Otavi Mountain Land (Berg Aukas, Baltika)
Northern Namibia, Grootfontein area, Namibia
Mississippi Valley TypeZn-Pb-V
- Type
- Berg Aukas-type MVT with hydrothermal willemite
MVT sulfides of the Neoproterozoic Otavi Group carbonate platform (Damara orogen), replaced by several generations of mostly hydrothermal willemite, then by supergene phases. Early willemite is heavier than sphalerite, late willemite clearly lighter: Rayleigh distillation of a depleted fluid. Indicative coordinates.
δ66Zn in ‰ (per mil) Values of the same system
Standard : JMC 3-0749L
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −0.06 ‰ | 1 | sphalerite (Baltika mine) One analysis (NAR0427A-1, 2 SD 0.02 ‰), Table 1. | Mondillo et al. (2018), A global assessment of Zn isotope fractionation in secondary Zn m… | |
| 0.08 ± 0.01 ‰ | 0.07 / 0.08 ‰ | 2 | willemite I (Baltika, Berg Aukas) Mean and standard deviation recalculated from 2 samples, Table 1. Directly replaces sphalerite. | Mondillo et al. (2018), A global assessment of Zn isotope fractionation in secondary Zn m… |
| −0.42 ‰ | 1 | willemite II in veins and geodes (Berg Aukas) One analysis (BA2003-13.2, 2 SD 0.07 ‰), Table 1. The discussion quotes a -0.35 ‰ offset from willemite I, the table gives -0.49 ‰. | Mondillo et al. (2018), A global assessment of Zn isotope fractionation in secondary Zn m… |
δ18O in ‰ (per mil) Values of the same system
Standard : V-SMOW
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 10.2 ± 0.5 ‰ | 9.9 / 10.55 ‰ | 2 | Berg Aukas willemite Mean and standard deviation recalculated from 2 specimens, Table 3. Duplicates averaged per specimen before computation. Low-temperature hydrothermal. | Mondillo et al. (2020), New insights into the genesis of willemite (Zn2SiO4) from zinc no… |
Deposits of the same type
- Jabali Yémen
- Jebel Trozza Tunisie
- Sekarna (Saint-Pierre) Tunisie
- Bou Jaber Tunisie
- Slata Fer Tunisie
- Jebel Azreg Tunisie
- Mecella Tunisie
- Bou Grine Tunisie
Cite this page
IsoFind Atlas (2026). Otavi Mountain Land (Berg Aukas, Baltika), isotope signatures. https://www.isofind.tech/isotopes/en/deposits/otavi-mountain-land-berg-aukas-baltika/ (accessed 2026-10-13).
@misc{isofind2026otavimountainlandbergaukasbal,
title = {Otavi Mountain Land (Berg Aukas, Baltika), isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/otavi-mountain-land-berg-aukas-baltika/},
note = {Accessed 2026-10-13}
}Updated : 2026-10-13