Redbank Mines Limited
ASX Announcement 19 February 2007 1
Redbank Mines Limited
A.C.N. 059 326 519
Level 2, BGC Centre
28 The Esplanade
Perth WA 6000
Phone:
+61 8 9322 6045
Fax:
+61 8 9481 5557
Email:
[email protected]
Website:
www.redbankmines.com.au
ASX Code: “RBM” - shares
“RBMO” - options
Redbank Copper Project – Bluff RC Drilling (Dec 06)
Redbank Copper Project – Diamond Drill Core
Breccia Pipe Material from Punchbowl (Jan 2007)
e-lodgement 8 pages
19 February 2007
NEW COPPER PIPE DISCOVERY AT
PUNCHBOWL
MORE HIGH GRADE COPPER AT BLUFF
MULTIPLE COPPER BRECCIA PIPES TO
BE TARGETED on RBM GROUND
Punchbowl
RC Drilling at Punchbowl has delineated a new copper
mineralised breccia pipe starting 14m below surface to a
depth of at least 300m. Highlights from latest results:
• Hole PB06-9 returned 59m at 1.6% Cu from 38m
including 27m at 2.1% from 38m;
• Hole PB06-8 returned 29m at 2.18% Cu from
96m, with higher grades at depth including 6m at
4.03% Cu from 108m and last 5m of hole ending
in mineralisation and returning 3.10% Cu from a
depth of 120m.
Bluff
The final 3 Holes from this campaign have confirmed the
geometry and consistency of copper mineralisation down
to an expected open pit mining depth of 100m. The latest
assay returns from Bluff include the following:
• 30m at 3.41% Cu from surface, including first 18m
at 4.21% Cu (Hole BL06-13);
• 61m at 2.70% Cu from 47m, including 9m at
5.31% Cu from 59m (Hole BL06-15), with hole
ending in mineralisation;
• 29m at 1.69% Cu from 21m in Hole BL06-14, with
hole ending in mineralisation.
Other Breccia Pipe Targets
In addition to Bluff, Punchbowl and Sandy Flat, 15 other
potentially mineralised breccia pipes have been
identified from limited historical drilling within the
Company’s tenements. These will now be progressively
drilled and evaluated as part of the Company’s planned
staged development of the project.
Redbank Mines Limited
ASX Announcement 19 February 2007 2
Redbank Mines Limited is pleased to report the final instalment of results from its reverse circulation
drilling program completed at the Redbank Copper Project in the Northern Territory during December
2006 and early January 2007. The program was focussed on the Bluff and Punchbowl areas (refer site
map below showing location of main prospects). At Bluff the drilling has confirmed the geometry of the
mineralisation down to an expected open cut mining depth of about 100m and returned spectacular
high grade intercepts. At Punchbowl the drilling has resulted in the discovery of another mineralised
breccia pipe that extends from near surface to at least 290m depth.
Punchbowl
At Punchbowl the drilling program has successfully located a mineralised breccia pipe (Figure 1) that
extends from about 14m below surface to at least 300m. The drilling to date does not fully define the
pipe geometry but it appears to be generally consistent with the known dimensions of the other pipes in
the Redbank area. This round of drilling by the Company has tested the pipe to a vertical depth of
about 100m. However a single diamond drill hole was drilled in the area in 1971 by a Newmont
Australia Pty Ltd led consortium. This hole clearly demonstrates that the mineralisation extends to at
least 300m immediately beneath this latest drilling.
Figure 1 - Punchbowl
Redbank Mines Limited
ASX Announcement 19 February 2007 3
The Company believes that success in locating a mineralised pipe at Punchbowl has very positive
implications for finding similar pipes beneath the other mineralised pipe targets in the project area. The
significant intercepts obtained in the Punchbowl area from this drilling program are tabulated at the rear
of this report (Table 1).
Further drilling is required before a resource can be calculated for the Punchbowl breccia pipe.
Bluff
At Bluff the drilling has confirmed the geometry and consistency of the mineralisation down to an
expected open cut mining depth of about 100m (Figure 2). It has also returned a number of
exceptionally high grades intercepts some starting at the surface. The drilling has also confirmed that
the oxidation profile extends down to a depth of around 40m vertically and is exposed at surface. The
Bluff breccia pipe therefore could provide the initial supply of ore for the Stage 2 oxide leach expansion
of the Redbank Copper Operation with the underlying sulphide ore forming part of the Stage 3 Redbank
sulphides expansion. The significant intercepts obtained from Bluff from this drilling program are
tabulated at the rear of this report (Table 2).
Figure 2 - Bluff
Redbank Mines Limited
ASX Announcement 19 February 2007 4
Redbank Copper Project: Redbank Copper Project:
- Diamond Drill Core from Punchbowl (Jan 2007) - Diamond Drill Core from the Bluff (Jan 2007)
Redbank Volcanic Breccia Pipes
The Redbank Copper Project is located in the Northern Territory near the Queensland border within the
mid-Proterozoic Macarthur River Basin (MCB) (Figure 3). The MCB is host to a number of world class
base metal deposits in both Queensland (the Mt Isa area) and the Northern Territory (McArthur River
area). In the Redbank area copper mineralisation is hosted by clusters of sub-vertical volcanic breccia
pipes that extend through much of the 400 to 500m
thick stratigraphic sequence of the Gold Creek
Volcanics host rocks.
There are known to be numerous possible breccia
pipes in the area, but so far detailed drilling and
resource estimates have only been completed for
two of these, namely
- Sandy Flat, remaining Inferred and Indicated
Mineral Resources of 2 million tonnes at 1.3%
Cu (after mining of high grade cap with average
recorded processing grade through plant of
4.6% Cu in top 40m during mid 1990’s), and
- Bluff, Inferred Mineral Resources of 1.6Mt at
1.6%Cu (refer the Company’s 2006 Annual
Report, page 6 for mineral resources
statement).
Figure 3 - Location of the Redbank Copper Project
Redbank Mines Limited
ASX Announcement 19 February 2007 5
The pipes are ovoid to circular in plan and typically measure 40 to 100m across. Both the Bluff and
Sandy Flat pipes have been shown to be consistently mineralised to depths of at least 300m. Including
Bluff, Sandy Flat and now Punchbowl, there are 5 known mineralised breccia pipes in the project area
where limited drilling has previously been completed (highlighted with red dots in Figure 4). There
are in addition 13 other potentially mineralised breccia pipe targets (ie 18 in total) within the
Company’s ERL 94 area with high grade surface exposed copper mineralisation or high level copper
anomalies in the soil profile. These generally coincide with the location of 14 priority drillholes
proposed (but never drilled) by a joint venture led by CRA Exploration Pty Ltd (CRAE, a subsidiary of
CRA Limited, now Rio Tinto Ltd), in 1995 following a comprehensive data review and extensive soil
geochemistry programme. The Company intends to progressively drill and evaluate these breccia
targets as part of its planned staged development of the project.
Figure 4 - Mineralised Breccia Pipes and Targets
Exploration Context and Priorities
Redbank Mines Ltd is currently targeting to produce 800-1,000tpa of copper from its stockpile leach
operations from Stage 1 of the Redbank Copper Project. Based on existing resources the Company
plans to substantially expand its operations by mining oxides (Stage 2), initially at the Bluff deposit and
then by mining and treating the underlying sulphide mineralisation at Bluff and Sandy Flat (Stage 3).
Redbank Mines Limited
ASX Announcement 19 February 2007 6
The Company has also begun a process of systematic evaluation of mineralised targets in the project
area which could further substantially expand the scope of the project. The first priority has been to
confirm the resources already defined at Bluff and to establish if there was a mineralised breccia pipe at
Punchbowl. The other targets will be progressively evaluated in a priority order to be determined by the
tenor of associated mineralisation, geological controls, physical access on the ground and their
proximity to the existing resources.
With the results from the 2006/2007 drilling program Redbank Mines now has a clear model of the
breccia pipe style of mineralisation at Redbank and a good indication of how that is expressed in
surface mineralisation indications and soil geochemistry. The Company will now seek to build its
resource inventory by progressively drilling the 15 of the 18 identified breccia pipe targets (Figure 4)
yet to be drilled with the intention of finding repetitions of the Sandy Flat, Bluff and Punchbowl breccia
pipes. The Company plans to recommence drilling as soon as possible depending on weather
conditions in the Northern Territory and drilling rig availability.
Yours faithfully,
Redbank Mines Limited
Jerome G Vitale James Searle
Managing Director Executive Director, Exploration
Note
The information contained in this announcement, insofar as it relates to the current drilling, is sourced from information
compiled by Dr D James Searle, B.Sc, PhD, MAusIMM,. Dr Searle is an Executive Director of Redbank Mines Limited and
has sufficient expertise relevant to the style of mineralisation and type of deposit under consideration and to the activity which
he is undertaking to qualify as a Competent Person as defined in the 2004 Edition of the ‘Australasian Code for Reporting of
Mineral Resources and Reserves’. Dr Searle has approved the inclusion of the statement in the form and context which it
appears.
Redbank Mines Limited
ASX Announcement 19 February 2007 7
Table 1 - PUNCHBOWL: Significant (>2m at >0.5%Cu) drilling results from Punchbowl area
(all holes drilled at a declination of 60 deg. towards 180 deg., except PB06-9 which was drilled towards
090 deg.). There has been no cropping of high grade assays. New results not reported to the ASX
previously are highlighted with ▲ symbol.
Hole MGA94
Easting m
MGA94
Northing m
From
m
Intercept
m
Cu %
PB06-3 794 225 8098 600 32 2 0.79
43 2 2.43
PB06-4 794 225 8098 625 34 2 0.55
52 2 1.16
PB06-6 794 150 8098 600 37 2 1.83
46 2 0.64
50 22 1.37
78 2 0.82
PB06-7*# 794 150 8098 625 3 3 0.50
9 2 0.57
19 65 0.98
including 54 8 1.36
71 13 1.52
PB06-8# ▲ 794 150 8098 650 55 2 0.90
60 3 0.50
73 7 1.32
87 5 0.81
96 29 2.18
including 108 6 4.03
including 120 5 3.10
PB06-9 ▲ 794125 8098 600 23 8 0.69
38 59 1.58
including 38 27 2.10
PB06-15 794 200 8098 650 49 6 0.64
PB06-16 794 200 8098 675 66 2 1.16
92 3 1.12
PB06-19 794 175 8098 600 30 6 1.03
41 12 1.17
60 6 0.64
Notes:
* Hole PB06-7 was terminated at 84m down hole in mineralisation due to a collar ‘blow out’.
# Holes that terminated in mineralisation.
Redbank Mines Limited
ASX Announcement 19 February 2007 8
Table 2 - BLUFF: - significant (>2m and >0.5% copper) intercepts. There has been no cropping
of high grade assays. New results not reported to the ASX previously are highlighted with ▲ symbol.
Hole
Easting
(m)
Northing
(m)
Az deg. Dec deg. From m Metres %
copper
BL06-1 796 250 8098 225 050 60 80 44 1.51
including 87 8 2.73
including 99 3 3.41
BL06-2 796 225 8098 225 180 60 surface 34 1.18
including 20 7 2.17
BL06-3 796 225 8098 250 180 60 surface 25 1.00
25 1 0.55
36 3 1.15
39 1 0.62
BL06-7 796 200 8098 225 180 60 surface 11 0.51
12 57 2.06
including 29 25 3.26
BL06-10 796 175 8098 275 180 60 surface 9 0.63
73 37 0.96
BL06-11 796 150 8098 225 90 60 17 8 0.63
BL06-13 ▲ 796200 8098 160 270 60 surface 30 3.41
including surface 18 4.21
BL06-14# ▲ 796200 8098 225 180 60 surface 2 1.23
21 29 1.69
BL06-15# ▲ 796200 8098 200 000 60 47 61 2.70
including 59 9 5.31
#
Holes that terminated in mineralisation.
▲ Indicates newly reported result.
RBM
redbank mines limited
Redbank Mines LimitedASX Announcement 19 February 2007 1Redbank...
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