Northrim
Northwest Territories, Great Bear Lake, Camsell River sector, Canada
Other hydrothermalAg (Ni, Co, Bi, U)
- Type
- Native silver and Ni-Co arsenide veins (five-element type)
Northrim mine, with the widest spread in lead isotope ratios (prolonged fluid interaction according to the authors). Veins with native silver, Ni-Co arsenides, sulfarsenides, hematite, sulfosalts, native bismuth and sulfides, locally with pitchblende, in volcano-sedimentary roof pendants of the Great Bear batholithic complex (Wopmay orogen, about 1860-1875 Ma); uranium and silver production from 1930 to 1983. Changkakoti et al. (1986): steep, little radiogenic galena lead, highly radiogenic carbonates; multiple and poorly homogenised lead sources, mineralisation age proposed at about 1500 Ma; carbonate Sr from 0.709 to 0.720, above the initial Sr of the Echo Bay volcanics (0.702 ± 0.003). Indicative coordinates: Camsell River property (former Silver Bear, Norex, Northrim and Smallwood mines), position of the Terra mine taken from its Mindat entry (65°36′15″ N, 118°06′55″ W), to within 5 km.
206Pb/204Pb isotope ratio, no unit Values of the same system
Standard : NIST SRM 981
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 15.928 ± 0.024 | 15.905 / 15.978 | 7 | vein galena Mean and standard deviation recalculated from 7 analyses, 15.905 to 15.978 (AC/32/NR 15.978; AC/31/NR 15.935; AC/44/NR 15.905; AC/42/NR 15.918; AC/41/NR 15.927; AC/45/NR 15.912; AC/33/NR 15.922). Composition of the ore fluid at deposition according to the authors. | Changkakoti et al. (1986), Pb and Sr isotope compositions of hydrothermal minerals from t… |
| 16.759 ± 0.083 | 16.7 / 16.818 | 2 | vein chalcopyrite Mean and standard deviation recalculated from 2 analyses, 16.700 to 16.818 (AC/C2/NR 16.818; AC/C1/NR 16.700). Slightly more radiogenic than galena: radiogenic lead added since deposition according to the authors. | Changkakoti et al. (1986), Pb and Sr isotope compositions of hydrothermal minerals from t… |
| 16.99 | 1 | vein carbonates (calcite and dolomite) Single analysis (NR/1, dolomite). Present-day ratios, not corrected for in situ decay of uranium in the carbonates. | Changkakoti et al. (1986), Pb and Sr isotope compositions of hydrothermal minerals from t… |
207Pb/204Pb isotope ratio, no unit Values of the same system
Standard : NIST SRM 981
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 15.375 ± 0.03 | 15.355 / 15.441 | 7 | vein galena Mean and standard deviation recalculated from 7 analyses, 15.355 to 15.441 (AC/32/NR 15.441; AC/31/NR 15.377; AC/44/NR 15.355; AC/42/NR 15.365; AC/41/NR 15.366; AC/45/NR 15.363; AC/33/NR 15.361). Composition of the ore fluid at deposition according to the authors. | Changkakoti et al. (1986), Pb and Sr isotope compositions of hydrothermal minerals from t… |
| 15.494 ± 0.028 | 15.474 / 15.513 | 2 | vein chalcopyrite Mean and standard deviation recalculated from 2 analyses, 15.474 to 15.513 (AC/C2/NR 15.474; AC/C1/NR 15.513). Slightly more radiogenic than galena: radiogenic lead added since deposition according to the authors. | Changkakoti et al. (1986), Pb and Sr isotope compositions of hydrothermal minerals from t… |
| 15.54 | 1 | vein carbonates (calcite and dolomite) Single analysis (NR/1, dolomite). Present-day ratios, not corrected for in situ decay of uranium in the carbonates. | Changkakoti et al. (1986), Pb and Sr isotope compositions of hydrothermal minerals from t… |
208Pb/204Pb isotope ratio, no unit Values of the same system
Standard : NIST SRM 981
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 35.682 ± 0.088 | 35.614 / 35.876 | 7 | vein galena Mean and standard deviation recalculated from 7 analyses, 35.614 to 35.876 (AC/32/NR 35.876; AC/31/NR 35.666; AC/44/NR 35.614; AC/42/NR 35.647; AC/41/NR 35.670; AC/45/NR 35.646; AC/33/NR 35.652). Composition of the ore fluid at deposition according to the authors. | Changkakoti et al. (1986), Pb and Sr isotope compositions of hydrothermal minerals from t… |
| 36.09 ± 0.158 | 35.978 / 36.202 | 2 | vein chalcopyrite Mean and standard deviation recalculated from 2 analyses, 35.978 to 36.202 (AC/C2/NR 35.978; AC/C1/NR 36.202). Slightly more radiogenic than galena: radiogenic lead added since deposition according to the authors. | Changkakoti et al. (1986), Pb and Sr isotope compositions of hydrothermal minerals from t… |
| 36.626 | 1 | vein carbonates (calcite and dolomite) Single analysis (NR/1, dolomite). Present-day ratios, not corrected for in situ decay of uranium in the carbonates. | Changkakoti et al. (1986), Pb and Sr isotope compositions of hydrothermal minerals from t… |
87Sr/86Sr isotope ratio, no unit Values of the same system
Standard : NIST SRM 987
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 0.71083 | 1 | vein dolomite Single analysis (NR/1). Rb (ppm), Sr (ppm), 87Rb/86Sr: NR/1 0.1269, 28.39, 0.0135. Very low Rb/Sr: measured ratios approach those at deposition. | Changkakoti et al. (1986), Pb and Sr isotope compositions of hydrothermal minerals from t… |
Deposits of the same type
- Norex Canada
- Smallwood Canada
- Terra (Silver Bear) Canada
- Contact Lake Canada
- McDermitt United States
- Turquoise Ridge (Getchell trend) United States
- Getchell United States
- Mike (Carlin Trend) United States
Cite this page
IsoFind Atlas (2026). Northrim, isotope signatures. https://www.isofind.tech/isotopes/en/deposits/northrim/ (accessed 2026-10-22).
@misc{isofind2026northrimisotopesignatures,
title = {Northrim, isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/northrim/},
note = {Accessed 2026-10-22}
}Updated : 2026-10-22