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Yatela Gold Mine, Mali

Geology & Mineralization


The Yatela deposit is located within the northern, Malian portion of the Kenieba - Kedougou window.  A full description of the regional geology can be found under the Sadiola Gold Mine Geology & Mineralization section of this website.


Gold and disseminated pyrite with associated albite, sericite and dolomite alteration occurs along a faulted contact between a carbonate sequence and a diorite, all unconformably overlain by Upper Proterozoic Seroukoto sandstones. Economic mineralization occurs in an unconsolidated ferruginous, sandy, locally clayey unit that lines the bottom of deep troughs (max 220 m) developed over the carbonates.  The ore zone is overlain by a thick unit of angular blocks of Seroukoto sandstone and shale.  This is covered by a fine sand unit and with interbedded layers of pisolithic gravel and laterite rubble.  The final fill consists of stacked subhorizontal layers of pisolithic gravel grading into fine sands.  The geometry of the lateritic layering indicates that deposition was concomitant with the deepening of the trough as deeper pisolithic layers show gradually increased sagging with depth.  This is thought to result from karstic dissolution of mineralized carbonate and simultaneous infill of the depression. The ferruginous basal ore corresponds to the gold-enriched dissolution residue of the mineralized carbonate (Hanssen et al., 2004).