Kooline Lead – Silver Project

Project Overview

Surefire Resources Kooline silver-lead-copper-gold project is located in the Ashburton Basin.

The Kooline Project tenements cover an almost 50km strike length of mineralised Ashburton Formation and are located 55 kilometres south of the 1 Moz Paulsen’s gold mine and 190 kilometres WNW of Paraburdoo in the Ashburton province of Western Australia (Figure 1).

The tenements include the previously mined high-grade lead (Pb) – silver (Ag) +/- Copper (Cu) lodes of the Kooline Mineral Field (Figure 2) where previous rock chip sampling of the exposed lode structures produced grades of up to 55.3% Pb and 249 g/t Ag from the Bilrose workings and copper grades of up to 2.62% Cu (including 12% Pb) from the Phar Lap workings (ASX:SRN release 22 May 2018).


Figure 1: Kooline Project Location

VTEM Modelling

As announced to the ASX on 25 May 2021, qualitative interpretation of VTEM data over E08/2373 identified a conductive complex that was inferred to be caused by a large intrusive body.  This intrusive may represent a heat and potential mineralised magmatic fluid source for an intrusive related “intracratonic magmatic copper-gold” or IMCG system (ASX:SRN release 14 December 2018) and is seen as particularly significant.  Work conducted by CSA Global on behalf of the Company highlighted the potential for IMCG-style mineralisation in this belt.

To gain a better understanding of the identified conductors’ geometry and quality, the VTEM data were modelled using Geoscience Australia’s 1D Layered Earth Inversion software (program GALEI).  This creates flight line by flight line geo-electric model sections or Conductivity-Depth-Inversion sections (CDI) which show the variation of conductivity of the earth with depth that can explain the signal recorded.  All CDI data is then amalgamated and depth slices constructed to give a plan view of the resultant conductors modelled.


Figure 2: VTEM time slice over the Kooline silver-lead field showing historic mines and mineralised trends, E08/2373.

Three High Priority Conductors Identified

Inspection of the CDIs and recorded response profiles identified three high priority targets (Figure 4).

Mt Conspicuous: Associated with the historic Mt Conspicuous Mine, this strengthens to the east, having in excess of a 600m strike length.  The conductor appears to dip moderately to the south.  It is modelled as shallow as 10m from surface and persists to 400m depth.  In cross-sectional view it appears to have two major conductive masses associated with it that may represent a structural thickening of the conductor (Figure 3).

Figure 3: Mt Conspicuous EM target, one of three high priority targets identified at the Kooline Lead-Silver Field. Depth scale is a x10 exaggeration of horizontal scale. Red represent high conductivity.

Northerly: Identified from 13 to 400m depth, but developing well at about 100m depth this conductor has an apparent strike length of 400m.  It appears to be an en echelon repeat of the Phar Lap North anomaly, itself appearing to be an en echelon repetition of the conductor associated with the Phar Lap Mine (Figure 4).  While the mine produced only 10 tons Pb, it stands out as having a strong copper association with grades up to 2.62% Cu in the mine and 3.74% Cu in selective rock chips from the mine area.

Phar Lap NW: Having an apparent strike length of about 800m, this conductor is also modelled from shallow depths to in excess of 400m.  It appears to plunge to the southeast; the EM anomaly migrating in that direction with time.


Figure 4 : VTEMCDI at 110m depth slice. E08/2373. Bright areas signify modelled bedrock conductors at 110m, GDA94 MGA Zone 50.

Conductors Related with Historic Mines

In addition to the high priority conductors identified above, a large proportion of the historic mines have associated with them significant EM responses:

Dingo: 220 tons Pb and 2,439 oz Ag were mined at this site.  A strong conductor has been identified coincident with the mine, extending to depths beyond that mined (Figure 4).  No drilling has occurred on this site.

Phar Lap: A strong conductor occurs to the north of the historic Phar Lap Mine (10t Pb, 137oz Ag).  While the site was drilled in 2009, with anomalous but low grades of Pb, and Cu intersected, the conductor is developed further to the north and remains untested.

Proposed testing of identified conductors

Surefire intends to test the identified conductors with a mix of ground EM surveying and RC drilling.  As announced on 25 May 2021, Surefire has attracted a $150,000 co-funding grant for exploration drilling from the WA Government.