Mount Kelly is a series of prospects 20 km south east of Lady Annie and adjacent to the Lady Annie Operations processing facility. Like Lady Annie, Mount Kelly has a long history of exploration with limited exploitation.
The Mount Kelly Project area has been the subject of several exploration campaigns by various companies since the 1960’s (Figure 7). The main prospects identified in the project area to date comprise:
- The Mount Clarke oxide copper deposit;
- The Flying Horse and Mount Kelly Workings oxide copper deposits;
- The MK475 (or Mount Kelly Fault) sulphide copper-gold deposit; and
- The nearby Swagman, Macleod Hill and Dividend oxide copper prospects.
Mount Clarke was discovered in 2003 and is now the site of Lady Annie Operation’s first open pit. Three more targets were identified by CopperCo in 2005 after reviewing the previous drilling data and subsequently, three more oxide copper deposits were discovered in 2005 - Flying Horse, Mount Kelly Workings and Swagman. All three deposits are within 1.5 km of Mount Clarke.
Mount Clarke
The Mount Clarke oxide copper deposit is a sub-horizontal blanket of up to 35 m thick, extending from surface to a depth of around 80 m. The deposit is hosted within a northwesterly trending fault zone approximately 100 to 150 m wide striking for over 700 m. The fault zone is a first order splay off the regional northwest trending Mount Kelly fault and is characterised by close spaced subvertical shears within weakly laminated dolomitic siltstones.
The sub-vertical shears provide strong structural control to the secondary oxide copper “blanket” developed above localised supergene chalcocite concentrations. The oxide copper zone is up to 60 m thick and ranges from surface to 80 m depth striking over a 800 m length. The resource estimate covers a strike length of 700 metres and is limited to a depth of 100 metres. Deeper drilling is currently underway to assess the sulphide potential below the transitional zone (Figure 8).
Flying Horse
Flying Horse is located 200 metres south from Mount Clarke. From 2005 to 2007, the Company completed a significant RC and diamond drilling programme. The drill results confirm that Flying Horse is developing into a significant oxide copper source. The diamond drilling, in conjunction with surface mapping, has increased the understanding of the structural controls to the mineralisation that has underpinned the confidence level applied to the Mineral Resource estimate.
Mineralisation is controlled by a series of sub parallel en-echelon shear zones trending west-northwest associated with a splay off the Mount Kelly fault.
Extensional and infill RC and diamond drill programmes at the Flying Horse Extended Prospect are continuing. (Figure 10) The ongoing programmes will significantly add to the Mineral Resource at Flying Horse (Figure 11).
Flying Horse Sulphide
Significant primary copper-gold mineralisation has been outlined along the Mount Kelly Fault located to the immediate west of the Mount Clarke oxide copper deposit and beneath the Flying Horse oxide deposit. Current drilling in the area is focused on further defining the extents of the deposit where there is potential for extensions of primary copper mineralisation along the strike of the Mount Kelly Fault.
Mount Kelly Workings
The Mount Kelly Workings prospect is a discrete zone of oxide mineralisation located approximately 100m to the southeast of Flying Horse. At Mount Kelly Workings, an RC and diamond programme was completed targeting outcropping oxide copper mineralisation in and around small scrapes and workings. The programme was designed to test for shallow oxide copper at the intersection of the Spinifex Fault and Mount Kelly Fault structures.
Oxide copper mineralisation is focused within the axial zone of a shallow plunging anticline where it is intersected by the north-northwest trending Mount Kelly fault and the west-northwest trending Spinifex thrust. Remobilisation of copper minerals is evident away from the controlling structures along bedding and axial cleavage planes.
Swagman Prospect
The Swagman prospect is located approximately 1.5km to the south of Flying Horse. Whilst this zone of mineralisation is currently smaller than both Mount Clarke and Flying Horse, it is near surface and hosted within competent siltstones and sandstones. These host rocks are very similar to Mount Clarke and Flying Horse and boast excellent leach kinetics from recently completed metallurgical testwork.
Mount Kelly Regional Targets
At McLeod Hill, some limited drilling was previously completed by CRA along the McNamara Fault and returned oxide copper intersections of up to 16 m at 2.82% Cu. The Dividend Prospect, located 3 km east of the Mount Kelly Workings, is a structurally complex area associated with highly anomolous copper-gold values in iron-rich outcrops along possible fault structures. Drilling by CRA and Reefway at the Dividend Prospect has intersected minor oxide copper mineralisation with elevated gold values. CopperCo has not drilled these areas as yet. However they represent high priority, early stage exploration targets that could potentially contribute to an expansion of the oxide copper inventory within the project area.
The Lady Maggie prospect is situated approximately 15 km south of the Lady Annie Operations processing facility at Mount Kelly and around 100 km north of Mount Isa. Historical records suggest that approximately 4,000 t @ 7.5% Cu were extracted from an exploration shaft and transported to Mount Isa for processing. Mineralisation comprises high grade oxide copper, principally malachite and azurite and primary copper minerals present at depth exploiting an east-west fault structure believed to be a splay of the north-south trending McNamara’s Fault.
