SANGOLA LICENCE - SENEGAL
Location
The Licence area is approximately 471 km² in extent and mostly covers the gold-prospective Kenieba Inlier of Birimian Formation. The licence is located 30 km west of Kedougou (Figure 1), the regional capital city. From Dakar the permit is reached on tarred roads via Tambacounda to Kedougou.
Prospectivity
The area covered by the licence is highly prospective because exploration of the Kenieba Inlier resulted in the discovery of more than 30 million ounces ("Moz") of gold in five major deposits in Mali and Senegal. The Licence contains locations of artisanal gold mining activity (Figure 2) and covers the south-western part of the Main Transcurrent Shear Zone (“MTZ”), a major gold bearing system that yielded the recently discovered 3.4 Moz Massawa gold deposit (Randgold Resources Ltd). The Massawa gold project is presently undergoing a feasibility study and most likely will be the second modern gold mine in Senegal after the first gold was poured at Mineral Deposits Limited’s Sabodala gold mine during March 2009. Further to the north the same gold belt is targeted by Mineral Deposits Limited and Bassari Resources Limited (Figure 3). Both companies have located new mineralisation (Sounkounkou and Sanbarabougou) along this 70 km long gold anomalous belt. The Licence covers the very prospective basalts and andesites (Mako Volcanic Formation) that host the 3 Moz Sabodala deposit, presently the only active gold mine in Senegal. Despite its strategic position the Licence is still largely unexplored.
GoldStone’s Exploration
A desk top study based on remotely sensed data to generate geological and structural maps was completed during November 2010. The results confirmed that the andesites and associated gold-fertile MTZ structure extend from the Massawa gold deposit into the Sangola permit. A detected potassium anomaly over parts of the structure confirmed that this structure served as a conduit for hydrothermal fluids (Figure 4). Potassium anomalies commonly form halos around gold deposits in hydrothermal belts.
A termite mound sampling programme covering most of the 471 km2 permit area in Eastern Senegal was completed during March 2011. A total of 8,150 samples were taken from termite mounds along north-south trending lines to detect any gold mineralisation in the underlying Birimian rocks. In order to gain a better understanding of the hydrothermal processes that resulted in the gold mineralisation, the samples were also analysed for gold pathfinder elements such as silver and arsenic. The analyses of pathfinder elements has been completed for all samples, however the Company has received gold results for only 2,500 of the 8,150 samples. The results for silver and arsenic clearly confirm the location of the gold-fertile MTZ in the permit area (Figure 5). The limited number of gold results received to date indicates that gold mineralisation is present at various locations and in one case is associated with secondary structures (splays) along the margin of the MTZ. A full interpretation of the data will be provided once the gold results have been received for all samples. Follow-up work will include ground geophysical work, infill soil sampling and trenching.
Figure 1: The Sangola permit area lies along the same regional structural corridor (MTZ) that controlled the formation of the Massawa gold deposit (Randgold Resources) and also covers the prospective basalts and andesites of the Mako Group which host the 3 Moz Sabodala gold mine (Mineral Deposits Limited). Exploration in the area depicted on the map resulted in the discovery of more than 30 Moz of gold. The Sangola permit area, however, is largely unexplored and accordingly holds the potential for new significant hydrothermal gold discoveries.
Figure 2: It can be seen that the Sangola permit contains several artisanal gold workings. Future field work will be directed to quantify the gold mineralisation at these locations. The association of the MTZ with numerous gold occurrences (e.g. Sounkounkou, Sanbarabougou and Massawa) clearly demonstrates the prospectivity of this shear system.
Figure 3: The Kenieba Inlier of Birimian Formation is the focus of exploration by several well established gold mining and exploration companies. These include Mineral Deposits Limited (recently acquired by Taranga Gold), Oromin Exploration Limited, Randgold Resources, Iamgold and Bassari Resources. All of these companies have been successful in delineating significant gold mineralisation in this area.
Figure 4: A geological and structural map of the Sangola permit – the results of a desk top study completed for GoldStone during November 2010. It can be seen that the andesites of the gold-fertile MTZ structure (green) extend into the Sangola permit. The potassium anomaly associated with this structure confirms that this structure served as a conduit for hydrothermal fluids.Potassium is considered a pathfinder element for gold in this geological environment.
Figure 5: Anomalous gold concentrations in samples taken from termite mounds shown over the first vertical derivative of magnetic data and topography. The anomalous samples yielded three large and consistent gold anomalies all of which correlate with secondary structures parallel to the MTZ or splays off the MTZ.