Bald Hill
Annidale Belt, southern New Brunswick, Canada
Other hydrothermalSb-Au (Cu, Ag)
- Type
- Stibnite-gold veins in volcano-sedimentary rocks
Annidale Group (late Cambrian to Tremadocian, 497 to 481 Ma), Penobscot back-arc between Ganderia and Avalonia, metamorphosed at greenschist facies; auriferous quartz-carbonate veins with chlorite-sericite-fuchsite haloes, ascribed to the Penobscot orogeny and the Stewarton Gabbro (479 ± 2 Ma) according to the authors. NW-trending fault system in mafic volcanics, black shale, siltstone, quartz sandstone and felsic tuff of the Carpenter Brook Formation and the Bald Hill rhyolite dome complex. Early pyrite and arsenopyrite with gold, later stibnite controlled by NW faults cutting Devonian units; resource estimate of 725,000 to 1,000,000 t at 4.11-5.32 % Sb, grab samples up to 3.01 g/t Au. 40Ar-39Ar muscovite plateau age of 422.8 ± 5.6 Ma (late Salinic orogeny), read as a younger system or as resetting by the antimony event. δ34S close to 0 ‰: mantle sulphur or sulphur leached from magmatic rocks. Coordinates from Globex Mining.
δ18O in ‰ (per mil) Values of the same system
Standard : V-SMOW
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 15.8 ‰ | 1 | auriferous vein quartz Single analysis, within the metamorphic fluid range. | Heidarian et al. (2025), Mineralogy, geochronology, and stable isotope geochemistry of go… |
δ34S in ‰ (per mil) Values of the same system
Standard : V-CDT
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −0.7 ‰ | 1 | vein sphalerite Single analysis; mantle sulphur or sulphur leached from magmatic rocks, possibly devolatilisation of basalts. | Heidarian et al. (2025), Mineralogy, geochronology, and stable isotope geochemistry of go… | |
| −0.4 ‰ | 1 | vein stibnite Single analysis. | Heidarian et al. (2025), Mineralogy, geochronology, and stable isotope geochemistry of go… | |
| 1.9 ‰ | 0.7 / 2.8 ‰ | 8 | auriferous veins (whole-rock powders) Value taken from Gray (2019): mean and range over 8 samples, magmatic origin with a mantle signature. | Heidarian et al. (2025), Mineralogy, geochronology, and stable isotope geochemistry of go… |
206Pb/204Pb isotope ratio, no unit Values of the same system
Standard : Non précisé dans la publication
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 18.33 / 18.59 | 5 | mineralised veins (whole rock) Value taken from Gray (2019): range over 5 samples. | Heidarian et al. (2025), Mineralogy, geochronology, and stable isotope geochemistry of go… |
207Pb/204Pb isotope ratio, no unit Values of the same system
Standard : Non précisé dans la publication
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 15.65 / 15.66 | 5 | mineralised veins (whole rock) Value taken from Gray (2019): range over 5 samples. | Heidarian et al. (2025), Mineralogy, geochronology, and stable isotope geochemistry of go… |
208Pb/204Pb isotope ratio, no unit Values of the same system
Standard : Non précisé dans la publication
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 38.26 / 38.62 | 5 | mineralised veins (whole rock) Value taken from Gray (2019): range over 5 samples. | Heidarian et al. (2025), Mineralogy, geochronology, and stable isotope geochemistry of go… |
Deposits of the same type
- Norway (Maine) United States
- Cobalt district Canada
- Tungsten Queen United States
- Irish Creek United States
- Keweenaw native silver district United States
- Black Hills tin belt (South Dakota) United States
- Terlingua United States
- Mike (Carlin Trend) United States
Cite this page
IsoFind Atlas (2026). Bald Hill, isotope signatures. https://www.isofind.tech/isotopes/en/deposits/bald-hill/ (accessed 2026-10-14).
@misc{isofind2026baldhillisotopesignatures,
title = {Bald Hill, isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/bald-hill/},
note = {Accessed 2026-10-14}
}Updated : 2026-10-14