Nabarlek
Northern Territory, western Arnhem Land (Alligator Rivers), Australia
UraniumU
- Type
- Basement-hosted Proterozoic unconformity uranium (IAEA class 7.2)
Uranium ore sample from the Queen's University collection analysed by Voinot et al. (2024) for U, Mo and Tl; ε205Tl and δ238U decrease together in metamorphic and unconformity deposits (U reduction and Tl redox change), whereas δ97Mo is strongly modified by late remobilisation. Australian unconformity deposit (age of 1437 Ma used); δ238U at -0.14 ‰, δ234U at equilibrium and δ97Mo of +0.9 ‰; Tl not measured. Indicative coordinates. Uvarova et al. (2014): δ238U (normalisation offset by about +0.60 ‰) and δ234U of samples from the Queen's University collection (Table 2).
δ238U in ‰ (per mil) Values of the same system
Standard : NBL CRM 112-A
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −0.14 ‰ | 1 | uranium ore Single analysis; per-sample uncertainty not published; sample NA1-40.5; IAEA class 7.2 Basement Hosted (Proterozoic unconformity); average age used 1437 Ma; 53.5 % U, 0.01 µg/g Tl, 0.1 µg/g Mo; row duplicated in Table S1, counted once. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … | |
| 0.28 ± 0.1 ‰ | 1 | uraninite Single analysis; ± 0.10 ‰ (2 SD, reproducibility); sample NA4-40.5, Nabarlek; bracketing-only δ238U at +0.36; 238U/235U of 137.875; about -0.32 ‰ after removing the 0.60 ‰ offset specific to this study. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| 0.6 ± 0.1 ‰ | 1 | uraninite Single analysis; ± 0.10 ‰ (2 SD, reproducibility); sample NA88-29.0, Nabarlek; bracketing-only δ238U at +0.57; 238U/235U of 137.92; about 0.00 ‰ after removing the 0.60 ‰ offset specific to this study. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| 0.43 ± 0.1 ‰ | 1 | uraninite Single analysis; ± 0.10 ‰ (2 SD, reproducibility); sample NA1-40.5, Nabarlek; bracketing-only δ238U at +0.43; 238U/235U of 137.896; about -0.17 ‰ after removing the 0.60 ‰ offset specific to this study; same sample as Voinot et al. (2024), published at -0.14 ‰. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| 0.45 ± 0.1 ‰ | 1 | uraninite Single analysis; ± 0.10 ‰ (2 SD, reproducibility); sample NA39-13.8, Nabarlek; bracketing-only δ238U at +0.51; 238U/235U of 137.898; about -0.15 ‰ after removing the 0.60 ‰ offset specific to this study. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… |
δ234U in ‰ (per mil) Values of the same system
Standard : équilibre séculaire
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −1.24 ‰ | 1 | uranium ore Single analysis; per-sample uncertainty not published; sample NA1-40.5; IAEA class 7.2 Basement Hosted (Proterozoic unconformity); average age used 1437 Ma; 53.5 % U, 0.01 µg/g Tl, 0.1 µg/g Mo; row duplicated in Table S1, counted once. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … | |
| −5 ‰ | 1 | uraninite Single analysis; per-sample uncertainty not published; sample NA4-40.5, Nabarlek. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| −15 ‰ | 1 | uraninite Single analysis; per-sample uncertainty not published; sample NA88-29.0, Nabarlek. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| 1 ‰ | 1 | uraninite Single analysis; per-sample uncertainty not published; sample NA1-40.5, Nabarlek; Voinot et al. (2024) report -1.24 ‰ on the same sample. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| −91 ‰ | 1 | uraninite Single analysis; per-sample uncertainty not published; sample NA39-13.8, Nabarlek; 234U deficit: uranium loss within the last 2.5 Myr. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… |
δ97Mo in ‰ (per mil) Values of the same system
Standard : NIST SRM 3134
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 0.9 ± 0.1 ‰ | 1 | uranium ore Single analysis; ± 0.1 (2 SD); sample NA1-40.5; IAEA class 7.2 Basement Hosted (Proterozoic unconformity); average age used 1437 Ma; 53.5 % U, 0.01 µg/g Tl, 0.1 µg/g Mo; row duplicated in Table S1, counted once. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … |
Deposits of the same type
- Jabiluka Australia
- Ranger Australia
- Rum Jungle Australia
- Mary Kathleen Australia
- Pepegoona West Australia
- Pepegoona Australia
- Pannikan Australia
- Mount Painter Australia
Cite this page
IsoFind Atlas (2026). Nabarlek, isotope signatures. https://www.isofind.tech/isotopes/en/deposits/nabarlek/ (accessed 2026-10-16).
@misc{isofind2026nabarlekisotopesignatures,
title = {Nabarlek, isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/nabarlek/},
note = {Accessed 2026-10-16}
}Updated : 2026-10-16