Lengenbach (Binn Valley)
Valais, Binn Valley (Monte Leone nappe), Switzerland
OtherPb-As-Tl-Zn
- Type
- Pb-As-Tl-Zn sulfosalt deposit in metamorphosed Triassic dolomites, formed from a sulfide melt
Stratiform layers dominated by pyrite (up to 80 vol%), with sphalerite and galena, in Triassic dolomites of the Lengenbach stratum (about 240 m), between basement gneisses of the Monte Leone nappe and the Bündnerschiefer; reduced, As(III) and intermediate redox zones, and fissures with over 50 sulfosalts. Type locality of 31 minerals, 16 known only here (jordanite, hatchite, edenharterite, sartorite, hutchinsonite...). Sulfide melt formed at the Alpine metamorphic peak (500 to 520 °C, 6.5 to 7.5 kbar, 28 Ma), then fractional crystallisation enriching the residual melt in As and Tl. ε205Tl from -4.1 to +1.9 within the deposit alone: jordanite lightest, other sulfosalts from +0.6 to +1.9; the heavy, As-poor fahlores would come from hydrothermal fluids. MVT-type precursor possibly enriched in Tl, Cu and As by marine Fe-Mn oxides (Hettmann et al., 2014). Lengenbach quarry coordinates after Wikipedia.
ε205Tl in ε units (parts per 10,000) Values of the same system
Standard : NIST SRM 997
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −2.8 ± 1.84 ε | −4.1 / −1.5 ε | 2 | jordanite Mean and standard deviation recalculated from 2 analyses, Bin 1 (2 measurements, lightest of the study) and Bin 3 (2); massive jordanite of the intermediate redox zone, lowest Tl/As ratio. | Hettmann et al. (2014), Thallium geochemistry in the metamorphic Lengenbach sulfide depos… |
| 1.05 ± 0.07 ε | 1 / 1.1 ε | 2 | fahlore (tennantite) Mean and standard deviation recalculated from 2 analyses, Bin 2 (2 measurements) and Bin 5 (1); heavy and As-poor, off the Tl/As trend of the sulfosalts, ascribed to hydrothermal fluids. | Hettmann et al. (2014), Thallium geochemistry in the metamorphic Lengenbach sulfide depos… |
| 0.6 ± 0.5 ε | 1 | hatchite Single analysis; Bin 4; highest molar Tl/As ratio (0.56). | Hettmann et al. (2014), Thallium geochemistry in the metamorphic Lengenbach sulfide depos… | |
| 1.9 ± 0.5 ε | 1 | edenharterite Single analysis; Bin 6, measured twice on the same solution; heaviest value of the study. | Hettmann et al. (2014), Thallium geochemistry in the metamorphic Lengenbach sulfide depos… | |
| −1.35 ± 1.2 ε | −2.2 / −0.5 ε | 2 | sartorite Mean and standard deviation recalculated from 2 analyses, Bin 9 and Bin 12 (2 measurements each); euhedral vug crystals of the As(III) zone. | Hettmann et al. (2014), Thallium geochemistry in the metamorphic Lengenbach sulfide depos… |
| 1.1 ± 0.5 ε | 1 | orpiment Single analysis; Bin 11; fissure coatings. | Hettmann et al. (2014), Thallium geochemistry in the metamorphic Lengenbach sulfide depos… | |
| −0.3 ± 0.5 ε | 1 | sulfide melt inclusions in quartz Single analysis; Bin 13, measured twice on the same solution; inclusions described by Hofmann (1994). | Hettmann et al. (2014), Thallium geochemistry in the metamorphic Lengenbach sulfide depos… |
Deposits of the same type
- Stelvio Italy
- Oris Italy
- Lahn-Dill ores (Grube Fortuna, Wetzlar) Germany
- Largentière France
- Eyller Bruch bog iron ore Germany
- Klingenthal-Kraslice Germany
- Mansfeld Kupferschiefer (Eisleben) Germany
- Benasque Pass mines (Mina Peak) Spain
Cite this page
IsoFind Atlas (2026). Lengenbach (Binn Valley), isotope signatures. https://www.isofind.tech/isotopes/en/deposits/lengenbach-vallee-de-binn/ (accessed 2026-10-15).
@misc{isofind2026lengenbachbinnvalleyisotopesi,
title = {Lengenbach (Binn Valley), isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/lengenbach-vallee-de-binn/},
note = {Accessed 2026-10-15}
}Updated : 2026-10-15