Perkoa
Sanguié Province, Birimian Boromo belt, Burkina Faso
Volcanogenic massive sulfidesZn (Pb, Ag)
- Type
- Zinc-rich volcanic-hosted massive sulfide (VHMS)
Stratiform zinc deposit in Palaeoproterozoic (Birimian) volcano-sedimentary rocks, capped by a gossan of hematite, goethite, clays and alunite-group sulfates. Weathering depletes the gossan in heavy copper isotopes (about -2.4 ‰) and slightly in zinc (about -0.7 ‰), while lead keeps the ore signature, distinct from the regional barren ferruginous crust. Indicative coordinates.
δ65Cu in ‰ (per mil) Values of the same system
Standard : NIST SRM 976
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 2.04 ± 0.13 ‰ | 1.91 / 2.17 ‰ | 3 | massive sulfide ore Mean and standard deviation recalculated from 3 samples, Table 2. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
| 0.94 ± 0.62 ‰ | 0.21 / 1.73 ‰ | 6 | disseminated sulfide ore Mean and standard deviation recalculated from 6 samples, Table 2. Lead, more variable than in massive ore, mixes ore and host-rock lead. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
| −0.32 ± 0.27 ‰ | −0.58 / −0.02 ‰ | 4 | gossan Mean and standard deviation recalculated from 4 samples, Table 2. Copper depleted in 65Cu by about 2.4 ‰ relative to massive ore; lead identical to massive ore. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
| −0.6 ± 0.1 ‰ | −0.69 / −0.49 ‰ | 3 | bleached and argillised gossan envelope Mean and standard deviation recalculated from 3 samples, Table 2. The text places gossan and envelope zinc between -0.88 and +0.34 ‰. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
δ66Zn in ‰ (per mil) Values of the same system
Standard : NIST SRM 683
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 0.33 ± 0.03 ‰ | 0.3 / 0.36 ‰ | 3 | massive sulfide ore Mean and standard deviation recalculated from 3 samples, Table 2. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
| 0.41 ± 0.15 ‰ | 0.17 / 0.63 ‰ | 6 | disseminated sulfide ore Mean and standard deviation recalculated from 6 samples, Table 2. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
| −0.4 ± 0.34 ‰ | −0.88 / −0.099 ‰ | 4 | gossan Mean and standard deviation recalculated from 4 samples, Table 2. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
| 0.05 ± 0.44 ‰ | −0.46 / 0.34 ‰ | 3 | bleached and argillised gossan envelope Mean and standard deviation recalculated from 3 samples, Table 2. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
206Pb/207Pb isotope ratio, no unit Values of the same system
Standard : NIST SRM 981
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 0.98 ± 0.006 | 0.976 / 0.987 | 3 | massive sulfide ore Mean and standard deviation recalculated from 3 samples, Table 1. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
| 1.013 ± 0.029 | 0.978 / 1.052 | 6 | disseminated sulfide ore Mean and standard deviation recalculated from 6 samples, Table 1. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
| 0.98 ± 0.002 | 0.979 / 0.983 | 4 | gossan Mean and standard deviation recalculated from 4 samples, Table 1. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
| 0.994 ± 0.03 | 0.978 / 1.039 | 4 | bleached and argillised gossan envelope Mean and standard deviation recalculated from 4 samples, Table 1. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
208Pb/206Pb isotope ratio, no unit Values of the same system
Standard : NIST SRM 981
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 2.337 ± 0.006 | 2.332 / 2.344 | 3 | massive sulfide ore Mean and standard deviation recalculated from 3 samples, Table 1. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
| 2.294 ± 0.038 | 2.264 / 2.345 | 6 | disseminated sulfide ore Mean and standard deviation recalculated from 6 samples, Table 1. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
| 2.341 ± 0.004 | 2.336 / 2.346 | 4 | gossan Mean and standard deviation recalculated from 4 samples, Table 1. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
| 2.318 ± 0.045 | 2.252 / 2.346 | 4 | bleached and argillised gossan envelope Mean and standard deviation recalculated from 4 samples, Table 1. | Kříbek et al. (2016), Geochemistry, mineralogy, and isotope composition of Pb, Zn, and Cu… |
Deposits of the same type
- Aznalcóllar Spain
- Los Frailes Spain
- Sotiel Spain
- Tharsis Spain
- Rio Tinto Spain
- Rio Tinto Spain
- Peña de Hierro Spain
- Iberian Pyrite Belt (representative example) Spain/Portugal
Cite this page
IsoFind Atlas (2026). Perkoa, isotope signatures. https://www.isofind.tech/isotopes/en/deposits/perkoa/ (accessed 2026-10-13).
@misc{isofind2026perkoaisotopesignatures,
title = {Perkoa, isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/perkoa/},
note = {Accessed 2026-10-13}
}Updated : 2026-10-13