Nov 23 2010
Robert Friedland, Chairman, and Peter Reeve, Chief Executive Officer of Ivanhoe Australia Limited (TSX:IVA)(ASX:IVA), has announced that continued drilling has intersected exceptionally high-grade copper, gold and cobalt mineralisation at shallow depths in the large mineralised system on the company's Barnes Shaft prospect.
Barnes Shaft, which is part of the Elana M. Trend in the northern Cloncurry tenements, has undergone extensive drilling since August when Ivanhoe announced the discovery of copper, gold and cobalt mineralisation at the prospect.
The most recent drilling, located 100 metres southeast of the discovery hole (BAR0001), has returned the following high-grade result:
Hole BAD0018 - 29 metres @ 3.21% copper, 3.37 g/t gold and 383 ppm cobalt from 210 metres
including - 27 metres @ 3.40% copper, 3.60 g/t gold and 403 ppm cobalt; and
including - 1 metre @ 10.05% copper, 13.35 g/t gold and 800 ppm cobalt.
"These are the highest-grade results ever achieved in a regional drilling program by Ivanhoe Australia," Mr. Reeve said.
"The Elana M. trend has been an extraordinarily productive belt for Ivanhoe Australia, with three recent discoveries. Barnes Shaft is the most impressive of these because of its extensive system size of more than 1.3 kilometres and the depth of its structure.
"To achieve these really very high-grade intercepts of copper, gold and cobalt in such a large system so early in the drilling program gives our team a great deal of confidence that we may have again potentially discovered another significant orebody in this remarkable mineral belt. There is very little drilling close to this high-grade intercept and, as such, the next series of drillholes will seek to extend this high-grade zone along strike and also to depth."
The Barnes Shaft system, geophysically modelled to a depth of 700 metres, consists of flat-lying, supergene enrichment near surface and several deeper, parallel mineralised structures. These structures dip at approximately 60 degrees and range from 5-20 metres thick. The Barnes Shaft system remains open along strike and at depth.
Barnes Shaft is approximately 50 kilometres northeast of the Merlin Deposit (Figure 1) and belongs within a 10- kilometre-long trend known as the Elana M. Trend (Figure 2). The Elana M. Trend is a northwest-trending linear zone of structural complexity that hosts more than six known mineral occurrences, including the Lanham's Shaft molybdenum-rhenium-copper-gold prospect just two kilometres to the north of Barnes Shaft and the Triga copper-gold-cobalt-molybdenum prospect six kilometres to the southeast.
The Barnes Shaft prospect is characterised by a tightly folded sequence of carbonaceous metapelites, feldspar-altered carbonaceous metapelites, variably brecciated calc-silicate rocks and dolerite (Figure 3). Strong northwest-trending shears are observed within the core, commonly forming the contacts between calc-silicates and carbonaceous metapelites. Additionally, these northwest-trending metasediments and shears are cross-cut by numerous east-northeast-trending faults.
Mineralisation at Barnes Shaft consists of chalcocite and chalcopyrite near surface (10 metres from surface) and chalcopyrite at depth (Figures 4 and 5). Both copper-bearing minerals are hosted within brecciated feldspar-altered metapelites and calc-silicate (Figures 6 to 11). Mineralisation appears to be associated with a 1.3-kilometre-long geophysical anomaly that has been modelled to more than 700 metres in depth (Figure 12). To date, this anomaly has been tested over a 700-metre strike length. The majority of this drilling has only been conducted to a depth of 200 metres from surface.
Shallow mineralisation appears to be hosted within several parallel structures ranging from 5 to 20 metres in thickness. These structures dip at around 60 degrees toward the southeast.
Deeper mineralisation has been intersected in three diamond drill holes, of which only one (BAD0018) has assays returned. Strong visual mineralisation of a similar nature to that seen in BAD0018 has been seen in BAD0017 and BAD0021, suggesting mineralisation dips steeply (75 degrees) to the east. Faults form the footwall to mineralisation in all three holes. This fault cross-cuts mineralisation and appears to have offset the mineralisation, raising the possibility of further high-grade copper-gold within an offset zone west of this fault.
Quality Control and Qualified Person Statement
Quality control and assurance programs are implemented in line with the standards of National Instrument 43-101. The exploration program on Barnes Shaft is managed by Mat Brown, BSc(Hons), the Regional Exploration Manager of the Company and a Qualified Person as defined under National Instrument 43-101. Mr Brown has visited Barnes Shaft from 2006 to 2010, and supervised the scientific and technical information contained in this news release.
Source: Ivanhoe Australia Limited