
FOR
IMMEDIATE RELEASE:
March 6, 2008
WOODLAWN ZINC-COPPER PROJECTS UPDATE
??
Tri
Origin Exploration Ltd. (TOE:TSX-V) is pleased to report
that???s its 51% - owned Australian subsidiary?? Tri Origin Minerals Ltd (???TRO???) has
released an update on the progress of the Bankabable Feasibility Study (???BFS???)
being conducted on the Woodlawn Zinc-Copper Projects at Woodlawn, NSW.?? Woodlawn,
located 200 km west of Sydney, contains a previously reported 8.58 million
tonne Measured and Indicated underground resource as well as a 6.98 million
tonne Measured and Indicated?? resource of surface tailings which provide the
basis for two complimentary feasibility studies; the Woodlawn Retreatment
Project (???WRP???) and the Woodlawn Underground Project (???WUP???) which are being
assessed for an integrated project development.
TRO???s Woodlawn update as
reported to the Australian Securities Exchange is as follows:?? ??
??
KEY
POINTS:
- Feasibility Study of WRP is progressing well and on target for
completion in early April 2008. Annual production of 60,000 tonnes of
copper and zinc concentrates expected;
- ???Feasibility Study of a staged development involving an incremental
expansion of the WRP processing facility to treat ore mined from the WUP
is on target for completion in May 2008. Total annual production of
120,000 to 140,000 tonnes of concentrate would be expected from an
integrated WRP/WUP operation;
- ???Data from a December 2007 drilling programme is being used to
calculate a resource for the North Tailings Dam which is expected to confirm
an upgrade to the existing 6.98 Mt of Resources for the WRP already
outlined at the West and South Tailings Dams;
- Deep drilling in the vicinity of old underground workings has
provided data to confirm the underground resource model survey data and
provide samples for metallurgical confirmatory testing;
??
UPDATE
ON THE WOODLAWN ZINC-COPPER PROJECTS (???WZP???) FEASIBILITY STUDY
Following the completion
of a Preliminary Feasibility Study of the WZP, a decision was taken in April
2007 to start work on a Bankable Feasibility Study (???BFS???) with the aim of
completing the study by the first quarter of 2008. The initial intent of the
BFS was to study the feasibility of a stand-alone WUP which involved reopening
the Woodlawn underground mine to access high grade mineralisation that remained
when the operation ceased in 1998. Since then, the scope of the study was
expanded to also evaluate the feasibility of a stand-alone WRP involving
recovering and reprocessing the tailings that were produced from the previous
Woodlawn open cut and underground operations.????
The WUP study envisages a
relatively high grade, low production rate scenario, involving higher capital
and unit operating costs while the WRP study envisages a higher volume,
relatively low grade operation with relatively lower unit operating and capital
costs.??
The respective
stand-alone studies have now progressed to a point where consideration is being
given to a staged development scenario which commences with the development of
a stand-alone tailings retreatment project followed by an incremental expansion
into a fully integrated processing operation that treats both tailings and ore
extracted by an underground mining operation.?? The integrated project
development scenario is expected to:
??
?????????????????? - ?????????? introduce
a desired level of flexibility into the operation;
?????????????????? - ?????????? provide
a more capital efficient approach to project development than would be ?????????????????? ?????????????????????? ?????????????????? possible
with two stand-alone operations; and
?????????????????? - ?????????? achieve
certain unit operating cost advantages, particularly with the underground ?????????????? ?????????????????????? ?????????????????? project.
The stand-alone WRP
feasibility study is scheduled for completion in early April 2008 and is
expected to demonstrate the feasibility of the tailings retreatment operation
producing approximately 60,000 tonnes of copper and zinc concentrates per year.
The study of the integrated project involving both the tailings retreatment and
an underground mining and processing operation will be finalized in May 2008.
This study is expected to demonstrate the feasibility of an operation producing
up to 80,000 tonnes of concentrates per year from underground ore giving total
project output of between 120,000 to 140,000 tonnes of concentrates per year.
Completion of economic
evaluation, project permitting, and metallurgical test work for the WUP are all
on the critical path for a development decision for the integrated WZP.
Potential
Upgrade of WRP Resources
In relation to the WRP,
estimation of the resource contained in North Tailings Dam has commenced
following the receipt of assays of samples acquired in the December 2007
drilling programme. Grades are in line with expectations and based on reported
grades and information from previous operators of the Woodlawn operations, the
North Tailings Dam resource appears likely to be in the order of 2.0 Mt with
similar average grades to the 8.6 Mt of Measured, Indicated and Inferred
Resources contained in the South and West tailings dams.??
The results of this work
will not change the WRP plant design but will enable the North Dam resource to
be considered in an overall production schedule which will result in an
extension to the tailing retreatment project life of approximately 1.5 years.
Confirmation
of WUP Resources
Two diamond drilling rigs
are currently operating on Tri Origin???s Woodlawn tenements.
One of the rigs has until
recently been deployed performing geotechnical drilling for the proposed new
decline to access the existing underground workings. This drilling rig has now
completed its assigned task and has been moved to the nearby site of the Cowley
Hills Prospect. The second drill rig has been used to obtain additional diamond
core sample for confirmatory metallurgical test work for the WUP resource
calculation and in this respect has completed Hole WLTD004 and wedge WLTD004B
and is currently drilling Hole WLTD005.??
Hole
WLTD004
The drilling of Hole
WLTD004 has validated the accuracy and confidence of the underground resource
model survey data in this area as well as provided samples for confirmatory
metallurgical test work.
Hole WLTD004 successfully
intersected mineralization associated with the C2 and C lenses, which were
partly mined by previous operators. The C2 Lens is a subsidiary copper rich
lens located approximately 25 m into the hanging wall of the much larger C
Lens. Presented below in Table 1 are assays of C2 Lens intercepts from Holes
WLTD004 and WLTD004B and an intercept of the C Lens by Wedge WLTD004B.
Table 1:
C2 and C Lens Assays ??? Hole WLTRD004
Hole
|
Lens
|
From
(m)
|
To
(m)
|
Interval
(m)
|
Cu
(%)
|
Pb
(%)
|
Zn
(%)
|
Ag
(ppm)
|
Au
(ppm)
|
WLTD004
WLTD004B
WLT004B
Incl.
|
C2
C2
C
|
383.00
398.50
438.90
442.00
|
389.80
406.60
446.20
446.20
|
6.80
8.10
7.30
4.20
|
2.79
2.92
1.66
1.89
|
0.10
0.07
4.87
7.18
|
0.85
0.38
12.34
19.60
|
12
13
171
201
|
0.16
0.22
2.32
2.27
|
The intercepts in the C2
Lens are approximately 10 m vertically apart. The true width of the C2 Lens at
the drilled locations is approximately 5 to 7 m.
Mineralisation associated
with the C Lens was intersected from 438.9 m to 446.2 m. The true width of the
intercepts in C Lens is approximately 90% of the intervals shown in Table 1.
This zone is associated with a large remnant pillar and is located
approximately 400 m below surface. The C Lens was the largest individual lens
mined at Woodlawn and constitutes approximately 35% of the current underground
resource.??
Mineralisation in this
zone is dominated by massive sulphides containing pyrite, sphalerite, galena
and chalcopyrite. Assays indicate lower grade base metals mineralisation
followed by ??4.2 m of high grade zinc rich mineralization. Gold and silver values
for the intercept are elevated compared to average resource grades. Unfortunately
the hole intersected the edge of a stope and had to be abandoned at 446.2 m.
However, high grade zinc mineralisation was predicted for a further 12 m -15 m
beyond the end of this hole.
Importantly, the
analytical results presented above for both the C2 and C lenses confirm Tri Origin???s
modelling of the resource and grade distribution of the mineralisation.
Hole
WLTD005
Further metallurgical
samples for confirmatory test work are being obtained by drilling Hole WLTD005 through
remnant pillars in the A and B1 Lenses. Immediately adjacent to Hole WLTD005
are historical holes W057 and U174 drilled by previous operators which intersected
high grade mineralization within the A and B1 lenses. The assay results from
these holes are shown below in Table 2.
TABLE 2:
Historical Assay Results Adjacent To Hole WLTD005
Hole
|
Lens
|
From
(m)
|
To
(m)
|
Interval
(m)
|
ETW
(m)
|
Cu
(%)
|
Pb
(%)
|
Zn
(%)
|
Ag
(ppm)
|
Au
(ppm)
|
W057
U174*
U174*
|
A
B1
B1
|
362.7
95.5
120
|
377.9
120
133
|
15.2
24.5
13.0
|
12
16
7
|
1.2
0.7
3.5
|
6.2
5.6
0.2
|
16.6
10.8
0.7
|
121
95
17
|
0.1
0.5
0.1
|
*?? ??Underground
drillhole, ETW = Estimated True Width
Hole WLTD005 is scheduled
to be completed in the near future and assay results will be reported when
available.
The
information in this report that relates to Exploration Results and Mineral
Resources is based on information compiled by Mr David Hobby, an employee of TRO,
who is a Member of The Australasian Institute of Mining and Metallurgy. Mr
Hobby has sufficient experience which is relevant to the style of
mineralisation and type of deposit under consideration and to the activities
which he is undertaking to qualify as a Competent Person as defined in the 2004
Edition of the ???Australasian Code for Reporting of Exploration Results, Mineral
Resources and Ore Reserves???. Mr Hobby consents to the inclusion in the report
of the matters in the form and context in which they appear based on
information derived from his technical work.
This
release was prepared by Tri Origin Exploration Ltd. (???TOE???) 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 Securities Exchange under the
symbol TRO.