Webster-Addie (Democrat)
Buncombe County, North Carolina, United States
OtherNi (garniérite, historique)
- Type
- Nickel laterite on ultramafic rock (garnierite saprolite)
Weathering profile of the Webster-Addie ultramafic complex (Bish, 1977): dunite and talc-rich altered dunite, saprolite with veins of hydrous Ni-Mg silicates (garnierite), yellow nontronite laterite. Garnierites from other laterites in the same study: Riddle (Oregon) +0.55 ‰, Indonesia +0.76 and +0.61 ‰, Madagascar +0.90 ‰, unknown provenance +0.36 ‰. Indicative coordinates.
δ60Ni in ‰ (per mil) Values of the same system
Standard : NIST SRM 986
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 0.13 ± 0.1 ‰ | 0.06 / 0.2 ‰ | 2 | dunite and altered dunite (protolith) Mean and standard deviation recalculated from 2 analyses, within the mantle range. | Spivak-Birndorf et al. (2018), Nickel isotope fractionation during continental weathering… |
| 0.51 ± 0.22 ‰ | 0.26 / 0.86 ‰ | 7 | garnierite (hydrous Ni-Mg silicates from saprolite veins) Mean and standard deviation recalculated from 7 analyses, heavier than the parent rock: heavy nickel, carried down by percolating waters, is fixed in the veins. | Spivak-Birndorf et al. (2018), Nickel isotope fractionation during continental weathering… |
| −0.12 ‰ | 1 | yellow nontronite laterite Single analysis, the lightest nickel of the profile; the abstract gives -0.21 ‰, the table and text -0.12 ‰ (kept). | Spivak-Birndorf et al. (2018), Nickel isotope fractionation during continental weathering… | |
| 0.24 ± 0.16 ‰ | 0.13 / 0.35 ‰ | 2 | lateritic mixtures (quartz, smectite, serpentine, goethite) Mean and standard deviation recalculated from 2 analyses, samples Mix-1 and Mix-2. | Spivak-Birndorf et al. (2018), Nickel isotope fractionation during continental weathering… |
Deposits of the same type
- Ahles mine United States
- Inshow prospect United States
- Stinson mine United States
- Davis mine United States
- Shaw mine United States
- Howell Farm mine United States
- Sulphur Hill mine United States
- Roseville mine United States
Cite this page
IsoFind Atlas (2026). Webster-Addie (Democrat), isotope signatures. https://www.isofind.tech/isotopes/en/deposits/webster-addie-democrat/ (accessed 2026-10-13).
@misc{isofind2026websteraddiedemocratisotopesi,
title = {Webster-Addie (Democrat), isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/webster-addie-democrat/},
note = {Accessed 2026-10-13}
}Updated : 2026-10-13