THE HAMAMA WEST DEPOSIT
The Hamama West deposit has an NI 43-101 compliant mineral resource estimate (“MRE”), based on 74 diamond drill holes, and published in January 2017. The mineralisation at Hamama West is hosted within a stratiform and stratabound tabular silica-carbonate host rock, and consists of primary sulphide mineralisation, overlain by a weathered gossan zone (the “gold oxide cap”) consisting of oxide and transitional mineralisation types. The Hamama West mineralisation has a strike length of approximately 675m, over an average surface width of c. 60m. The gold oxide cap extends to an average depth of 35-50m below ground level. The deepest drillhole to date (AHA-073) has intersected the mineralised sulphide zone down to a depth of 275m below surface, and it remains open at depth. The Crocs Nose Zone is a small subsidiary body of oxide mineralisation located slightly to the southwest of the Hamama West Main Zone, and represents a sinistral strike slip offset of the Main Zone. The gold oxide cap at Hamama West has been the focus of Aton’s recent development efforts, as a potential open pit mine and heap leach processing facility.
Significant additional oxide mineralisation has also been identified from surface at Hamama East, but this requires further delineation and has not yet been included in an MRE or the Hamama West development studies. The limited diamond drilling to date at Hamama Central has intersected a zone of Au-Ag-Zn mineralisation, which returned intercepts including 14.1m @ 0.81 g/t Au, 42.5 g/t Ag and 6.51% Zn (hole AHA-004) and 16m @ 0.81 g/t Au, 16.2 g/t Ag and 4.71% Zn (hole AHA-005), and further work is required in this area.
Preliminary metallurgical (bottle-roll) test results on the gold oxide cap indicated recoveries of up to 92.2% Au and 65% Ag. Column leach metallurgical testwork showed recoveries of >75% Au from oxide and >72% Au from transitional mineralisation from the Hamama West gold oxide cap.