This project aims at reconstructing the architecture of the world class Siguiri orogenic gold district through time and improving the understanding of the geological framework of the Paleoproterozoic Siguiri Basin (Guinea, West Africa).
Gold usually requires a reconcentration factor of up to 30,000 times from its clarke value to be considered as an economical commodity, implying processes capable of strongly concentrating this precious metal. Tightly related to hydrothermalism, those reconcentration processes can transport dissolved gold across great distances using low permeability structures like fractures or falts: this is where this project starts.
Using structural data collected on the field and computer assisted modeling, this research mainly aims to characterise the geological structure of Siguiri gold mine through time and identify the driving structures of the gold bearing fluid(s).
The other aspect of the project focus on how the mineralization formed, e.g. what processes precipitate gold in Siguiri, how many fluids, what was their composition and did they interact between each other, where and what is the source of gold in Siguiri.
The complementarity of those two aspects arises when one starts looking at what structures were present at the time of the mineralization, in the past, to pin-point, today, the next target.
Importance of research
- Structure and mineralization: Siguiri is one of the many gold deposits hosted within the Birimian sediments of the West African Craton but is still not understood in terms of structure and mineralization processes. Hence, this project will focus on understanding why the Siguiri gold deposit is sitting in that particular location.
- From mine scale to Craton scale: The tectonic evolution of the Siguiri Basin and of the West African Craton itself is still a subject of debate. As part of the WAXI project (West African exploration Initiative), one other important aims of this project is to increase the knowledge on that evolution from the data collected in the mine and its vicinity.
- Exploration in Paleoproterozoic terrains: Siguiri is the only large (> 15t in reserve) gold deposit hosted in the Siguiri Basin, which is one of the biggest sedimentary basins in the entire West African Craton. This research will hence focus on an area fairly unknown but with a high prospectivity potential and substantially profitable as gold price keeps increasing when its production has never stopped decreasing since 2005.