Surefire Resources is following up newly-found base metals soil anomalism at its Yidby East gold project in Western Australia’s Mid West region, with renewed exploration set to test for possible Golden Grove-style deposit analogues.
The broad-scale anomalous copper-zinc was identified at the company’s Phat Boy target, which sits about 50km south/south-east of 29Metals’ renowned Golden Grove copper-lead-zinc-gold-silver operation and other nearby volcanogenic-hosted massive sulphide (VHMS) deposits in the same belt. The Phat Boy project occupies a separate tenement east of and contiguous with the company’s Yidby gold project.
While previous exploration of the area has been directed mainly towards its gold potential, Surefire’s extensive research and base-metal anomalism identified from its scout soil sampling results has led it to believe that there is plenty of reason to consider the project’s potential for other commodities.
Surefire Resources managing director Paul Burton said: “The tenor and coincidence of the copper and zinc results are very anomalous and enhance the prospectivity of our Yidby Project tenements. The analogies to Golden Grove and the extent of the anomalism provides ample room for significant mineralisation to occur below surface.”
Burton also says the company’s next phase of sampling is expected to “tighten up the anomalies” and define the type of drill targets that could help it build a major project.
Surefire’s recent soil sampling program comprised 161 samples collected from across a broad-spaced grid comprising north-to-south lines ranging between 500m and 1200m long and spaced 250m apart.
Sample analysis was undertaken by Nagrom Laboratories in Perth. All samples were assayed for gold, platinum and palladium by the laboratory’s fire assay method and for a full base metals element suite by its x-ray fluorescence technique.
The company says it has identified four coincident zones of anomalous copper and zinc, with dimensions ranging between 400m by 500m and 1000m by 500m. The four robust zones are arrayed along the total length of the grid and appear to remain open at the northern end, but close off at the south.
Peak copper values occupy contours exceeding 220 parts per million, while zinc values fall within a 100ppm contour. The zones are disposed almost nose-to-tail along a minimum of four sample lines and all strike emphatically along a north-easterly strike, coinciding with a persistent, mapped south-east dipping fault for at least 2.1km.
The fault coincides with the slightly arcuate north-west face of the most extensive and prominent line of banded-iron formation (BIF) in the property and all of the copper-zinc anomalism follows the northern edge of the fault.
Surefire sees strong parallels between the geological and structural environments at Yidby and Golden Grove, with both sitting in the Warriedar Fold Belt that features extensive mineralisation all the way north to Golden Grove and also south to Capricorn Metals’ Mount Gibson gold project.
While Mount Gibson was most recently mined for gold in both open-pit and underground operations, it was also explored as a gold-copper-zinc-rich VHMS deposit, which was overprinted by a subsequent hydrothermal gold mineralising event.
Surefire has applied to the WA Government for co-funding of its proposed follow-up exploration drilling under the exploration incentive scheme (EIS). The drilling program is aimed at confirming the geological model for a possible VHMS setting at Yidby and to further test its initial geochemical targets.
The company is planning to conduct more detailed soil sampling starting next week to close up the current grid and refine the extent, character and controls of the anomalism, in addition to rock-chip sampling and mapping of key anomalies to produce drill targets.
With strong, coherent base metal anomalism and potentially-related gossans in the BIF zones at Yidby, which is sandwiched between major proven VHMS-style deposits in the same litho-structural belt, it looks like Surefire has found the best possible place to start looking for a new VHMS deposit.
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By Doug Bright
