In 2017 and 2018, Geovale carried out a detailed assessment of alluvial gold in River thalwegs for a Gabonese miner. Free gold bearing gravel beds and soils are mined by locals. These gold bearing river terraces are located in the remote rainforest covered area over a greenstone belt in Central Gabon. Alluvial gold exploration is tricky due to extreme variability of gold grades along the terrace beds. Hence successful mechanical mining is always a challenge, though extensive artisanal activities are always seen. Environmental and community management of a mechanical mining operation next to artisanal activities bring in additional challenges.

Geovale’s Mineral Services lead with a team of exploration geologists and experienced Process E ngineer to carry out a detailed study of the area. The gold bearing terraces were mapped in detail and Geological Resource was established. An appropriate mining and rehabilitation plan were recommended.

The systematic approach included the following:

  • Systematic exploration of the potential gold bearing river terraces and identification of different types of gold bearing alluvial materials.
  • Systematic sampling program of different geological hosts and gold grade analysis using fire assay.
  • Establishing gold grade variations and mapping availability of free gold in the river terraces.
  • Geological Resource estimation of the alluvial gold beds.

Geovale provided detailed exploration project report with recommendation and way forward to carry out detailed processing study. The project was delivered within a timeline of 1 year.