Llallagua

Potosí Department (south-central Bolivian tin belt), Bolivia

PorphyriesSn (Bi, W)

Type
Sn porphyry associated with the Salvadora stock

The largest tin deposit in Bolivia, 80 km southeast of Oruro. Mineralisation is confined to the Salvadora stock, about 1,700 by 1,000 m. Cassiterite veins formed at high temperature (initially 400 to 500 °C) and then under mesothermal conditions.

δ34S in ‰ (per mil) Values of the same system

Standard : V-CDT

ValueRangenMineral or matrixSource
−10.1 ‰fine-grained supergene alunite
A negative signature typical of supergene alteration (oxidation then reprecipitation). At Llallagua, hypogene mineralisation dates from the late Oligocene or early Miocene (19.6 ± 1.0 Ma); the supergene is younger. Central value from a study focused mainly on K-Ar geochronology.
Sugaki et al. K-Ar age determinations of vein- and rock-forming minerals from tin-polymet… (2000)

δ124Sn in ‰ (per mil) Values of the same system

Standard : NIST SRM 3161a

ValueRangenMineral or matrixSource
1.5 ± 0.2 ‰cassiterite (Andean tin belt)
Mean value for the Bolivian tin belt in the Mathur (2024) compilation. Llallagua being the country's largest tin deposit, assigning it this value is an approximation: it represents the whole province. The signature is lighter than in Cornwall, South Dakota and Cínovec-Krupka, attributed to different hydrothermal conditions (lower temperature or a redox process specific to the Bolivian belt).
Mathur et al. 2024, Sn-Isotope Fractionation as a Record of Hydrothermal Redox Reactions

Deposits of the same type

Cite this page

IsoFind Atlas (2026). Llallagua, isotope signatures. https://www.isofind.tech/isotopes/en/deposits/llallagua/ (accessed 2026-10-06).

@misc{isofind2026llallaguaisotopesignatures,
  title = {Llallagua, isotope signatures},
  author = {{IsoFind Atlas}},
  year = {2026},
  url = {https://www.isofind.tech/isotopes/en/deposits/llallagua/},
  note = {Accessed 2026-10-06}
}

Updated : 2026-10-06