Askari Metals Limited (ASX: AS2) has received promising results from its inaugural field sampling and mapping campaign at the company’s 100%-owned Callawa Copper Project (E45/5842), located approximately 90km north-east of Marble Bar in Western Australia.
The company completed mapping over the tenement, during which several rock chip samples were collected to understand controls on the mineralisation. A brief reconnaissance visit was also undertaken during which several rock samples were collected around the Du Valles copper prospect on the Callawa tenement.
Vice President – Exploration and Geology, Johan Lambrechts, said this part of WA has a reputation as ‘elephant country’ having produced the Telfer goldmine,the Nifty copper mine and more recently, Rio Tinto’s 500 million tonne Winu copper discovery, which is rated as one of the world’s most significant copper discoveries of the past decade
Callawa represents a heavily underexplored opportunity and includes some spectacular historical exploration results that have not been followed up, thereby demonstrating significant exploration potential,” Mr Lambrechts said.
“Our initial exploration efforts have identified some high-grade copper at surface and has extended the zone of known mineralisation on the tenement. Th
“e strike extent of the mineralisation remains open and a gradient array IP survey, potentially followed by a dipole-dipole survey over anomalous targets, is planned to map out areas of interest and potentially extend the strike beyond the area identified by surface outcrop. Further exploration activities will be designed based on the results and targets generated.”
Callawa Copper Project (Askari Metals – 100%)
The Callawa Copper Project covers a large area of the Warrawagine Granitoid Complex on the north-eastern margin of the Pilbara Craton which is a poorly exposed sequence of mafic and ultramafic xenolith-rich foliated gneissic granitoids. Copper mineralisation within quartz veining has been recorded in several locations and is associated with elevated gold values which may indicate a potential porphyry-style origin to the copper occurrence.
The Project is an early-stage exploration project for greenstone hosted vein mineralisation near the margins of ultramafic xenoliths within granites of the Warrawagine complex or potential porphyry mineralisation.
The mineralisation visible at surface comprises secondary copper dominated by malachite within highly altered quartz mineralised and sheared/brecciated host rock. The degree of alteration observed in the samples is indicative of the potential for this to be a part of a major mineralised system.
Historical exploration on the Callawa project is limited in nature, however, it presents indications of potentially significant mineralisation.
The Callawa Copper Project is strategically situated within the north-eastern margin of the Pilbara Craton, and has not seen extensive exploration in the past, with only two minor rock sampling programs and a small 500m air-core drilling program having been completed in the early 2000s.
The historic rock sampling programmes returned results of between 2.5% Cu and 19% Cu with individual results including samples grading up to 9.35% Cu with 25.9 g/t Ag and 7.63% Cu with 15.7 g/t Ag.
Management believes this may hint at the presence of a high-grade epithermal copper system that may be feeding off a deeper porphyry intrusive. The historic air-core drilling programme was positioned to the south of the tenement.
Sampling
Several rock chip samples were collected during the mapping program conducted on Callawa as well as a subsequent reconnaissance field visit. The samples were collected in situ and in areas of good rock outcrop as well as around an area known as the Du Valles workings.
The samples collected around the Du Valles copper workings returned high-grade copper including results such as 6.78% Cu, 4.35% Cu, 2.02% Cu and 1.85% Cu. These results demonstrate the fertility of the geological environment and highlight the significant exploration upside that exists at the project.
The samples were collected along an exposed structure/shear zone which is characterised by malachite staining associated with quartz veining.
The samples collected returned very encouraging copper values over an initial strike length of 125m with a high-grade zone over an initial strike length of approximately 40m. Importantly, the strike length remains open and will be expanded upon through continued exploration at the Callawa project. The samples with elevated copper results also show elevated gold, silver and arsenic.
This combination of copper, gold and trace element results are encouraging and may be used as a vectoring tool. The copper grade was also highest at the edges of the sample lines, maintaining the potential for increasing the already identified 125m mineralised strike further by way of future exploration.