Early nickel exploration at Leinster was undertaken during the 1960’s and 1970’s, most notably by WMC, Seltrust, Amax and BP Minerals. Some grassroots gold and nickel exploration were undertaken during and since the 1980’s primarily by Outokumpu, Dominion, Forrestania Resources, Dalrymple Resources, Miralga Mining and Lionore.
A large, comprehensive database of exploration data from this period has been reviewed and highlighted numerous untested to partially tested nickel prospects within the Leinster project area.
The project area straddles the Weebo – Mt. Clifford greenstone belt and the Agnew-Wiluna greenstone belt, within the Kalgoorlie Terrane to west and the Kurnalpi Terrane to the East, which are Archaean granitegreenstone terranes that make up part of the Eastern Goldfields province of the Yilgarn Craton.
This northnorthwest trending belt consists of a folded and thrust stacked sequence of basalts, ultramafics, felsic volcanics and pelitic sediments, intruded by several granitoid plutons. The area is also transected by a splay of the north-northwest trending Perseverance Fault (part of the Keith-Kilkenny lineament) in the centre, and the north striking Mt. McClure shear zone in the east.
The Horn Deposit
In 2008 Breakaway Resources Ltd, which was acquired by Minotaur in 2013, calculated a JORC (2004) compliant Inferred Mineral Resources estimate for the Horn deposit of 0.6Mt @ 1.4% Ni and 0.3% Cu for 8,300 tonnes of contained nickel and 1,800 tonnes of contained copper.
Massive and matrix nickel sulphide mineralisation at the Horn Deposit was drilled by Breakaway over a 500m strike length and remains open along strike to the north and south and is up to 15m thick. The nickel mineralisation is coincident with a prominent magnetic ultramafic succession and is located on the southern extremity of the ultramafic unit.
The resource estimate is based on 11 diamond and 1 RC drillholes carried out on a nominal 50m by 50m spacing. The deposit boundary was defined by a 0.5% Ni cut-off grade, which coincides with the geological boundary of disseminated/matrix sulphides.
The Horn deposit has significant proximal and regional exploration potential with numerous untested or partially tested bedrock EM conductors. Auroch will systematically advance exploration, initially targeting resource extensions and high-grade ore plunges prior to examining regional opportunities.
The Valdez target is located northeast of the project area on tenement M36/475 and lies along strike from the Waterloo nickel sulphide deposit owned by Saracen Minerals Limited. Historic drilling in the area is only shallow, however a drillhole over the top of the southern edge of the of the anomaly intersected up to 0.5% nickel. The target remains under-tested having only one drill-hole in a 1200m by 450m modelled EM plate, and warrants further exploration.