Viloco (Araca)
Quimsa Cruz, La Paz department, Bolivia
Other hydrothermalSn-W
- Type
- Batholith-related quartz-cassiterite veins
Magmatic-hydrothermal deposit of the Bolivian tin belt (Eastern Cordillera). Subvertical veins issued from the Oligocene Quimsa Cruz batholith, about 1 Myr after emplacement. Indicative coordinates. Position read on the location map of Hirsh et al. (2026).
δ124Sn in ‰ (per mil) Values of the same system
Standard : NIST SRM 3161a
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 0.77 ± 0.4 ‰ | 0.48 / 1.05 ‰ | 2 | cassiterite Mean and standard deviation recalculated from 2 samples, Table 1. | Hirsh et al. (2026), Province-scale tin and zinc stable isotope fractionation trends in t… |
| 0.15 ± 0.85 ‰ | −0.72 / 1.3 ‰ | 6 | cassiterite Mean and standard deviation recalculated from 6 samples, Table 2. Ore age used by the authors: 24 Ma. Classed as porphyry type by the authors. | Mathur et al. (2025), Global Sn isotope compositions of cassiterite identify the magmatic… |
| 1.39 ± 0.22 ‰ | 1 | cassiterite (crystals) Cassiterite solution from the Araca-Viloco mine (Loayza Province, La Paz) used as an in-house standard: +0.174 ± 0.028 ‰ per mass unit by standard-sample bracketing and +0.186 ± 0.001 ‰ by double spike (Table 2), i.e. about +1.39 and +1.49 ‰ on 124Sn/116Sn. Clearly heavier than the Viloco cassiterites of Mathur et al. (2025) and Hirsh et al. (2026): compare with caution. | Bower, Lundstrom and Hendin (2019), MC-ICP-MS analyses of tin isotopes in Roman-era bronz… |
δ66Zn in ‰ (per mil) Values of the same system
Standard : JMC 3-0749L
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 0.3 ± 0.16 ‰ | 0.19 / 0.42 ‰ | 2 | sphalerite (later than cassiterite) Mean and standard deviation recalculated from 2 samples, Table 1. | Hirsh et al. (2026), Province-scale tin and zinc stable isotope fractionation trends in t… |
Deposits of the same type
Cite this page
IsoFind Atlas (2026). Viloco (Araca), isotope signatures. https://www.isofind.tech/isotopes/en/deposits/viloco-araca/ (accessed 2026-10-13).
@misc{isofind2026vilocoaracaisotopesignatures,
title = {Viloco (Araca), isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/viloco-araca/},
note = {Accessed 2026-10-13}
}Updated : 2026-10-13