June 28, 2007
FOR IMMEDIATE RELEASE
7.0 MILLION TONNE TAILINGS RESOURCE ADDS
TO WOODLAWN FEASIBILITY STUDY
Tri Origin Exploration Ltd (TOE: TSX-V) is pleased
to announce that its 51%-owned subsidiary, Tri Origin Minerals Ltd (TRO) has
completed a Resource estimate for the Woodlawn Tailing’s Retreatment
Project (WRP) West and South tailings dams. The JORC(1) compliant
Measured and Indicated Resource is
6.98 million tonnes grading 0.55% copper, 1.34% lead, 2.31%
zinc, 0.31 grams per tonne gold and 30 grams per tonne silver.
An additional Inferred Resource of
1.61 million tonnes at similar grades has also been calculated. The third dam
of the WRP, the North tailings dam, is yet to be drilled and evaluated. Based
upon historic Woodlawn mine production reconciliations it is anticipated that
an additional 2.5 million tonnes of tailings may be defined within this third
dam.
The Woodlawn Tailings Retreatment
Project and Woodlawn Underground Project are being evaluated by TRO on an
integrated basis as part of a bankable feasibility study to redevelop the
past-producing Woodlawn mine. This study is on schedule for completion during
the first quarter of 2008. Statutory approvals are being run in parallel with
the study and are on schedule for completion by mid 2008.
The tailing resources (Tables 1, 2 and
3) for the West and South tailings dams have been independently estimated by Mr
Robin Rankin of GeoRes (GeoRes), Sydney,
Australia.
Table 1: Combined
Tailings Resource Estimate 2007
Resource Category
|
Tonnes
|
%
Tonnes
|
Cu (%)
|
Pb (%)
|
Zn (%)
|
Au (g/t)
|
Ag (g/t)
|
Measured
|
3,890,000
|
45
|
0.55
|
1.34
|
2.31
|
0.31
|
30
|
Indicated
|
3,090,000
|
36
|
0.54
|
1.33
|
2.20
|
0.31
|
29
|
Inferred
|
1,610,000
|
19
|
0.51
|
1.18
|
2.26
|
0.24
|
24
|
Total
|
8,590,000
|
100
|
0.54
|
1.30
|
2.26
|
0.29
|
28
|
Table 2: West Dam Tailings Resource Estimate
2007
Resource Category
|
Tonnes
|
%
Tonnes
|
Cu (%)
|
Pb (%)
|
Zn (%)
|
Au (g/t)
|
Ag (g/t)
|
Measured
|
2,030,000
|
51
|
0.61
|
1.46
|
2.01
|
0.39
|
35
|
Indicated
|
1,550,000
|
27
|
0.59
|
1.50
|
1.91
|
0.39
|
36
|
Inferred
|
370,000
|
22
|
0.60
|
1.49
|
1.80
|
0.37
|
33
|
Total
|
3,960,000
|
100
|
0.60
|
1.48
|
1.95
|
0.39
|
36
|
Table 3: South Dam
Tailings Resource Estimate 2007
Resource Category
|
Tonnes
|
%
Tonnes
|
Cu (%)
|
Pb (%)
|
Zn (%)
|
Au (g/t)
|
Ag (g/t)
|
Measured
|
1,860,000
|
40
|
0.48
|
1.20
|
2.63
|
0.22
|
25
|
Indicated
|
1,540,000
|
33
|
0.50
|
1.15
|
2.49
|
0.22
|
21
|
Inferred
|
1,240,000
|
27
|
0.48
|
1.09
|
2.40
|
0.20
|
21
|
Total
|
4,630,000
|
100
|
0.49
|
1.15
|
2.52
|
0.21
|
23
|
Note:
Numbers are rounded up or down and hence may not appear additive.
The Woodlawn property located 200
kilometres southwest of Sydney,
New South Wales was acquired by
Tri Origin in 1999 and was considered a key asset of the Company during the ASX
listing of its subsidiary in 2004. The Woodlawn mine operated from 1978 to1998
milling approximately 13.8 million tonnes of high grade ore from open pit and
underground operations. The operations closed due to prevailing low metal
prices and corporate reasons.
In October last year TRO released a
Measured and Indicated Resource estimate for the underground component of the
Woodlawn Zinc project of 8.58 million tonnes grading 1.8% copper, 4.0% lead,
10.3% zinc, 0.54 grams per tonne gold and 84 grams per tonne silver. Based on
this resource, a pre-feasibility evaluation of the underground component of the
Woodlawn Zinc project was subsequently completed with positive results. TRO is
now progressing a bankable feasibility study for Woodlawn and the new tailings
resource estimate will be integrated into that study. The combined Measured and
Indicated Resource for the property now stands at 15.6 million tonnes. This
will be the first economic evaluation of an integrated underground and tailings
retreatment operation.
A positive economic evaluation from
the bankable feasibility study would likely result in a tailings retreatment
project in the order of 1.5 million tonnes per annum and an underground
operation producing 440,000 tonnes per annum. In effect TRO is pursuing the
development of a near 2 million tonnes per annum operation at Woodlawn. The
advantage of an integrated project would be the potential to blend a low grade
concentrate from the tailings with that of higher grade concentrate produced
from underground ore and the potential benefit of operating economies of scale
given the combined tonnage throughput. The overall potential of the Woodlawn
Zinc Project is to produce 120,000 to 130,000 tonnes per annum of concentrates
at the site.
The capital requirements for this
project will be determined by the bankable feasibility study. It is now
estimated by TRO that capital costs may be in the order of $150 million.
Tailings Resources have been estimated by GeoRes using a validated
database comprising data from 88 drill holes and survey data of dam and
tailings surfaces. The significant percentage of Resources in the Measured
(45%) and Indicated (36%) categories at both the West and South tailings dams
(Tables 2 and 3) is a function of reliable geostatistical characteristics
resulting from high data density. This, combined with conservative
extrapolation parameters explains the relatively small percentage of Inferred
Resources. Additional drilling in the future, including the north dam, would
further increase the confidence of contained metal within the dams. Where
historical operating records from the Woodlawn Mine were available these were
reconciled with dam volumes and grades. These reconciled within the confidence
levels of the Resource estimates. TRO considers that the existing definition is
sufficient to complete an economic evaluation for the bankable feasibility
study.
(1) Declaration
and JORC Compliance: The information in this
release that relates to Mineral Resources or Ore Reserves is based on information
compiled by Robin Rankin, a Member of the AusIMM, and registered as a Chartered
Professional Geologist (CPGeo). Robin Rankin is Principal Geologist and
operator of GeoRes. He has sufficient experience relevant to the style of
mineralization and type of deposit under consideration, and to the activity
which he is undertaking, to qualify as a Competent Person as defined by JORC.
He consents to the inclusion in the report of the matters based on his
information in the form and context in which it appears.
This release was prepared by Tri Origin
Exploration Ltd. from information supplied by its subsidiary Tri Origin
Minerals Ltd (TRO). TRO’s news release can be publicly accessed at www.asx.com.au under Listed Company Documents
filed by TRO. TRO’s reporting of mineral resources, exploration results
and qualifications of competent persons are in accordance with the 2004 Edition
of the Australasian Code for Reporting of Exploration Results and the JORC Code
of December 17, 2004. Although these codes may differ in some regards to
Canadian Standards including NI 43-101, it is the opinion of TOE management
that statements made in the TRO report are, in all material regards, compliant
with NI 43-101standards.
For further information please contact:
Tri Origin Exploration Ltd.
Dr. Robert Valliant, President
Tel: (905) 294-9942.
Web page:www.triorigin.com
E-mail: invest@triorigin.com
Tri Origin Exploration Ltd. is publicly
listed on the TSX Venture Exchange under the trading symbol TOE. Tri Origin has
leveraged exposure to mineral discoveries in Australia through its 51% equity
interest in its subsidiary, Tri Origin Minerals Ltd.; a publicly traded company
listed on the Australian Stock Exchange under the symbol TRO.