The Westmoreland area is located in the southern part of the McArthur Basin (Australia) and hosts several uranium (U) deposits and prospects. Previous studies proposed that U mineralisation formed under conditions similar to the unconformity-related U deposits of the Alligator Rivers Uranium Field (ARUF), located north of the McArthur Basin. Detailed mineralogical, geochemical and geochronological studies on mineralised intervals from the Redtree, Junnagunna, and Huarabagoo deposits, and integration with previous studies, identified at least six generations of uranium oxides. These formed between ca. 1680 and 350 Ma, highlighting protracted mobility of U over 1.3 Ga. Each generation of uranium oxide has a specific chemical composition, indicating variable physicochemical conditions for their formation throughout this period. Although the 1680-Ma mineralising event formed at the same time and with similar mineralising fluids as the unconformity-related U deposits from the ARUF, the physicochemical conditions differed between the two areas. Deposits of the Westmoreland area lack the typical Mg– and B–metasomatism of the unconformity-related U deposits in the ARUF: in the Westmoreland area, the chlorite is Mg-poor and no B minerals are observed, whereas the ARUF is marked by Mg-rich chlorite, between clinochlore and Mg–amesite, Mg–foitite, and alumino–phosphate–sulfate minerals. The chondrite-normalised REE patterns of uranium oxides are enriched in light rare earth elements (LREEs) or flat, compared with the typical bell shape of the unconformity-related U deposits. Chlorite thermometry indicates significantly higher temperature conditions (> 300 °C) than in the ARUF for the early U stages. Based on these results, mineralisation in the Westmoreland area is thus significantly different from the unconformity-related U deposits in the ARUF and in other sedimentary basins. Collectively, the data point towards atypical ore-forming processes for basin-related U deposits in the Westmoreland area, but show some similarities with those known in the U deposits of the Otish Basin (Québec, Canada).

中文翻译：

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威斯特摩兰地区（澳大利亚麦克阿瑟盆地）铀迁移率和沉积超过 1.3 Ga

威斯特摩兰地区位于麦克阿瑟盆地（澳大利亚）的南部，拥有多个铀 (U) 矿床和远景。先前的研究表明，U 矿化形成的条件与位于麦克阿瑟盆地北部的鳄鱼河铀矿场 (ARUF) 的不整合相关 U 矿床相似。对 Redtree、Junnagunna 和 Huarabagoo 矿床的矿化层段进行详细的矿物学、地球化学和地质年代学研究，并与之前的研究相结合，确定了至少六代铀氧化物。这些形成于约。1680 和 350 Ma，突出了 U 超过 1.3 Ga 的长期迁移率。每一代氧化铀都有特定的化学成分，表明在此期间它们形成的不同物理化学条件。尽管 1680-Ma 矿化事件与 ARUF 的不整合相关 U 矿床同时形成并具有相似的矿化流体，但两个地区的物理化学条件不同。Westmoreland 地区的矿床缺乏 ARUF 中与不整合面相关的 U 矿床的典型 Mg-和 B-交代作用：在 Westmoreland 地区，绿泥石贫镁且未观察到 B 矿物，而 ARUF 以 Mg 为标志- 富含绿泥石，介于斜绿石和镁铁矿、镁铁矿和铝磷矿硫酸盐矿物之间。与不整合相关 U 矿床的典型钟形相比，氧化铀球粒陨石归一化的 REE 模式富含轻稀土元素 (LREE) 或平坦的。绿泥石温度测定表明温度条件明显较高 (> 300 °C）比早期 U 阶段的 ARUF 高。基于这些结果，Westmoreland 地区的矿化因此与 ARUF 和其他沉积盆地中与不整合相关的 U 矿床显着不同。总的来说，数据表明 Westmoreland 地区与盆地相关的 U 矿床的非典型成矿过程，但与 Otish 盆地（加拿大魁北克省）的 U 矿床中的已知矿床有一些相似之处。