Located in Eastern Senegal and covering 53.2km2 over the gold-bearing Kédougou-Kéniéba Inlier, Diamba Sud is the Company’s flagship project. Consisting of two blocks (DS1 & DS2) joined by a narrow strip, the Diamba Sud Project is located to the west of the regionally significant Senegal-Mali Shear Zone (“SMSZ”).
World-class gold deposits and mines including; Loulo (Barrick), Gounkoto (Barrick), Sadiola (IAMGold/Anglo Gold), Yatela (IAMGold/Anglogold) and Fekola (B2Gold) are all adjacent or proximal to the SMSZ on parallel structures or splays. Critically, Diamba Sud is proximal to the SMSZ, 7km due west of Barrick’s Gounkoto mine in Mali on the underexplored western side, in Senegal.
Proximity to world class deposits, combined with the minimal historical exploration, makes Diamba Sud highly prospective for orogenic gold mineralisation. This prospectivity has been progressively enhanced by extensive gold anomalies identified by auger drilling and subsequent drilling encountering; a) high-grade gold associated with, b) strong alteration in, c) sedimentary host rocks, and, d) dominant control parallel to the structural splay suggested by the Western Splay. These four features are key characteristics at the world class Fekola and Gounkoto gold mines.
The Diamba Sud exploration permit is located within the highly prospective Kédougou-Kéniéba Inlier which forms part of the Paleoproterozoic age Birimian Terrane of the West African Craton. Over 35 million ounces of gold has been discovered over the last 23 years within this inlier. The permit lies within the felsic volcanics and sediments of the Faleme Series, bound by the sediment-dominated Diale-Dalema Supergroup to the west and the SMSZ and the Kofi Series to the east.
The Faleme and Diale-Dalema supracrustal sequences are intruded by a series of variably deformed granitoid intrusions. Lithologies in the region are affected mainly by lower green schist grade metamorphism.
Exploration programs undertaken by the Company have successfully defined two significant gold discoveries at Diamba Sud – Area A and Area D, along with a host of highly prospective additional targets.
Area A: Geological similarities to Gounkoto and Fekola
Exploration results at Area A have confirmed a high-grade gold discovery, including confirmation of a northwest-southeast dilational structure interpreted as the principal host of the high-grade mineralisation, as well as the presence of an additional potentially significant northeast-southwest structural trend. The high-grade mineralisation appears to be associated with the intersection of the two structural trends.
The interpreted host structures and associated gold mineralisation remain open along strike and are priority targets for follow-up drilling.
The gold mineralisation is principally structurally hosted, with a second style of mineralisation within altered sedimentary breccias. Both the structurally hosted and the lithological hosted pyrite mineralisation are associated with intense albite-carbonate-hematite alteration, typical of the assemblages found associated with other Tier 1 gold operations along the SMSZ.
These characteristics provide strong indications that Area A is part of, or proximal to, a larger hydrothermal system, with marked similarities to other large systems and tier 1 operations on the SMSZ.
Area D: A new high-grade discovery
Exploration at Area D has intersected high-grade intervals of up to 67.80 g/t gold within broad continuous zones of mineralisation that is interpretated to be controlled by northwest-southeast striking host structures. Significant results include;
- 48m at 6.70 g/t gold from 24m, including
- 10m at 25.14 g/t gold from 62m
- 55m at 4.27 gold from 16m
- 38m at 4.63 g/t gold from 8m, including
- 18m at 7.04 g/t gold from 28m, including
- 4m at 18.30 g/t gold from 30m
- 36m at 2.93 g/t gold from 6m, including
- 10m at 6.13 g/t gold from 16m
Mineralisation is heavily oxidised within a fine grained saprolitic sandstone unit. Weathering is distinctly deeper at Area D, suggesting faulting. Drilling to date is shallow so potential depth extensions remain untested and a focus for next drilling (Figure 6). Induced polarisation (IP) imaging shows a significant structure trending northwest from Area D, with the potential to be the faulted offset of Area A, which is located approximately 0.5km to the east. The IP and geology suggest that a northeast-southwest trending fault traces through both Area D and Area A, in both cases truncating the mineralisation and northwest trending host structure. These northeast-southwest trending faults are identified as late regional features.
The potential continuation of the northwest hosting structure at Area D provides the potential for the discovery of a very large system at Diamba Sud, with significant strike length to the northwest on Chesser’s property that will be explored from H2 2020.
Western Splay Area Targets
A gradient array induced polarization (GAIP) geophysical survey undertaken over the Western Splay area of Diamba Sud indicated the presence of a major northwest-trending splay structure extending from the SMSZ to the west of the Company’s previous drilling.
Given the spatial association of all major gold deposits along the SMSZ either on or adjacent to splays extending from the SMSZ (e.g. Boto, Fekola, Gounkoto, Loulo, Yatela and Sadiola), this structure represents a high priority target for future exploration activities.
Results from drilling at the initial targets at the Western Splay area successfully intersected a mineralised structure approximately 5km to the southwest of the Area A discovery and immediately west of the main Western Splay structure. The drilling confirmed a mineralised trend over ~300m, which is believed to extend by at least a further ~200m to the artisanal workings located along strike.
This structure and the broader Western Splay area are considered highly prospective with multiple targets expected to be tested in future drilling.