Perth, April 17, 2008 AEST (ABN Newswire) - Copperco Limited (ASX:CUO)(PNK:CPPWF) Announce that a new high grade sulphide copper zone discovered from drilling immediately beneath the proposed copper oxide pit floor at Lady Annie East has returned spectacular copper grades.
Results are:
- 55 metres at 3.30 % Cu from 134 metres including;
-- 27 metres at 5.93 % Cu from 143 metres and
-- 8 metres at 10.62 % Cu from 155 metres
Follow up drilling at Lady Annie East will commence immediately to better understand controls to mineralisation
Significant new sulphide copper intercepts from Flying Horse Deeps drilling include:
- 48 metres at 1.31% Cu from 124 metres
- 60 metres at 1.0% Cu from 122 metres
- 24 metres at 2.57% Cu from 221 metres
- 13 metres at 3.21% Cu from 203 metres, including;
-- 6 metres at 6.42% Cu from 204 metres
Mineralisation extends over 600 metres of strike, up to 400 metres wide and to depths of 300 metres
Resource studies to define a shallow, moderate sized copper sulphide resource is continuing.
Background
The Lady Annie Copper Project is the flagship of CopperCo's Mount Isa tenement holding located 137 km's north of Mount Isa (Figures 1 and 2). The Project currently encompasses oxide copper reserves of 142,600 tonnes from global oxide and sulphide resources of 40Mt at 0.9% Cu, containing 358,700 tonnes of copper metal. Ore Reserve updates are being completed for Flying Horse and Lady Annie and will be announced in the near term.
The Project will initially mine five ore bodies over an eight-year mine life by conventional open pit mining. Ore will be treated by a heap leaching, solvent extraction and electrowinning process (SX-EW). Mining operations commenced in June 2007, development of the mine and processing infrastructure has been completed and first production of copper cathode from the Lady Annie Project occurred in October 2007. The Company will initially produce at an annualised rate of 19,000tpa, ramping up to 25,000tpa by late 2008. In January 2007 CopperCo's exploration objective was to increase the contained copper in the Global Mineral Resource inventory to at least 300,000 tonnes Cu. This objective was achieved in December 2007.
The Company continues to see great potential for further resource development and discovery of oxide copper and recently announced a further production upgrade to the copper oxide leach operation to 30,000 tpa (ASX Release 11 March 2008). Now that a solid foundation has been established for the copper oxide leach operations, the Company will continue to test the potential for further copper oxide resources to replace reserves and assess the potential to extend mine life for the copper oxide heap leach operations. Attention is also being directed at sulphide resources beneath the oxide caps at Lady Annie, Flying Horse, Mount Clarke and Buckley River. The conceptual target for exploration is to ultimately define sufficient suphide copper resources to support a 20,000 tonne per annum 10 year mine life copper in concentrate operation.
Exploration has defined to date 12.7Mt at 0.9% Cu for 111,400 tonnes of contained copper as a sulphide Mineral Resource within the Lady Annie project. Most of these sulphide resources are located at Lady Annie and are beneath the oxide cap on the western side of the Lady Annie ore body. There has been little evaluation of the sulphide potential on the eastern side of Lady Annie (Lady Annie East). The remaining sulphide resources are located at Flying Horse where a deep diamond drilling evaluation of the sulphide potential has been on going since November 2007.
Lady Annie East
The Company is please to announce assay results from diamond drilling beneath the oxide cap on the eastern side of the Lady Annie orebody (Lady Annie East). Very little work both historically and by the company has been done in this area below the copper oxide zone. Since January 2008 five deeper drill holes have been completed targeting potential copper sulphide mineralisation associated with structural faults at depth. Three holes have targeted structures in the north of the Lady Annie East area (LAC062, 064 and 065) and all assays from these holes are pending. CARC 339, one of two holes (the other being LAC 061) targeting a structural intersection in the south, intercepted a significant copper sulphide mineralised zone that includes assayed intervals of:
- 55 metres at 3.30 % Cu from 134 metres including
-- 27 metres at 5.93 % Cu from 143 metres and
-- 8 metres at 10.62 % Cu from 155 metres
Assays are pending for LAC 061. Copper sulphide mineralisation occurs as dominantly chalcopyrite within a stockworked carbonate breccia that is characteristic of the fault zone. These fault zones are generally sub vertical and form the primary feeder to the overlying oxide copper cap.
Within the southern part of Lady Annie East, limited drilling exists beneath the oxide copper cap. Sulphide mineralisation is open in all directions (Figure 3 and 4). A follow up drill programme, stepping out from CARC 339 is due to commence shortly to test the mineralisation potential and to better understand the controls to mineralisation in the zone.
Flying Horse Deeps
The Company is also pleased to announce further broad, high grade copper sulphide results from an on-going drilling programme being undertaken at Flying Horse to assess the copper sulphide potential beneath the currently defined oxide copper Mineral Resource and Ore Reserve.
Drilling to date has comprised full or partial completion of 37 drill holes for 10,291 metres comprising Reverse Circulation "pre-collars" for 1,942 metres and diamond core "tails" for 8,350 metres. Complete results have now been received for 31 of 37 completed drill holes. Significant sulphide copper results include:
- 48 metres at 1.31% Cu from 124 metres from FHD040
- 60 metres at 1.0% Cu from 122 metres from FHD041
- 24 metres at 2.57% Cu from 221 metres from FHD041, including
-- 6 metres at 6.42% Cu from 204 metres
- 13 metres at 3.21% Cu from 203 metres from FHD024
- 15 metres at 1.86% Cu from 81 metres from FHD031
- 14 metres at 1.08% Cu from 180 metres from FHD023
Strongly mineralised zones are associated with disseminated and/or vein hosted chalcocite and chalcopyrite within strongly sheared and brecciated dolomitic siltstones of the Gunpowder Creek Formation.
The geological model of the prospect is evolving with each deeper drill hole. Drilling is primarily targeting 4 structural domains beneath the Flying Horse oxide copper cap. Three of these domains are defined by a series of parallel, subvertical faults termed the Western, Central and Kelly Fault zones. These three zones intersect a low angle thrust termed the Spinifex Fault at depth. It is believed that the intersection of the Spinifex fault and the subvertical structures provides the focus for the majority of mineralisation intersected to date.
The potential for a modest tonnage, shallow sulphide resource will continue to be investigated. Preliminary resource studies have commenced.
Given the shallow nature of the sulphide systems, the Company would look to sequentially developing the potential resource through open cut mining methods rather than underground, at the completion of the oxide mining phase at each pit operation.
Mr SJ Pooley (MAusIMM, MAIG), a geologist employed full-time by CopperCo Limited, compiled the technical aspects of this report. Mr Pooley is a member of the Australasian Institute of Mining and Metallurgy and has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity that is being reported on to qualify as a Competent Person as defined in the 2004 edition of the "Australasian Code for Reporting of Mineral Resources and Ore Reserves". Mr Pooley consents to the inclusion in the report of the matters in the form and context in which it appears.
Contact
Brian Rear
Managing Director
Tel: +61-8-9260-8800
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