Hawiah is located within the Wadi Bidah Mineral District (“WBMD”) in the southwest of the Arabian Shield.
G&M commenced drilling at Hawiah in September 2019 and quickly confirmed that large-scale Volcanic Massive Sulphide ("VMS") style of mineralisation underlies the gossanous ridgeline. Three distinct copper-zinc-gold-silver massive sulphide lodes have been intercepted in drilling consistently over more than 4 kilometres of strike length, with intercepts of up to 5% copper equivalent. KEFI released the key outcomes of the initial Preliminary Economic Assessment (“PEA”) for the Hawiah Project in September 2020.
The Hawiah EL covers a predominantly bimodal mafic and felsic volcaniclastic succession in a broad anticline, with an unusually large expression of surface mineralisation outcropping on the eastern limb. Hawiah’s silicified and gossanous horizon was mapped and trenched by France’s Bureau De Recherches Geologiques et Minieres (“BRGM”) in the 1980s, which identified its gold-bearing potential.
The geological setting of Hawiah appears analogous to other large VMS deposits in the Arabian-Nubian Shield that have well-preserved, mature oxidised zones enriched in gold at surface.
Initial surface exploration confirmed that the main gossanous ridgeline is enriched in gold and the mineralisation has good continuity along strike, as well as containing abundant secondary copper showings. Field work undertaken prior to drilling included trenching, geological mapping, geophysical surveys and satellite imaging programmes.
Successful Hawiah Drilling Programmes
A total of 69 diamond drilling drillholes were completed at Hawiah by May 2020. This drilling identified three zones with the following preliminary parameters for potentially mineable massive sulphide lodes, with all zones remaining open at depth:
- The ‘Camp Lode’: 1.2 kilometres long, with an average width of 7.5 metres with the widest intersection of 20 metres found at a depth of 90 metres. The lode has been drilled to a depth of 300 metres where 9 metres true width of massive sulphide was intersected;
- The ‘Crossroads Lodes’: 800 metres long, with an average width of 5 metres with the widest intersection being 8 metres true width. This lode has been explored to a maximum vertical depth of 350 metres where 7 metres of massive sulphide was intersected; and
- The ‘Crossroads Extension Lode’: 1,000 metres long, with an average width of 5 metres with the widest intersection being 12 metres true width. This lode has been explored to a maximum vertical depth of 270 metres where 9 metres of massive sulphide was intersected.
Long section showing extent of VMS mineralisation at May 2020
Exploration potential remains significant at depth below all areas. The downdip continuation of Camp Lode is of particular interest with the deepest two holes intercepting:
- 1.27% copper over a true width of 9 metres in HWD_005; and
- 1.55% copper over a true width of 7.5 metres in HWD_059.
Drilling has also extended the gold-mineralised oxide zone from surface:
- Surface trenches reported encouraging gold grades in 2015 before the field programme was suspended at that time for since-resolved security and regulatory obstacles; and
- Initial drilling has returned an average grade of 1.7g/t gold across 7 drill holes with an average vertical depth of 35m.
Hawiah Mineral Resource Estimate
In August 2020, KEFI announced the maiden Hawiah Mineral Resource Estimate (“MRE”) totalling 19.3 million tonnes (“Mt”) at 0.9% copper, 0.8% zinc, 0.6 g/t gold and 10.3g/t silver.
Further information regarding the Hawiah MRE is in the KEFI announcement “Hawiah Maiden Resource” released 19 August 2020.
Preliminary Economic Assessment
KEFI released the key outcomes of the initial Preliminary Economic Assessment (“PEA”) for the Hawiah Project in September 2020. The positive PEA included the following outcomes:
- confirms Hawiah is a high priority Project, with a significant maiden resource after only seven months of initial drilling;
- the maiden resource alone potentially supports a production rate of 2Mt p.a. for seven years for net operating cash flow of c.US$70 million p.a. at current metal prices. After initial and sustaining capital expenditure of c.US$222 million and c.US$46 million respectively, this would indicate an estimated net cash surplus of over US$200 million before financing costs and tax; and
- clear potential for expansion of resources with further drilling below the currently drilled depth of 350 metres of this structurally consistent tabular structure. A doubling of the resource with material of similar characteristics as the maiden resource would indicate an estimated net cash surplus of over US$500 million before financing costs and tax.
- VMS deposits;
- volcano-sedimentary deposits associated with disseminated to sub-massive sulphides; and
- shear zone & quartz vein hosted deposits.
VMS deposits are often major copper-lead-zinc-gold-silver orebodies and examples of large VMS deposits in the ANS include:
- Eritrea - Bisha (Nevsun/Zijin) and Asmara (Sichuan Road & Bridge Mining Investment Development) deposits;
- Sudan - Hassaii (Ariab) deposits; and
- Saudi Arabia - Jabal Sayid (Barrick and Ma’aden) and Al Masane (Al Kobra Mining) deposits.
The Hawiah EL and the surrounding under-explored WBMD are considered to be very prospective for gold and VMS deposits.