Abstract
Sadiola Hill is an ~8 Moz gold deposit located in western Mali within a ca. 2200-2050 Ma tectonic window known as Kédougou-Kénieba inlier (KKI), exposing the Western African craton. The deposit is hosted in a metasedimentary package made up of impure carbonate rocks, wackes, and arenites intruded by three distinct igneous phases. A N-S-trending Sadiola shear zone, related to the regional Senegal-Mali shear zone, and NNE-trending third order fault splays acted as conduits for auriferous hydrothermal fluid flow. The deposit has undergone a complex poly-phase alteration history. Alteration assemblages related to gold mineralization consist of biotite-carbonate-quartz-sulphide. Other assemblages include calc-silicates, chlorite, white mica, scapolite, and tourmaline (Hein and Tshibubudze 2007; Cameron 2010; Masurel et al. 2017). Current research is aimed at characterising alteration at the mineral-scale, as well as assessment of cooling trend(s) and alteration footprint(s) with high-resolution short-wave infrared (SWIR) hyperspectral scanning. In addition to detailed mineralogical classification, changes in fluid chemical parameters are determined with variations in white mica, namely, the position of Al-OH bond in the SWIR range and white mica crystallinity. Furthermore, hydrothermal fluid chemistry is assessed with Fe2+ content in carbonate group minerals. Protolith control on alteration expression is also investigated.
| Original language | English |
|---|---|
| Title of host publication | 15th Biennial Meeting of the Society for Geology Applied to Mineral Deposits |
| Subtitle of host publication | Life with ore deposits on Earth |
| Place of Publication | Glasgow |
| Publisher | University of Glasgow |
| Chapter | New Techniques for Ore Discovery |
| Pages | 1325 |
| Number of pages | 1328 |
| Volume | 3 |
| Edition | 15 |
| ISBN (Print) | 9780852619643 |
| Publication status | Published - 27 Aug 2019 |
Keywords
- Hyperspectral imaging
- Gold deposit
- Sadiola Hill
- ITC-GOLD