The Thelon Basin, Nunavut, Canada, is similar in age, size, and geology to the U producing Athabasca Basin in Saskatchewan. The Kiggavik project area, located immediately south of the Aberdeen sub-basin of the Thelon Basin, contains U deposits and showings along a ~ 30-km-long NE–SW structural trend. The basement-hosted Kiggavik deposit, comprising three separate mineralized zones (Main, Centre, and East), is located at the northern end of this trend. Multiple styles of U mineralization and alteration were identified at the Kiggavik deposit. Disseminated euhedral uraninite (U1; 1284 ± 53 Ma) has elevated Pb contents up to ~ 14 wt% PbO and is associated with illite and hematite alteration. Vein-style uraninite (U2; 284 ± 19 Ma) forms along fractures, contains lower Pb contents (≤ 3.9 wt% PbO), and is partly altered to Ca–Si-rich (~ 4.5 wt% CaO and ~ 3.3 wt% SiO2) uraninite. Highly altered U2 is associated with galena. Late U minerals (U3) have biogenic textures and are Pb-free, indicating that they formed recently (< 1 Ma). Based on SIMS in situ U–Pb geochronology, the minimum age of uraninite at the Kiggavik deposit is 1284 ± 53 Ma; however, this is likely a reset age associated with the Mackenzie dyke event (~ 1267 Ma). Oxygen and hydrogen stable isotope compositions of illite and muscovite suggest that the Kiggavik deposit has been overprinted by high-latitude surficial fluids derived from snowmelt.

中文翻译：

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加拿大努纳武特 Kiggavik 铀矿床的地球化学和地质年代学

加拿大努纳武特的 Thelon 盆地在年龄、大小和地质方面与萨斯喀彻温省的 U 生产阿萨巴斯卡盆地相似。Kiggavik 项目区紧邻 Thelon 盆地 Aberdeen 子盆地以南，沿约 30 公里长的 NE-SW 构造趋势包含 U 矿床和露头。基底托管的 Kiggavik 矿床由三个独立的矿化带（主要、中心和东部）组成，位于这一趋势的北端。在 Kiggavik 矿床中发现了多种类型的 U 矿化和蚀变。播散自形铀矿 (U1; 1284 ± 53 Ma) 的 Pb 含量高达 ~ 14 wt% PbO，并与伊利石和赤铁矿蚀变有关。脉状铀矿 (U2; 284 ± 19 Ma) 沿裂缝形成，含有较低的 Pb 含量（≤ 3.9 wt% PbO），部分转变为富含 Ca-Si（~ 4. 5 wt% CaO 和 ~ 3.3 wt% SiO2) 铀矿。高度改变的 U2 与方铅矿有关。晚 U 矿物 (U3) 具有生物结构且不含铅，表明它们是最近形成的 (< 1 Ma)。基于SIMS原位U-Pb年代学，Kiggavik矿床铀矿的最小年龄为1284±53Ma；然而，这可能是与 Mackenzie dyke 事件（~1267 Ma）相关的重置年龄。伊利石和白云母的氧和氢稳定同位素组成表明 Kiggavik 矿床已被来自融雪的高纬度地表流体覆盖。Kiggavik 矿床铀矿的最小年龄为 1284±53 Ma；然而，这可能是与 Mackenzie dyke 事件（~1267 Ma）相关的重置年龄。伊利石和白云母的氧和氢稳定同位素组成表明 Kiggavik 矿床已被来自融雪的高纬度地表流体覆盖。Kiggavik 矿床铀矿的最小年龄为 1284±53 Ma；然而，这可能是与 Mackenzie dyke 事件（~1267 Ma）相关的重置年龄。伊利石和白云母的氧和氢稳定同位素组成表明 Kiggavik 矿床已被来自融雪的高纬度地表流体覆盖。