Sudan – Orca Gold president and CEO Hugh Stuart notes that water is a major factor in the development of a gold mine, particularly in a desert environment – such as the Block 14 gold project.
The successful expansion of the Area 5 aquifer at its Block 14 gold project in the Republic of the Sudan means that the Galat Sufar South (GSS) deposit and supporting processing plant can now be developed to its full design potential.
The Area 5 aquifer, located 85 km from the main GSS deposit, was initially discovered in May 2017 through a specialised airborne geophysical survey, which identified an aquifer target size of 562 km2.
A water resource area covering 100 km2 was proven with twelve boreholes, which supported the 3.4 Mtpa throughput scenario outlined in the company’s revised preliminary economic assessment (PEA) released in May 2017.
Recognising the potential and quality of this fresh water aquifer, Orca has recently completed a second programme of six boreholes, expanding the resource area to 135 km2 and increasing the estimated volume capacity of the aquifer to 100 million cubic meters.
This important development removed water availability as a constraint on the throughput enabling the company’s board of directors to approve the design of a 6 Mtpa processing facility at GSS. The completion of the feasibility study incorporating this design scope is expected in early Q2 2018.
Drilling is ongoing at GSS to continue converting inferred to indicated resources and to extend the overall resource below the pit shells that formed the basis of the revised PEA.
Results from the first eight holes of a 25 000 m drill programme were released in October 2017 showing a strong potential for increased resources both within and outside the existing pit shells, which supports the decision to design a 6 Mtpa process plant at GSS.
Orca Gold has defined an indicated resource of 27.6 Mt grading 1.83g/t for 1.63 Moz of gold and an inferred resource of 10.3 Mt grading 1.8g/t for an additional 0.6 Moz of gold (based on a 1g/t cut-off grade at the GSS and Wadi Doum prospects on Block 14.
Mineralisation is robust with true widths up to 85 m and >75% of resources within 150 m of surface.
Feature image credit: Orca Gold