35% Increase of JORC Resource Upgrade at Mpokoto Gold Project
Armadale Capital Plc
Armadale Capital Plc / Index: AIM / Epic: ACP / Sector: Investment
Company
19 December 2013
Armadale Capital Plc (‘Armadale’ or ‘the Company’)
35% Increase of JORC Resource Upgrade at Mpokoto Gold Project
Armadale, the AIM quoted investment company focused on natural resource
projects in Africa, is pleased to announce an updated JORC Code
Compliant Resource estimate at the Mpokoto Gold Project in the Katanga
Province in the south of the Democratic Republic of Congo (‘Mpokoto’ or
‘the Project’).
Highlights:
-
35% increase in total Mineral Resource to 510,000oz gold (‘Au’) from
11.2 million tonnes (‘Mt’) @ 1.42g/t Au at a cut-off grade of 0.5g/t
(previous resource of 380,000oz Au from 7.2Mt @ 1.65g/t at a 0.5g/t
cut-off)
-
65% of the updated Mineral Resource is in the Indicated category
-
The Mineral Resource estimate is based upon the completion of an
additional 21 diamond drill holes completed since the last resource
estimate, a recent re-interpretation of the geology from164 holes
drilled for a total of 18,142m –conducted by previous owners of the
project
-
Considerable further upside potential left– Exploration Target of
10Mt-15Mt at 1.2g/t-1.5g/t Au, as reviewed by CSA
-
Defined development strategy to rapidly advance the Project through to
low Capex, low Opex gold production in 24 months
Justin Lewis, Director of Armadale, said, “I am delighted to announce
this 35% increase in the total gold Mineral Resource estimate at
Mpokoto, demonstrating the Board’s belief that the Project has
considerable further scope to become a highly attractive pre-production
gold asset. The updated Mineral Resource is based on additional drilling
and an increased level of confidence in the geological and resource
model work that was conducted on behalf of the group. Our activities
remain focused on the further delineation of gold resource ounces,
together with the additional critical development work required ahead of
low cost commercial gold production targeted within the next two years.â€
Further Information
CSA Global Pty Ltd (‘CSA’) was engaged to complete a Mineral Resource
estimate (‘MRE’) for gold mineralisation in the Mpokoto Gold Project
where the group has the right to earn an 80% interest in the Project.
The MRE is based on the results obtained from 164 drill holes (18,142m),
consisting of 57 reverse circulation (‘RC’) totaling 3,585m, and 107
diamond drill holes (incl. RC holes with diamond core tails) totaling
14,557m, and is classified as Indicated and Inferred. This is based on
confidence in the geological interpretation and continuity from the
results of the drilling campaign and surface mapping. The results of the
estimate are tabulated in Table 1 below.
Table 1: Mineral Resource estimate results for Mpokoto. Au >= 0.5g/t
Weathering
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Classification
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Tonnes
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Au g/t
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Ounces
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Oxide
|
|
Measured
|
|
-
|
|
-
|
|
-
|
|
|
Indicated
|
|
250,000
|
|
1.46
|
|
11,700
|
|
|
Sub-total
|
|
250,000
|
|
1.46
|
|
11,700
|
|
|
Inferred
|
|
240,000
|
|
1.17
|
|
8,900
|
|
|
Total
|
|
490,000
|
|
1.32
|
|
20,600
|
|
Transitional
|
|
Measured
|
|
-
|
|
-
|
|
-
|
|
|
Indicated
|
|
870,000
|
|
1.50
|
|
42,200
|
|
|
Sub-total
|
|
870,000
|
|
1.50
|
|
42,200
|
|
|
Inferred
|
|
1,120,000
|
|
1.07
|
|
38,200
|
|
|
Total
|
|
1,990,000
|
|
1.26
|
|
80,400
|
|
Fresh
|
|
Measured
|
|
-
|
|
-
|
|
-
|
|
|
Indicated
|
|
5,970,000
|
|
1.46
|
|
280,200
|
|
|
Sub-total
|
|
5,970,000
|
|
1.46
|
|
280,200
|
|
|
Inferred
|
|
2,750,000
|
|
1.46
|
|
129,000
|
|
|
Total
|
|
8,720,000
|
|
1.46
|
|
409,200
|
|
All
|
|
Grand Total
|
|
11,200,000
|
|
1.42
|
|
510,200
|
|
Note: The Mineral Resource was estimated within constraining
wireframe solids based on geological interpretations and / or a lower Au
limit of 0.2 g/t. Results are reported from blocks with a block grade of
>= 0.5 g/t Au. Differences may occur due to rounding
Mineral Resource Estimation (MRE)
The classified mineralisation model is based on drill spacing which was
nominally on 40m sections although drilling directions in places
deviated away from the drilling section line.
The deposit has been separated into four areas, defined by intensity of
drilling and changes in strike of mineralisation. The classified Mineral
Resource is confined to Areas 3 and 4, with the other two areas lacking
sufficient drilling to define a Mineral Resource (a map showing the
drill hole locations can be found on the Company’s website at www.armadalecapitalplc.com).
Wireframe solids were generated based on geological interpretations from
CSA Global, based upon lithological domains and a lower cut-off grade of
>= 0.2g/t Au. A north-south fault has been interpreted to offset the
mineralisation across strike between Areas 3 and 4..
Limited drilling in Area 3 (Inferred Mineral Resource) has resulted in a
strike continuous mineralisation model which may be broken up following
results from any subsequent drilling. Depth extents of the
mineralisation model are limited to approximately 50m down dip of the
deepest drill hole intercept, unless drill holes along strike allow the
interpretation to continue at depth without drill support on the current
section. Strike extent of mineralisation is limited to approximately
half the sectional spacing beyond the drill hole limits.
The MRE consists of 12 zones of Au mineralisation and two weathering
domains (oxide and fresh). Mineralisation domains were encapsulated by
means of 3D wireframed envelopes. Domains were extrapolated along strike
or down plunge to half section spacing or if a barren hole cut the
plunge extension before this limit.
Strike extent of the mineralisation model in Area 4 is approximately
750m, plan width of the lenses and intervening waste zones pinches and
swells between 100m and 200m, vertical depth of approximately 200m.
Mineralisation generally outcrops at surface.
Strike extent of the mineralisation model in Area 3 is approximately
900m, plan width of the lens 6m, vertical depth ranges from 40m to 90m.
Mineralisation generally outcrops at surface. Grade was interpolated
into the block model using ordinary kriging. Density values of 2.2t/m3
(Oxide zone) and 2.72t/m3 (fresh zone) were assigned to the
block model and used to calculate tonnages as reported in Table 1.
Classification of the Mineral Resource estimates was carried out taking
into account the geological understanding of the deposit, QAQC of the
samples, density data and drill hole spacing. The Indicated Mineral
Resources were based upon a higher level of confidence than the Inferred
resources, whereby geological and grade continuity are assumed, but not
confirmed. All available data was assessed and the competent person’s
relative confidence in the data was used to assist in the classification
of the Mineral Resource. The current classification assignment
appropriately reflects the Competent Person’s view of the deposit.
Geology and Mineralisation
Mineralisation occurs in tabular and laterally extensive stratigraphic
horizons within a sedimentary sequence which consists of gold rich
coarse-grained sandstone horizons interlayered with fine to very coarse
layered siliciclastic units overlying metamorphic schistose basement
forming a broad south southwest and west dipping re-folded fold limb,
that was targeted during several drilling programs. The modelling was
constrained within wireframe solids representing the interpreted
geological limits of the gold mineralised sandstone units. The
mineralisation in Area 4 consists of several parallel stacked lenses
that are open down dip.
About Mpokoto Gold Project
Mpokoto is located in the western part of the Katanga Province
approximately 250km west of Kolwezi in the Democratic Republic of Congo,
and approximately 25km from the Zambian border. The area is highly
prospective, with local operators including Ivanplats Limited and
Glencore Plc.
Since 1998, approximately US$20 million was spent on gold exploration at
the Project. In 2012, mining consultancy TetraTech completed a Mineral
Resource estimation reported according to the JORC 2004 and NI 43-101
guidelines. At a cut-off of 0.5g/t Au the deposit was estimated to
contain 7.2Mt at 1.6g/t Au for approximately 380,000oz Au. Of this,
approximately 5.3Mt at 1.6g/t Au are classified in the Indicated
category for 290,000oz Au.
This estimate includes a portion of the previously reported Exploration
Target which has been tested through recent drilling and converted to an
Inferred Mineral Resource (Area 3). CSA have reviewed the Exploration
Target which now consists of between 10 and 15Mt at 1.2g/t-1.5g/t Au.
The quantity and grade of the Exploration Target is conceptual and there
has been insufficient exploration to define a Mineral Resource.
The potential for additional resources and reserves is strong. Should
this target mineralisation be converted to Inferred and Indicated
resources and then to reserves, it is likely that the Project throughput
rate can be substantially upgraded. Resource delineation drilling
programmes are planned to test the target potential.
Competent Person Statement:
Scientific or technical information in this release has been prepared by
Dr Simon Dorling Phd (geol) MAIG, Principal Consultant, and Mr. David
Williams BSc (Hons) MAusIMM MAIG, Principal Consultant, of CSA Global
Pty Ltd. Dr Simon Dorling and David Williams are members of the
Australian Institute of Geoscientists (MAIG) and each has over 20 years’
experience, which is relevant to the style of mineralisation under
consideration and to the activity which they are undertaking to qualify
as Competent Persons, as defined in the 2012 Edition of the
“Australasian Code for Reporting of Exploration Results, Mineral
Resources and Ore Reserves†(the JORC Code). Dr Simon Dorling and Mr.
David Williams consent to the inclusion in this report of the
information, in the form and context in which it appears.
A copy of the announcement, which includes a map and drawings relating
to Mpokoto’s location and geology, can be found on the Company’s website
at www.armadalecapitalplc.com.
**ENDS**
Enquiries:
Company
Justin Lewis, Director +61 439 162369
Charles Zorab +44 207 233 1462
Nomad and broker: finnCap Limited
Stuart Andrews/ Christopher Raggett +44 207 220 0500
Press relations: St Brides Media & Finance Ltd.
Susie Geliher/Charlotte Heap +44 207 236 1177
More information can
be found on the website www.armadalecapitalplc.com
Notes
Armadale Capital Plc is focussed on investing in and developing a
portfolio of investments, targeting the natural resources and/or
infrastructure sectors. The Company, led by a team with operational
experience and a strong track record in Africa, has a strategy of
identifying high growth potential businesses where it can take an active
role in their advancement.
Armadale holds the right to an 80% interest in the Mpokoto Gold Project
in the Democratic Republic of Congo. Armadale are focused on proving up
the resource potential of Mpokoto with a view to commencing commercial
gold production in 2015.
Armadale also holds approximately a 40% interest in Mine Restoration
Investments Ltd, a South African listed company, which aims to develop
profitable operations within the South African mining industry through
its coal briquetting operation in KwaZulu Natal and acid mine drainage
technology in the Witwatersrand basins.
In addition, Armadale has a small portfolio of listed investments which
are focused on gold production and exploration. The Directors continue
to maintain an active acquisition strategy and will review investment
opportunities that they believe have the potential to be accretive in
terms of shareholder value.
JORC Code, 2012 Edition
JORC Code, 2012 Edition – Table 1 report template
Section 1 Sampling Techniques and Data
(Criteria in this section apply to all succeeding sections.)
Criteria
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JORC Code explanation
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Commentary
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Sampling techniques
|
|
-
Nature and quality of sampling (eg cut channels, random
chips, or specific specialised industry standard measurement
tools appropriate to the minerals under investigation, such as
down hole gamma sondes, or handheld XRF instruments, etc). These
examples should not be taken as limiting the broad meaning of
sampling.
-
Include reference to measures taken to ensure sample
representivity and the appropriate calibration of any
measurement tools or systems used.
-
Aspects of the determination of mineralisation that are
Material to the Public Report.
-
In cases where ‘industry standard’ work has been done this
would be relatively simple (eg ‘reverse circulation drilling was
used to obtain 1 m samples from which 3 kg was pulverised to
produce a 30 g charge for fire assay’). In other cases more
explanation may be required, such as where there is coarse gold
that has inherent sampling problems. Unusual commodities or
mineralisation types (eg submarine nodules) may warrant
disclosure of detailed information.
|
|
-
The deposit was sampled using both Diamond and Reverse
Circulation (RC) drill holes over three drilling campaigns.
Drill holes were generally drilled 50-100m apart. A total of 78
Diamond holes and 77 RC holes were drilled for a total of
18,151m (12,842m diamond; 5309m RC). The majority of the holes
were drilled towards the northeast with dips varying between -50
and -60º.
-
RC samples were collected at 1m by riffle splitter. Diamond core
provided Netcom with high quality samples. Appropriate QAQC
protocols were followed, including submission of field
duplicates and insertion of commercial standards
-
Diamond core in ore was NQ size, sampled every 1m in the ore
zone, cut into half, whereas RC samples were obtained by 1m
samples from the rig. Preliminary samples from both Diamond and
RC programmes were crushed and ground to obtain a representative
fraction of greater than 500g. This fraction was then dried to
constant mass at 105ºC. The representative fraction was ground
to 90% passing 100 micron using a laboratory mill. The samples
were weighed. and mixed with a 12:22 Lithium Metaborate/Lithium
Tetraborate Flux containing 4% Lithium Nitrate as an oxidising
agent. The flux/sample mixture was then fused at 1050ºC. All
elements were determined by X-ray Fluorescence Spectrometry
(XRF). LOI was determined gravimetrically in a muffle furnace at
1000ºC.
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Drilling techniques
|
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Drill type (eg core, reverse circulation, open-hole hammer,
rotary air blast, auger, Bangka, sonic, etc) and details (eg
core diameter, triple or standard tube, depth of diamond tails,
face-sampling bit or other type, whether core is oriented and if
so, by what method, etc).
|
|
-
Diamond drilling comprises HQ sized core. Drilling involved
coring to the end of hole. Hole depths range from ~0 to 454m.
Core was oriented using single shot orientation tool. RC
drilling comprised a nominal 5 ½ inch diameter face sampling
hammer. Hole depths range from 0m to 150m.
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Drill sample recovery
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Method of recording and assessing core and chip sample
recoveries and results assessed.
-
Measures taken to maximise sample recovery and ensure
representative nature of the samples.
-
Whether a relationship exists between sample recovery and
grade and whether sample bias may have occurred due to
preferential loss/gain of fine/coarse material.
|
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-
Diamond core recovery is logged and recorded in the database.
Between 10 to 20% core loss was recorded over parts of the oxide
zone. RC recovery was visually assessed and considered to be
acceptable within the mineralized zones.
-
Diamond core was reconstructed into continuous runs for
orientation marking, depths being checked against the depth
marked on the core blocks. RC samples were visually checked for
recovery, moisture and contamination. A cyclone and splitter
were used to provide a uniform sample and these were routinely
cleaned.
-
Sample Recovery is generally very high within the ore zone. No
significant bias is expected, and any potential bias is not
considered material at this stage of resource development.
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Logging
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-
Whether core and chip samples have been geologically and
geotechnically logged to a level of detail to support
appropriate Mineral Resource estimation, mining studies and
metallurgical studies.
-
Whether logging is qualitative or quantitative in nature.
Core (or costean, channel, etc) photography.
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The total length and percentage of the relevant intersections
logged.
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Diamond core and RC drill chips underwent detailed logging
through the entire hole (at 1m intervals for RC chips), with
record kept of colour, lithology, degree of oxidation, water
table etc. Diamond core was geotechnically logged for recovery
and RQD. Information on structure type and orientation are
recorded in the database. Diamond core and RC Chip trays have
been stored in Kasenge site for future reference.
-
Diamond core and RC chip logging included records of lithology,
oxidation state, colour, mineralisation, alteration and veining.
Core was photographed in both dry and wet form.
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Sub-sampling techniques and sample preparation
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-
If core, whether cut or sawn and whether quarter, half or all
core taken.
-
If non-core, whether riffled, tube sampled, rotary split, etc
and whether sampled wet or dry.
-
For all sample types, the nature, quality and appropriateness
of the sample preparation technique.
-
Quality control procedures adopted for all sub-sampling
stages to maximise representivity of samples.
-
Measures taken to ensure that the sampling is representative
of the in situ material collected, including for instance
results for field duplicate/second-half sampling.
-
Whether sample sizes are appropriate to the grain size of the
material being sampled.
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-
Diamond core was sawn in half.
-
RC samples were collected on the rig using riffle splitters.
Samples were generally dry.
-
Samples were riffle split to obtain a representative fraction of
>500g.Samples were then dried and ground to 90% passing 100
microns using laboratory mills for XRF analysis.
-
Field QAQC procedures included the insertion of field duplicates
and commercial standards for DD and RC sampling Standards were
inserted at a rate of very 19th and 20th
sample.
-
RC field duplicates were taken from 1m cone split samples at the
rig. Diamond holes were sampled at 1m intervals for raw assays
samples.
-
Sample sizes are considered to be appropriate to accurately
represent the Au mineralisation at Mpokoto based on the
thickness and consistency of the intersections, the sampling
methodology and the percent value assay ranges for the primary
elements.
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Quality of assay data and laboratory tests
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The nature, quality and appropriateness of the assaying and
laboratory procedures used and whether the technique is
considered partial or total.
-
For geophysical tools, spectrometers, handheld XRF
instruments, etc, the parameters used in determining the
analysis including instrument make and model, reading times,
calibrations factors applied and their derivation, etc.
-
Nature of quality control procedures adopted (eg standards,
blanks, duplicates, external laboratory checks) and whether
acceptable levels of accuracy (ie lack of bias) and precision
have been established.
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The gold analysis was done at the ALS laboratory in S.A. by fire
assay which is industry standard for gold. Results provide the
total contained amount of gold in the samples.
-
Not applicable to the project.
-
Field data were all recorded on hardcopies (geological logging,
sampling intervals, etc.) using a set of standard Excel
templates, then manually entered into Excel spreadsheets. Data
were then sent to Mrs. O. Schuh for validation. Assay files were
sent to Mrs. O. Schuh upon receipt from the laboratories.
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Verification of sampling and assaying
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-
The verification of significant intersections by either
independent or alternative company personnel.
-
The use of twinned holes.
-
Documentation of primary data, data entry procedures, data
verification, data storage (physical and electronic) protocols.
-
Discuss any adjustment to assay data.
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Several different company personnel visually verified
intersections in both diamond core and RC chips.
-
No Twinned hole was used during any of the programmes.
-
Field data were all recorded on hardcopies (geological logging,
sampling intervals, etc.) using a set of standard Excel
templates, then manually entered into Excel spreadsheets. Data
were then sent to Mrs. O. Schuh for validation. Assay files were
sent to Mrs. O; Schuh upon receipt from the laboratories.
-
No adjustments were made, other than for values below the assay
detection limit which have been entered as the negative of the
detection limit.
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Location of data points
|
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-
Accuracy and quality of surveys used to locate drill holes
(collar and down-hole surveys), trenches, mine workings and
other locations used in Mineral Resource estimation.
-
-
Specification of the grid system used.
-
Quality and adequacy of topographic control.
|
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Drill hole collars were surveyed by differential GPS with
horizontal accuracies of about 0.1m. A downhole survey point was
taken every 50m by means of a single shot camera tool by the
drilling contractor.
-
The grid system is WGS_UTM84 Zone 32
-
The topographic surface has been generated from 2m topographic
contours obtained during a topographic survey completed in 2013
by SD Géomatique. All collar locations have been picked up by
means of differential GPS.
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Data spacing and distribution
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|
-
Data spacing for reporting of Exploration Results.
-
Whether the data spacing and distribution is sufficient to
establish the degree of geological and grade continuity
appropriate for the Mineral Resource and Ore Reserve estimation
procedure(s) and classifications applied.
-
Whether sample compositing has been applied.
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-
Drill holes were generally drilled 10-100m apart in the area of
the classified resource.
-
The data spacing and distribution is sufficient to demonstrate
spatial and grade continuity of the mineralised horizon to
support the definition of Inferred and Indicated Mineral
Resources under the 2012 JORC code.
-
No composite have been applied for Diamond and RC drilling.
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Orientation of data in relation to geological structure
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-
Whether the orientation of sampling achieves unbiased
sampling of possible structures and the extent to which this is
known, considering the deposit type.
-
If the relationship between the drilling orientation and the
orientation of key mineralised structures is considered to have
introduced a sampling bias, this should be assessed and reported
if material.
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Drilling sections are orientated Northeast - to Southwest with
respect to geographic north. This orientation is perpendicular
to the strike of the host-meta-sediment strata units observed at
Mpokoto. The majority of the drilling is angled to the
Northeast, dipping between -50 and -60º to return mineralisation
intervals with thickness as true as possible. Diamond core
observation confirmed the pertinence of this hole orientation.
-
Diamond drilling confirmed that drilling orientation did not
introduce any bias regarding the orientation of the gold
mineralisation unit.
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Sample security
|
|
-
The measures taken to ensure sample security.
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Chain of Custody was managed by the various owners of the
project. Samples were stored on site and delivered to the assay
laboratory in Johannesburg by DHL and by transporter Palma sprl
of Lubumbashi (DRC). Samples submission sheets were in place to
track the progress of every batches of samples.
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Audits or reviews
|
|
-
The results of any audits or reviews of sampling techniques
and data.
|
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-
Sampling techniques are consistent with industry standards.
Consistency of data was validated by Mrs. O; Schuh while loading
into the database (Depth from < Depth to; interval is within
hole depth, check for overlapping samples or intervals, etc.).
Any data which fails the database constraints and cannot be
loaded is returned to field crew for validation, etc.). Global
consistency was also checked later on by plotting sections using
the database and reconciling assays against geology.
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Section 2 Reporting of Exploration Results
(Criteria listed in the preceding section also apply to this section.)
Criteria
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JORC Code explanation
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Commentary
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Mineral tenement and land tenure status
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|
-
Type, reference name/number, location and ownership including
agreements or material issues with third parties such as joint
ventures, partnerships, overriding royalties, native title
interests, historical sites, wilderness or national park and
environmental settings.
-
The security of the tenure held at the time of reporting
along with any known impediments to obtaining a licence to
operate in the area.
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The deposit is located in exploration licence PE12897. Netcom
Global Inc has the right to acquire an 80% interest in Kisenge
Limited's Mpokoto Gold project
-
The tenement is in good standing with no known impediment to
future grant of a mining lease
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Exploration done by other parties
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Acknowledgment and appraisal of exploration by other parties.
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The tenement has been explored for Au in the past. The project
was established by Cluff Mining Limited in 1998, Goldfields
acquired Kisenge Limited from Cluff Mining in 2003 and sold to
Casa in 2007.
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Geology
|
|
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Deposit type, geological setting and style of mineralisation.
|
|
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The Mpokoto gold mineralisation occurs in a stratified
low-metamorpic siliciclastic sedimentary sequence resting on
metamorphosed basement of Proterozoic age. The mineralisation
occurs stratiform and occurs preferentially in coarse-sandy
facies.
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Drill hole Information
|
|
-
A summary of all information material to the understanding of
the exploration results including a tabulation of the following
information for all Material drill holes:
-
easting and northing of the drill hole collar
-
elevation or RL (Reduced Level – elevation above sea
level in metres) of the drill hole collar
-
dip and azimuth of the hole
-
down hole length and interception depth
-
hole length.
-
If the exclusion of this information is justified on the
basis that the information is not Material and this exclusion
does not detract from the understanding of the report, the
Competent Person should clearly explain why this is the case.
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-
This material has been adequately reported in previous
announcements.
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Data aggregation methods
|
|
-
In reporting Exploration Results, weighting averaging
techniques, maximum and/or minimum grade truncations (eg cutting
of high grades) and cut-off grades are usually Material and
should be stated.
-
Where aggregate intercepts incorporate short lengths of high
grade results and longer lengths of low grade results, the
procedure used for such aggregation should be stated and some
typical examples of such aggregations should be shown in detail.
-
The assumptions used for any reporting of metal equivalent
values should be clearly stated.
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-
Not reporting exploration results.
-
Not applicable
-
Not applicable
|
|
Relationship between mineralisation widths and intercept lengths
|
|
-
These relationships are particularly important in the
reporting of Exploration Results.
-
If the geometry of the mineralisation with respect to the
drill hole angle is known, its nature should be reported.
-
If it is not known and only the down hole lengths are
reported, there should be a clear statement to this effect (eg
‘down hole length, true width not known’).
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Drill hole angles of between -50â° and -60â° toward the northeast
are adequate to drill the moderately dipping to south west units.
-
Not reporting exploration results.
-
Not reporting exploration results.
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Diagrams
|
|
-
Appropriate maps and sections (with scales) and tabulations
of intercepts should be included for any significant discovery
being reported These should include, but not be limited to a
plan view of drill hole collar locations and appropriate
sectional views.
|
|
-
Refer to diagrams in body of text
|
|
Balanced reporting
|
|
-
Where comprehensive reporting of all Exploration Results is
not practicable, representative reporting of both low and high
grades and/or widths should be practiced to avoid misleading
reporting of Exploration Results.
|
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Not reporting exploration results.
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Other substantive exploration data
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Other exploration data, if meaningful and material, should be
reported including (but not limited to): geological
observations; geophysical survey results; geochemical survey
results; bulk samples – size and method of treatment;
metallurgical test results; bulk density, groundwater,
geotechnical and rock characteristics; potential deleterious or
contaminating substances.
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Surface sampling and mapping were completed over different field
campaigns by Cluff, Goldfields and CASA. Jigsaw Geoscience was
contracted to complete detailed mapping of the project. An
aeromagnetic survey of the project was completed in 2005 giving
further insight over the geometry of deformed host units.
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Further work
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The nature and scale of planned further work (eg tests for
lateral extensions or depth extensions or large-scale step-out
drilling).
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Diagrams clearly highlighting the areas of possible
extensions, including the main geological interpretations and
future drilling areas, provided this information is not
commercially sensitive.
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Metallurgical test work will be completed on recently drilled
resource area. Some more DD drilling is planned in untested
areas to upgrade the resource, reduce spacing and test
mineralisation extensions.
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Refer to diagrams in body of text
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Section 3 Estimation and Reporting of Mineral Resources
(Criteria listed in section 1, and where relevant in section 2, also
apply to this section.)
Criteria
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JORC Code explanation
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Commentary
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Database integrity
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Measures taken to ensure that data has not been corrupted by,
for example, transcription or keying errors, between its initial
collection and its use for Mineral Resource estimation purposes.
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Data validation procedures used.
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Data used in the Mineral Resource estimate is sourced from a
data base dump, provided in the form of an MS Access database.
Relevant tables from the data base are exported to MS Excel
format and converted to csv format for import into Datamine
Studio 3 software for use in the Mineral Resource estimate.
Validation protocols for the data entered to the Data Shed
database are described in Section 1.
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Datamine has inbuilt and operator coded drill hole validation
features that test for overlapping sample intervals, differences
between collar elevations and the adjacent DTM elevation, down
hole survey readings with significant deviations over nominated
down hole intervals. Drill holes were loaded into 3D space and
visually checked for any obvious errors in survey measurements.
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Site visits
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Comment on any site visits undertaken by the Competent Person
and the outcome of those visits.
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If no site visits have been undertaken indicate why this is
the case.
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The geological Competent Person (CP) has not visited site prior
to this resource estimation due to time constraints. Plans have
been made for a site visit in early 2014. The CP has extensive
experience in sediment-hosted and orogenic gold deposits and has
a strong structural background to be able to evaluate and
interpret the deposit geology and mineralisation data based on
his experience.
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Geological interpretation
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Confidence in (or conversely, the uncertainty of ) the
geological interpretation of the mineral deposit.
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Nature of the data used and of any assumptions made.
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The effect, if any, of alternative interpretations on Mineral
Resource estimation.
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The use of geology in guiding and controlling Mineral
Resource estimation.
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The factors affecting continuity both of grade and geology.
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A geological model was constructed based upon measured and
observed structural and lithological data. The Competent Person
has high confidence in the geological interpretation supporting
the Mineral Resource.
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21 diamond drill holes were completed in the past two years to
complement the pre-existing 63 diamond holes and 77 RC holes.
Drill hole logs, samples and assays, plus surface geological
outcrop mapping form the basis of the geological interpretation.
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Previous Mineral Resource estimates (x2) were based upon
geological interpretations with much less underlying geological
factual support. The interpretations generally used the same
strike and dips for the geological models as the current Mineral
Resource model.
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Lithological logs of the conglomerates hosting the
mineralisation controlled the widths and extents of the
mineralisation envelopes.
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Mineralisation occurs in tabular and laterally extensive
stratigraphic horizons. A north-south fault has been observed in
drill core and outcrop cutting the mineralisation along strike
between Areas 3 and 4. Limited drilling in Area 3 (Inferred
Mineral Resource) has resulted in a strike continuous
mineralisation model which may be broken up following results
from any subsequent drilling. Depth extents of the
mineralisation model are limited to approximately 50m down dip
of the deepest drillhole intercept, unless drill holes along
strike allow the interpretation to continue at depth without
drill support on the current section. Strike extent of
mineralisation is limited to approximately half the sectional
spacing beyond the drill hole limits.
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Dimensions
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The extent and variability of the Mineral Resource expressed
as length (along strike or otherwise), plan width, and depth
below surface to the upper and lower limits of the Mineral
Resource.
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Strike extent of the mineralisation model in Area 4 is
approximately 750m, plan width of the lenses and intervening
waste zones pinches and swells between 100m and 200m, vertical
depth of approximately 200m. Mineralisation generally outcrops
at surface.
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Strike extent of the mineralisation model in Area 3 is
approximately 900m, plan width of the lens 6m, vertical depth
ranges from 40m to 90m. Mineralisation generally outcrops at
surface.
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Estimation and modelling techniques
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The nature and appropriateness of the estimation technique(s)
applied and key assumptions, including treatment of extreme
grade values, domaining, interpolation parameters and maximum
distance of extrapolation from data points. If a computer
assisted estimation method was chosen include a description of
computer software and parameters used.
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The availability of check estimates, previous estimates
and/or mine production records and whether the Mineral Resource
estimate takes appropriate account of such data.
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The assumptions made regarding recovery of by-products.
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Estimation of deleterious elements or other non-grade
variables of economic significance (eg sulphur for acid mine
drainage characterisation).
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In the case of block model interpolation, the block size in
relation to the average sample spacing and the search employed.
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Any assumptions behind modelling of selective mining units.
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Any assumptions about correlation between variables.
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Description of how the geological interpretation was used to
control the resource estimates.
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Discussion of basis for using or not using grade cutting or
capping.
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The process of validation, the checking process used, the
comparison of model data to drill hole data, and use of
reconciliation data if available.
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CAE Studio 3 (Datamine) software was used for all geological
modelling, block modelling, grade interpolation, MRE
classification and reporting. GeoAccess Professional and Snowden
Supervisor were used for geostatistical analyses of data. The Au
interpretation was based upon a lower cut-off of 0.2g/t Au and a
lithological envelope (conglomerates). The MRE consists of 12
zones of Au mineralisation and two weathering domains (oxide and
fresh). Mineralisation domains were encapsulated by means of 3D
wireframed envelopes. Domains were extrapolated along strike or
down plunge to half a section spacing or if a barren hole cut
the plunge extension before this limit.
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Top cuts were used to constrain extreme grade values. A top cut
was set to 20g/t. All samples in Area 4 were composited to 1m
intervals, whilst drill hole data in Area 3 were composited to
2m intervals, based upon raw drill hole sample lengths. All
drill hole data (RC and Diamond) were utilised in the grade
interpolation.
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A block model was constructed using all mineralisation domains
and weathering profiles, capped by a topographical DTM. Block
sizes of 20m (X) by 20m (Y) by 10m (Z) were selected based upon
typical drill hole spacing (40m along strike). The model was not
rotated.
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Grade estimation was by Ordinary Kriging (OK) with Inverse
Distance Squared (IDS) estimation concurrently run as a check
estimate. A minimum of 12 and maximum of 40 samples were used in
any one block estimate. A maximum of 4 composited samples per
drill hole were used in any one block estimate. Cell
Discretisation of 5 x 5 x 5 was used. Grade interpolation was
run within the individual mineralisation domains, acting as hard
boundaries. Weathering profiles were used as soft boundaries and
did not control grade interpolation.
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The grade model was validated by 1) creating slices of the model
and comparing to drill holes on the same slice; 2) swath plots
comparing average block grades with average sample grades on
nominated easting, northing and RL slices; and 3) mean grades
per domain for estimated blocks and flagged drill hole samples.
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The current Mineral Resource was checked against the previously
reported Mineral Resources and shown to be of an increased
tonnage but similar grade.
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No by products were modelled.
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No selective mining units were assumed in this model.
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Only Au was modelled therefore no correlation between other
variables was required.
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Moisture
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Whether the tonnages are estimated on a dry basis or with
natural moisture, and the method of determination of the
moisture content.
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Tonnages are estimated on a dry basis.
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Cut-off parameters
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The basis of the adopted cut-off grade(s) or quality
parameters applied.
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The reporting cut-off grade of 0.5g/t was selected due to it
being the same cut-off used to report previous Mineral Resources.
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Mining factors or assumptions
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Assumptions made regarding possible mining methods, minimum
mining dimensions and internal (or, if applicable, external)
mining dilution. It is always necessary as part of the process
of determining reasonable prospects for eventual economic
extraction to consider potential mining methods, but the
assumptions made regarding mining methods and parameters when
estimating Mineral Resources may not always be rigorous. Where
this is the case, this should be reported with an explanation of
the basis of the mining assumptions made.
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It is assumed the deposit, if mined, will be developed using
open pit mining methods. No assumptions have been made to date
regarding minimum mining widths or dilution.
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Metallurgical factors or assumptions
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The basis for assumptions or predictions regarding
metallurgical amenability. It is always necessary as part of the
process of determining reasonable prospects for eventual
economic extraction to consider potential metallurgical methods,
but the assumptions regarding metallurgical treatment processes
and parameters made when reporting Mineral Resources may not
always be rigorous. Where this is the case, this should be
reported with an explanation of the basis of the metallurgical
assumptions made.
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Metallurgical test work since 2010 suggest the oxide
mineralisation is amenable to cyanidation with good gold
recoveries on CIL bottle roll tests. Recent test work has
indicated heap leach as a potential processing route for
achieving acceptable gold recoveries of up to 86%.
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Metallurgical test work since 2010 suggest the transition zone
mineralisation is amenable to cyanidation with reasonable gold
recoveries on CIL bottle roll tests. Recent test work has
indicated heap leach as a potential processing route for
achieving acceptable gold recoveries of up to 60%.
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Sulphide mineralisation metallurgical test work has suggested
that CIL gold recoveries are at 51%. It has been recommended by
previous workers that a heap leach based processing flowsheet
with an appropriate sulphide mineralisation pre-treatment method
(such as bio-heap leach) may be a processing method.
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No detailed metallurgical test work has been completed to date
on the project.
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Environmental factors or assumptions
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Assumptions made regarding possible waste and process residue
disposal options. It is always necessary as part of the process
of determining reasonable prospects for eventual economic
extraction to consider the potential environmental impacts of
the mining and processing operation. While at this stage the
determination of potential environmental impacts, particularly
for a greenfields project, may not always be well advanced, the
status of early consideration of these potential environmental
impacts should be reported. Where these aspects have not been
considered this should be reported with an explanation of the
environmental assumptions made.
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No environmental baseline studies have been completed to date on
this project.
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The project area’s topography consists of gentle hills and
valleys, with elevation ranging between 900m and 1200m.
Vegetation is mainly indigenous savannah, open woodland,
grassland plains and minor agricultural plots. Several rivers
flow through the project area.
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The climate in the project’s region is tropical to sub-tropical
with an annual rainfall of up to 1500mm.
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The topography around the Mpokoto deposit has space for
potential tailings storage areas, waste disposal, heap leach
pads and processing plants.
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Bulk density
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Whether assumed or determined. If assumed, the basis for the
assumptions. If determined, the method used, whether wet or dry,
the frequency of the measurements, the nature, size and
representativeness of the samples.
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The bulk density for bulk material must have been measured by
methods that adequately account for void spaces (vugs, porosity,
etc), moisture and differences between rock and alteration zones
within the deposit.
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Discuss assumptions for bulk density estimates used in the
evaluation process of the different materials.
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Density measurements were taken from diamond drill core, for
which there are no detailed records regarding method of
measurement. It is assumed the measurements were taken using
conventional wet immersion techniques (weight in air, weight in
water). No information available regarding any coating of core
prior to immersion.
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Density values were added to drill hole file and statistical
analyses conducted based upon weathering profiles. Only the
Fresh rock domain yielded results with an appropriate sample
support, for a density value of 2.72t/m3. Oxide and
Transitional zones were applied a nominal (assumed) density of
2.2t/m3.
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Classification
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The basis for the classification of the Mineral Resources
into varying confidence categories.
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Whether appropriate account has been taken of all relevant
factors (ie relative confidence in tonnage/grade estimations,
reliability of input data, confidence in continuity of geology
and metal values, quality, quantity and distribution of the
data).
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Whether the result appropriately reflects the Competent
Person’s view of the deposit.
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Classification of the Mineral Resource estimates was carried out
taking into account the geological understanding of the deposit,
QAQC of the samples, density data and drill hole spacing. The
Indicated Mineral Resources were based upon a higher level of
confidence than the Inferred resources, whereby geological and
grade continuity are assumed, but not confirmed.
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All available data was assessed and the competent persons
relative confidence in the data was used to assist in the
classification of the Mineral Resource.
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The current classification assignment appropriately reflects the
Competent Person’s view of the deposit.
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Audits or reviews
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The results of any audits or reviews of Mineral Resource
estimates.
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No audits or review of the Mineral Resource has been carried out
to this time.
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Discussion of relative accuracy/ confidence
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Where appropriate a statement of the relative accuracy and
confidence level in the Mineral Resource estimate using an
approach or procedure deemed appropriate by the Competent
Person. For example, the application of statistical or
geostatistical procedures to quantify the relative accuracy of
the resource within stated confidence limits, or, if such an
approach is not deemed appropriate, a qualitative discussion of
the factors that could affect the relative accuracy and
confidence of the estimate.
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The statement should specify whether it relates to global or
local estimates, and, if local, state the relevant tonnages,
which should be relevant to technical and economic evaluation.
Documentation should include assumptions made and the procedures
used.
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These statements of relative accuracy and confidence of the
estimate should be compared with production data, where
available.
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An inverse distance estimation algorithm was used in parallel
with the ordinary Kriged interpolation, with results very
similar to the Kriged results.
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No other estimation method or geostatistical analysis has been
performed.
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The Mineral Resource is a local estimate, whereby the drill hole
data was geologically domained above a nominated Au cut-off
grade, resulting in fewer drill hole samples to interpolate the
block model than the complete drill hole dataset, which would
comprise a global estimate.
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Relevant tonnages and grade above a nominated cut-off grade are
provided in the introduction and body of this report. Tonnages
were calculated by filtering all blocks above the cut-off grade
and sub-setting the resultant data into bins for weathering and
classification. The volumes of all the collated blocks were
multiplied by the dry density value to derive the tonnages. The
gold metal value (g) for each block was calculated by
multiplying the Au grade (g/t) by the block tonnage. The total
sum of all metal (g) for the deposit for the filtered blocks was
divided by the total tonnage to derive the reportable Au grade
(g/t).
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No production data is available to reconcile results with.
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