uranium remobilization from the Douzhashan granite provided materials for mineralization within the granite and/or surrounding country rocks. Therefore, a combination of Indosinian compression and Yanshanian extensional overprint produced the hydrothermal U deposits associated with the Douzhashan granite.