Lefroy Exploration Ltd (ASX: LEX) has used initial results from a geophysical survey to outline a large gravity anomaly at the Mt Day target within its Lake Johnstone project in WA.
The ground gravity survey completed last November comprised a collection of 847 stations in 36 lines with lines spaced at 200 metres and sample points at 100 metres.
Prospective for nickel-copper sulphides
This work complements a survey carried out by Norilsk Nickel Australia in 2008 at the nearby Emily Ann nickel deposit.
Lefroy interprets the gravity high to represent a buried mafic magmatic intrusion, which is prospective for large basal accumulations of nickel-copper sulphide mineralisation.
Close to other deposits
The prospectivity of the Mt Day intrusion is enhanced by its proximity to Emily Ann and the recent Abi Rose nickel discovery, both held by Poseidon Nickel Ltd (ASX:POS).
The Mt Day area has had little drilling activity that has focused on a magmatic intrusion model and remains unexplored.
Follow-up exploration
Further detailed processing of the geophysical data is underway to determine target areas for follow-up exploration.
The key element in the next stage of exploration is to model the basal margin of the intrusion and then plan a deep penetrating ground EM survey to seek conductors, which may represent accumulations of nickel-copper sulphide mineralisation.
- Jessica Cummins