Orrefjell
Norway (location not given), Norway
UraniumU
- Type
- Uraninite-bearing pegmatite or alaskite (IAEA class 1.1)
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. Pristine uraninite, average mineralisation age of 1755 Ma; ε205Tl of -8.0. Coordinates not published.
δ238U in ‰ (per mil) Values of the same system
Standard : NBL CRM 112-A
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −0.52 ‰ | 1 | pristine uraninite Single analysis; per-sample uncertainty not published; sample E2342 (Uvarova et al., 2014, place it at Halvorsrød (Norway, bröggerite)); IAEA class 1.1. Anatectic: Pegmatite - alaskite (intrusive); average age used 1755 Ma; 66.55 % U, 0.9 µg/g Mo. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … |
δ234U in ‰ (per mil) Values of the same system
Standard : équilibre séculaire
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −2.3 ‰ | 1 | pristine uraninite Single analysis; per-sample uncertainty not published; sample E2342 (Uvarova et al., 2014, place it at Halvorsrød (Norway, bröggerite)); IAEA class 1.1. Anatectic: Pegmatite - alaskite (intrusive); average age used 1755 Ma; 66.55 % U, 0.9 µg/g Mo. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … |
ε205Tl in ε units (parts per 10,000) Values of the same system
Standard : NIST SRM 997
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −8 ± 1 ε | 1 | pristine uraninite Single analysis; ± 1.0 (2 SD); sample E2342 (Uvarova et al., 2014, place it at Halvorsrød (Norway, bröggerite)); IAEA class 1.1. Anatectic: Pegmatite - alaskite (intrusive); average age used 1755 Ma; 66.55 % U, 0.9 µg/g Mo. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … |
δ97Mo in ‰ (per mil) Values of the same system
Standard : NIST SRM 3134
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 4 ± 0.43 ‰ | 1 | pristine uraninite Single analysis; ± 0.43 (2 SD); sample E2342 (Uvarova et al., 2014, place it at Halvorsrød (Norway, bröggerite)); IAEA class 1.1. Anatectic: Pegmatite - alaskite (intrusive); average age used 1755 Ma; 66.55 % U, 0.9 µg/g Mo. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … |
Deposits of the same type
- Athabasca basin (unconformity uranium province) Canada
- Shea Creek (Athabasca) Canada
- Tim Mersoï basin (Arlit, Akouta, Imouraren) Niger
- Inkai (Chu-Sarysu basin) Kazakhstan
- Tulukuevskoye Russia
- Ty Gallen France
- Rophin France
- Key Lake (Deilmann and Gaertner) Canada
Cite this page
IsoFind Atlas (2026). Orrefjell, isotope signatures. https://www.isofind.tech/isotopes/en/deposits/orrefjell/ (accessed 2026-10-16).
@misc{isofind2026orrefjellisotopesignatures,
title = {Orrefjell, isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/orrefjell/},
note = {Accessed 2026-10-16}
}Updated : 2026-10-16