Loulo (district de Gara-Yalea)
Kayes (western Mali, Kédougou-Kéniéba inlier), Mali
Orogenic goldAu
- Type
- Birimian orogenic gold
A world-class gold district in the Kédougou-Kéniéba inlier, along the Senegal-Mali shear zone. It includes four main deposits: Gara, Yalea, P-129 and P-64. Gold occurs in quartz veins and tourmalinised hydrothermal breccias hosted in Birimian metasediments (about 2.1 Ga). It is mined by Barrick Gold.
δ34S in ‰ (per mil) Values of the same system
Standard : V-CDT
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 5.8 / 15.5 ‰ | district sulfides (Gara, Yalea and others) Total range of the Loulo district. Malian δ34S matches syngenetic to diagenetic pyrites, unlike Ghana's Ashanti belt, which is much more negative (median about -10 ‰). This contrast distinguishes the two neighbouring Birimian belts. | Lawrence et al. 2013, gold mineralization Loulo district | ||
| 11.5 / 15.5 ‰ | Gara sub-deposit sulfides The Gara sub-deposit, with a clearly higher range than the rest of the district, in tourmalinised metaturbidites with a heterogeneous host. | Lawrence et al. 2013, gold mineralization Loulo district | ||
| 6 / 12.9 ‰ | sulfides (three orebodies: Loulo 0, P64 and others) A pioneering isotopic study of three orebodies. Groups differ by location, but pre- and post-schistosity sulfides are indistinguishable. This indicates two 18O-enriched hydrothermal systems active at different times. | Fouillac et al. 1993, A carbon oxygen hydrogen and sulfur isotopic study of the gold mine… |
δ18O in ‰ (per mil) Values of the same system
Standard : V-SMOW
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 15.1 / 19.5 ‰ | hydrothermal dolomites (Loulo 0, P64) Dolomites in veins, veinlets or disseminated, deposited by hydrothermal fluids. A sedimentary hanging-wall dolomite reaches +22.2 ‰, outside the hydrothermal range. | Fouillac et al. 1993, Chemical Geology |
δ13C in ‰ (per mil) Values of the same system
Standard : V-PDB
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −13.5 / −2 ‰ | hydrothermal dolomites The first carbon entry in the database. The δ13C range reflects a mixture of sedimentary, metamorphic and magmatic sources, unlike the sedimentary hanging-wall dolomite (+3.8 ‰). A classic signature of orogenic gold fluids. | Fouillac et al. 1993, Chemical Geology |
Deposits of the same type
- Gounkoto Mali
- Massawa Senegal
- Ashanti (Obuasi) Ghana
- Muruntau Uzbekistan
- Kalgoorlie (Golden Mile) Australia
- Victorian Goldfields Australia
Cite this page
IsoFind Atlas (2026). Loulo (district de Gara-Yalea), isotope signatures. https://www.isofind.tech/isotopes/en/deposits/loulo-district-de-gara-yalea/ (accessed 2026-10-06).
@misc{isofind2026loulodistrictdegarayaleaisoto,
title = {Loulo (district de Gara-Yalea), isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/loulo-district-de-gara-yalea/},
note = {Accessed 2026-10-06}
}Updated : 2026-10-06