Copper and zinc was mined here back in the 1960s and up to 2006 when it was processed at Radio Hill. Now, we are developing this project with a new JORC Resource of 2.6Mt at 1.14% copper and 1.12% zinc.
The Whundo Cu-Zn deposit is located approximately 12.5 km southeast of the Radio Hill plant. The deposit had been previously mined by Fox Resources during 2005-6 in two open pits.
AM&A estimated the total Indicated Oxide and Sulphide/Fresh Mineral Resources remaining at Whundo/West Whundo outside the abandoned open pit in October 2018
|Tonnes (kt)||Cu %||Zn %||Cu Metal (t)||Zn Metal (t)|
Deposit geology and mineralisation
The copper/zinc deposit at Whundo and West Whundo is confined to a single stratigraphic horizon as a series of NW to NNW plunging shoots that outcropped as a sinuous line of discontinuous goethite-hematite gossans that could be traced for some 500 m along strike. Individual ore shoots have a restricted strike length and are commonly 1-5 m thick but reach a maximum thickness of 20 m in the hinge zone of two small upright synclines in the axis of the major synclinal structure where they form the Whundo and West Whundo deposits. The ore shoots plunge about 35-40° to the NW and extend down plunge as much as 150 m.
Primary sulphides, mostly pyrrhotite, pyrite, sphalerite and chalcopyrite are only preserved below the weathering profile (often below a depth of 30 m). No galena or any other lead minerals have been reported from these deposits.
Modern exploration at Whundo commenced in the 1960s with Fox eventually mining part of the Oxide resource in 2005-2006.
A total of 870 percussion and diamond holes for 52,586.44 m were drilled into the deposit prior to Fox mining the deposit. Artemis drilled a further 56 RC drill holes for 3,528 m following QAQC procedures meeting JORC Code (2012) requirements in-filling some of the previously drilled resources and to confirm by drilling several twin holes the reliability and accuracy of the historic drilling. The Artemis drilling confirmed that the historic drilling was sufficiently reliable for an Indicated Mineral Resource estimate reported in accordance with the JORC Code.
Whundo regional geology
AM&A modelled the Whundo/West Whundo deposit using all the available drilling, including the Artemis 2018 and historic drilling, with MineMap© software by interpolating grades with an inverse distance squared algorithm within a mineralisation wireframe interpreted from drill assay intersections. The model and estimate was adjusted to accommodate previous mining.
The mineralisation wireframe was modelled to reflect the geometry of the individual shoots. The envelope was based on a metal factor combination of Cu and Zn assays where the boundary value metal %, was Cu%+Zn%*($2457/$6058) >0.5 where the $ values reflect the London Metal Exchange values for copper and zinc metal per tonne in September 2018.
This method of boundary definition was selected due to the correlation observed between copper and zinc, and the potential for these to be recovered through a proposed flotation circuit at Radio Hill. Some internal dilution was included to facilitate improved continuity with other adjacent drill intersections. Internal dilution was not included if the result was to reduce the total intersection below 0.5%.
The copper and zinc grades were estimated separately using inverse distance squared estimation, with the search ellipse reflecting the geometric continuity of the interpreted geology. The interface between oxidised and fresh mineralisation, the transition surface base, is generally about 35-45m below natural surface.
The total Indicated Oxide and Sulphide/Fresh Mineral Resources remaining at Whundo/West Whundo was estimated, and reported below the abandoned open pit, above a 0.2% Cu% lower cut-off as 2.7 Mt at 1.1% Cu and 1.1% Zn.
Whundo Cross section (492500E - looking west)
We inherited the Whundo tenements through the Fox Radio Hill Pty Ltd deal for the Radio Hill processing plant – hence we gained the Whundo copper project. Additionally, there is the Whundo and Ayshia copper/zinc deposits, with a focus on zinc:
|M47/7||1,955,000||Copper = 0.43%||3,289 t|
|Zinc = 1.93%||22,911 t|