Massawa

Kédougou Region (Kédougou-Kéniéba inlier, southeast), Senegal

Orogenic goldAu (Sb)

Type
Birimian orogenic gold

Proven reserves of 2.6 million ounces of gold at 4.17 g/t over a 4 km strike length, in low-grade metasediments and metavolcanics of the Kédougou-Kéniéba inlier (Birimian, about 2.1 Ga). Mineralisation formed in two stages: first disseminated gold-bearing sulfides (arsenopyrite and pyrite, carrying up to 90% of the gold in solid solution), then a quartz-stibnite-tetrahedrite stage with visible gold, separated by a quartz-molybdenite phase. It is mined by Barrick (83.25%) with CSSTAO and the Senegalese state, and processed at the Sabodala plant, 20 km away.

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

Standard : V-CDT

ValueRangenMineral or matrixSource
0 / 4.1 ‰sulfides (arsenopyrite, pyrite, stibnite, all mineralisation stages)
A narrow, slightly positive δ34S range, distinct from neighbouring Loulo in Mali (+6 to +15.5 ‰) and Ashanti in Ghana (median -10 ‰), consistent with a fluid of magmatic origin. The signature is the same for both mineralisation stages, indicating a continuous sulfur source.
Treloar et al. 2015, The Massawa gold deposit Eastern Senegal: an orogenic gold deposit s…

δ18O in ‰ (per mil) Values of the same system

Standard : V-SMOW

ValueRangenMineral or matrixSource
5.5 / 10.9 ‰hydrothermal fluid (calculated water δ18O)
Water δ18O calculated from vein analyses, within the usual range of magmatic fluids (5 to 10 ‰). Clearly more magmatic than Loulo in Mali (dolomite δ18O of +15 to +19 ‰) or Ashanti in Ghana.
Treloar et al. 2015, Geological Society London Special Publications 393

Deposits of the same type

Cite this page

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

@misc{isofind2026massawaisotopesignatures,
  title = {Massawa, isotope signatures},
  author = {{IsoFind Atlas}},
  year = {2026},
  url = {https://www.isofind.tech/isotopes/en/deposits/massawa/},
  note = {Accessed 2026-10-06}
}

Updated : 2026-10-06