Metallurgical Development Unlocks Tin System at Doradilla
Released
Released
Announcement PDF
:
•
Metallurgical Success: ~78% tin recovery achieved using a new processing approach,
producing a saleable tin concentrate from the Doradilla Tin Deposit.
•
Strategic Location & Scale: The Doradilla Tin Deposit spans a strike length of over
7.5km. It forms the south-western end of the broader 18km-long mineralised DMK Line
within SKY’s Doradilla Project, located ~45km south-east of Bourke, NSW.
•
Development Potential: These results position Doradilla as a potentially viable
development asset, complementing SKY’s flagship Tallebung Tin Project and
strengthening the Company’s longer-term growth pipeline.
•
Initial Exploration Target Defined: A maiden Exploration Target has been estimated
across 2.5km of the total 7.5km strike, incorporating SKY’s 2019 drilling, with intercepts
including:
DORC0011: 11m @ 1.04% tin from 37m, including:
5m @ 1.65% tin from 42m.1
•
Potential to triple the strike length of the initial Exploration Target with potential strike
extensions of 2.5km to the NE and 2.5km to the SW confirmed by previous SKY and other
historical drill results.
•
Next Steps: SKY is planning further drilling to build on this breakthrough and will focus
on consolidating newly uncovered data to continue advancing the Doradilla Project
alongside ongoing development of the Tallebung Tin Project.
Table 1: Doradilla Tin Deposit: Initial Exploration Target for 2.5km of the total 7.5km strike
Exploration
Target
Tonnage Range
Mt
Grade Range
Tin (%)
Contained Metal
Tin (t)
Total @ 0.20%
tin cut-off grade
10 - 15
0.32 - 0.42
32,000 - 63,000
The potential quantity and grade of the Exploration Target are conceptual in nature. As such, there has been
insufficient exploration to estimate a Mineral Resource, and it is uncertain whether further exploration will
result in a Mineral Resource. The Exploration Target has been prepared in accordance with the JORC Code 2012.
Watch a video summary of this announcement & engage with SKY here
1
Please refer to SKY ASX Announcement 10 March 2020 for further details.
SKY METALS LIMITED
+61 2 6360 1587
2 HAWTHORN PLACE, ORANGE NSW 2800
WWW.SKYMETALS.COM.AU
ABN 46 098 952 035
Sky Metals (ASX: SKY) (‘SKY’ or ‘the Company’) is pleased to advise that it has achieved a significant metallurgical
breakthrough for its 100%-owned Doradilla Tin Deposit, located within its Doradilla Project, 45km south-east of
Bourke in north-western New South Wales.
As a result of the application of a new processing approach to mineralised samples from the Doradilla Deposit,
SKY has achieved metallurgical recoveries of up to ~78% tin to a saleable cassiterite (tin-oxide) concentrate,
representing a major breakthrough in terms of the economic significance of this project within SKY’s portfolio.
In light of this processing breakthrough, SKY has completed a review of historical drilling at the Doradilla Project
and established a maiden Exploration Target for the Deposit, with demonstrable upside as indicated from both
previous drilling and historical records.
SKY Managing Director, Oliver Davies, said: “We’ve always been aware of the potential for the Doradilla Project
to host an extensive tin system, however our ability to progress this asset has been hindered by our ability to
unlock the tin through a viable metallurgical processing route. Now, through the application of a combination of
conventional gravity, magnetic and new flotation process steps, we have achieved economic recoveries of up to
78% tin.
“This is an exciting and very significant breakthrough which transforms the potential and outlook for this project.
While our primary focus remains squarely on the Tallebung Tin Project, where we are in the midst of a major
resource expansion drilling campaign, Doradilla is clearly shaping up as a sizeable and very attractive pipeline
development asset.
“Importantly, it is a complementary development opportunity from both a commodity and geographic perspective,
also being located NSW. We now see the potential for Doradilla to emerge as a second tin production hub for SKY
in north-western NSW, strengthening our growth profile and adding an important new dimension to our asset
base”
DORADILLA PROJECT (EL 6258, SKY 100%)
METALLURGICAL PROCESS TESTWORK PROGRAM
Sky Metals has successfully developed a new metallurgical processing flowsheet for the Doradilla Tin Deposit,
achieving a significant milestone in tin recovery. Recent metallurgical testwork on drill core from hole DOXD001—
originally drilled by YTC Resources in 2008—has demonstrated that approximately 78% of tin can be recovered
into a high-grade, saleable tin concentrate.
The testwork focused on the oxide zone mineralisation from DOXD001, with a sample taken from between 29.4–
38.1m depth. Initial tests focused on confirming cassiterite as the dominant tin mineral through optical mineralogy
and XRD analysis. The flowsheet developed begins with gravity separation, recovering around 55% of tin, followed
by further concentration steps that further increase grade to 45–55% tin in a saleable concentrate.
Iron contamination, which previously hindered tin flotation recovery in the -38um size range, was effectively
addressed using high intensity magnetic separation and attritioning techniques, significantly improving tin grade
and recovery. Early results suggest further optimisation could increase recovery rates even more. SKY will
continue refining the process to position Doradilla as a reliable source of tin concentrate amid growing global
demand and continued global supply challenges.
Additional analysis is underway to assess the potential recovery of rare earth elements (REE) and other potential
by-products from process materials, further enhancing the value of Doradilla’s polymetallic mineralisation. Initial
results indicate that the REE’s report to the high intensity magnetics fractions along with iron.
2
EXPLORATION TARGET BASIS
An Exploration Target has been defined for the Doradilla Tin Deposit, situated at the southwestern end of the
Doradilla–Midway–3KEL (DMK) skarn line within EL6258. The target is estimated at 10-15 million tonnes (Mt)
grading 0.32-0.42% Sn, representing a potential 32,000 to 63,000 tonnes of contained tin.
Figure 1: Plan showing the initial Exploration Taret area and the extensions to potentially triple the Exploration
Target along strike. Insert shows an image of the cassiterite (tin-oxide) (courtesy of UNSW) over 2.5km along
strike beyond the margin of the initial Exploration Target and, to the southwest, the drillholes not currently in the
SKY database. Showing that the Doradilla Tin Deposit continuous and open in all directions.
Geological Background
The Doradilla Deposit is hosted within a stratigraphically persistent calc-silicate skarn horizon, interpreted to be
part of the Devonian Cobar Supergroup. This skarn unit, up to 100m thick, is semi-continuous along the DMK line
and has been the focus of historical and recent exploration. Mineralisation is associated with greisenised and
2
Please refer to SKY ASX Announcement 4 July 2023 for further details.
3
skarn-altered zones adjacent to felsic intrusives, particularly the Midway Granite, which is considered a key
mineralising source.
Basis of the Exploration Target
The Exploration Target is based on:
• Historical drilling data from North Broken Hill Ltd, Renison Ltd, Aberfoyle Exploration Pty Ltd, and others
between 1972 and 1984 (detailed in Table 2).
• Compilation of over 94 drill collars and 5,150 assay records from SKY’s database.
• Observed mineralisation style and host geology, delineating the cassiterite-rich skarn system.
Geological domains were created in 3D modelling software Leapfrog Geo and wireframes for three (3) mineralised
horizons (H1-H3) were exported. Data was imported into Minesight software for analysis and further modelling.
Long sections of these modelled horizons are shown below in Figure 2.
Table 2: Doradilla Tin Deposit: Initial Exploration Target data summary. NB: From 2007-2014 YTC Resources
completed numerous resampling programs of historic diamond drill cores, confirming previous assaying from
past explorers and providing a broader sampled range, often identifying new zones of tin mineralisation.
Year
Company
1972
1973
North Broken Hill
North Broken Hill
1974
1977
1979
1980
1981
1983
North Broken Hill
Renison Ltd
Aberfoyle
Aberfoyle
Aberfoyle
Aberfoyle
1984
1985
2007
2008
2012
2013
Metals Exploration
Metals Exploration
YTC Resources
YTC Resources
YTC Resources
YTC Resources
2014
YTC Resources
2019
SKY Metals
Total
Total Holes
Total Metres
RAB
AC
RC
DD
RAB
16
-
-
-
4
5
3
8
3
1214
-
-
-
-
4
2
7
1
1
-
-
31
-
-
-
31
16
AC
Samples in Exploration Target
RC
DD
RAB
-
-
783.33
142.32
118.31
365.24
272.75
119
-
-
-
3
15
179
41
-
-
-
1417
62
1415.3
357.6
555.2
-
-
-
-
32
18
136
26
19
3
-
-
1845
-
-
389.2
-
-
83
-
-
18
56
96
12
6
-
-
-
641
-
-
-
96
-
6
41
1214
1845
641
11080.3
119
AC
83
RC
96
DD
651
Tin (Sn) was estimated into primary blocks using Ordinary Kriging and suitable downhole variography was
obtained which provided a useful estimate of the nugget and short range. However, for the level of estimate further
variographic analysis was not completed. As further data is added and/or further geological interpretation
completed this could be revisited later when deemed necessary to complete a Mineral Resource Estimate in
accordance with JORC Code (2012).
Density was varied in the model to reflect the oxidation state and depth of mineralisation. Densities were estimated
from drillcore density measurements via Archimedes'/immersion method to give densities on average of 3.3t/m3
for the fresh rock and 2.2/m3 for the oxide material.
4
Figure 2: Doradilla Tin Deposit: Long sections of the block model used for the initial Exploration Target with the two main mineralised skarn horizons, namely ‘H2’ and
‘H3’, shown above. Blocks are coloured by tin (Sn) grade for those estimated. NB: Low drill density at depth highlights untested potential plunge extensions.
5
Figure 3: Doradilla Tin Deposit: Cross sections of the block model used for the initial Exploration Target with the
two main mineralised skarn horizons shown, namely ‘H3’ and ‘H2’ from left to right on section, respectively.
Blocks are coloured by tin (Sn) grade for those estimated within the skarn horizons.
The target area includes both deeper sulphide mineralisation as well as shallow, oxide mineralisation with tin
grades consistent across multiple drill intercepts. Validation drilling by SKY in 2019 confirmed previous drilling
results, intercepts included:
DORC001:
11m @ 1.04% Sn from 37m, including:
5m @ 1.65% Sn from 42m.1
1
Please refer to SKY ASX Announcement 10 March 2020 for further details.
6
Next Steps
To advance the Exploration Target toward Mineral Resource classification, the following work is planned:
• Infill and step-out drilling to confirm continuity and geometry of mineralisation, particularly to follow up:
- Multiple aircore holes returning intercepts >0.5% Sn over significant widths with confirmed
cassiterite-dominate mineralisation and,
- Newly recognised historic drilling which has not been digitised into SKY’s drilling database.
• Metallurgical test work to assess tin recovery from oxide and sulphide zones to continue to build on the
excellent results achieved to date.
• Culminating in geological modelling and resource estimation in accordance with JORC Code (2012).
This announcement is authorised for release by the Board of Sky Metals Limited.
Investors:
Oliver Davies – Managing Director & CEO
+61 (0) 430 359 547
Media:
Nicholas Read – Read Corporate
+61 (0) 419 929 046
JOIN SKY METALS’ INTERACTIVE INVESTOR HUB
Visit skymetals.com.au to interact with Sky Metals’ announcements and updates
To watch a video summary of this announcement & engage with SKY click here
About the Tallebung Tin Project (100% SKY)
Tallebung stands as an open-pit, technology enabled, near-term tin development project. Tallebung is uniquely
placed to provide secure tin supply, to feed irreplaceable and rapidly expanding tin demand, essential in semiconductors, electronics and solar PV technologies.
The Tallebung Tin Project is located at the site of large-scale historical tin mining in central Western NSW
where tin was first discovered in the 1890s. SKY is progressively defining a large-scale hardrock tin resource
with recent higher-grade tin zones discovered on the margins of the known deposit and exceptional
metallurgical performance demonstrated across the entire known deposit.
The shallow, open-pit tin veins combined with the ideal nature of the tin, hosted as large, discrete grains of
simple tin-oxide (cassiterite minerals), all ideally lends itself to low-cost tin production advantages, including
exceptional X-ray based ore sorting performance, demonstrated to upgrade the tin up to 44x, prior to low-cost
gravity separation to produce a saleable tin concentrate.
7
Competent Persons Statement
The information in this report that relates to Exploration Results and the Exploration Target is based on information
compiled by Mr. Oliver Davies, who is a Member of the Australasian Institute of Geoscientists. Mr. Oliver Davies
is an employee and director of Sky Metals Ltd and has sufficient experience which is 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 2012 Edition of the ‘Australasian Code for Reporting of Exploration Results,
Mineral Resources and Ore Reserves.’ Mr. Davies consents to the inclusion in this report of the matters based on
his information in the form and context in which it appears.
The information in this report that relates to Metallurgical Results is based on information compiled by Michael
Gunn, who is a Fellow of the Australasian Institute of Mining and Metallurgy. Michael Gunn is a contractor of Sky
Metals Ltd and has sufficient experience which is 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 2012
Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. Mr
Gunn consents to the inclusion in this report of the matters based on his information in the form and context in
which it appears.
Previously Reported Information
The information in this report that references previously reported exploration results is extracted from the
Company’s ASX market announcements released on the date noted in the body of the text where that reference
appears. The previous market announcements are available to view on the Company's website or on the ASX
website (www.asx.com.au). The Company confirms that it is not aware of any new information or data that
materially affects the information included in the original market announcements. The Company confirms that the
form and context in which the Competent Person’s findings are presented have not been materially modified from
the original market announcements.
Disclaimer
This report contains certain forward-looking statements and forecasts, including possible or assumed reserves
and resources, production levels and rates, costs, prices, future performance or potential growth of Sky Metals
Ltd, industry growth or other trend projections. Such statements are not a guarantee of future performance and
involve unknown risks and uncertainties, as well as other factors which are beyond the control of Sky Metals Ltd.
Actual results and developments may differ materially from those expressed or implied by these forward-looking
statements depending on a variety of factors. Nothing in this report should be construed as either an offer to sell
or a solicitation of an offer to buy or sell securities.
This document has been prepared in accordance with the requirements of Australian securities laws, which may
differ from the requirements of United States and other country securities laws. Unless otherwise indicated, all
ore reserve and mineral resource estimates included or incorporated by reference in this document have been,
and will be, prepared in accordance with the JORC classification system of the Australasian Institute of Mining,
and Metallurgy and Australian Institute of Geoscientists.
Table 1: Doradilla Project – Drillhole details for metallurgical sample.
Hole ID
Easting
(MGA)
Northing
(MGA)
RL (m)
DIP
Azimuth
(MGA)
Total Depth
(m)
Comment
DOXD001
434145
6641818
146
-70
321
92.9
29.4–38.1m sampled for metallurgical testing.
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JORC CODE, 2012 - TABLE 1
Section 1 Sampling Techniques and Data – DORADILLA PROJECT
(Criteria in this section apply to all succeeding sections)
Criteria
Sampling techniques
Explanation
•
Commentary
Nature and quality of sampling (e.g. cut channels, random chips, or specific specialised industry SKY Metals: RC Drilling – the total sample (~20-30kg) is delivered via cyclone into a large plastic bag
standard measurement tools appropriate to the minerals under investigation, such as downhole which is retained for future use if required. 1m intervals are split using a cone splitter on the rig into a
separate calico at the time of drilling.
gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as
limiting the broad meaning of sampling.
Previous work: core/sample recovery has been recorded in many cases and it appears that efforts were
made to maximise recovery and therefore sample representivity. Details of sampling procedures for
earlier holes are limited but it is assumed that ‘industry standard’ methods of the time were employed.
Available details are reported in subsequent sections.
SKY and YTC Resources resampled and assayed a number of interval of 1970s and 1980s core available in
the Londonderry Drillcore Library, part of the W B Clarke Geoscience Centre, western Sydney. These new
assays supersede any old assays in the Exploration Target.
•
Include reference to measures taken to ensure sample representivity and the appropriate
calibration of any measurement tools or systems used.
SKY Metals: For RC drilling, assay standards or blanks are inserted at least every 50 samples.
All sample lab received weights show consistency with recovery and interval length.
Review of past drilling reporting show evidence of Sample intervals and preparation following standard
industry practice and review of available drill core has confirmed this.
•
Aspects of the determination of mineralisation that are Material to the Public Report. In cases SKY Metals: Each sample was dried, crushed and pulverised as per standard industry practice.
where ‘industry standard’ work has been done this would be relatively simple (e.g. ‘reverse
circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a RC Drilling – the total sample (~20-30kg) is delivered via cyclone into a large plastic bag which is retained
30 g charge for fire assay’). In other cases, more explanation may be required, such as where
for future use if required. 1m intervals are split using a cone splitter on the rig into a separate calico at
there is coarse gold that has inherent sampling problems. Unusual Commodities or
the time of drilling. Where mineralisation has not been logged, 4m Composites have been made by using
mineralisation types (e.g. submarine nodules) may warrant disclosure of detailed information. a spear to Combine equal amounts of samples from each 1m calico.
The primary metal of interest, tin (Sn) and also tungsten (W) were determined by lithium borate fusion
XRF (method ALS – ME-MS85) – considered appropriate for these elements. Multielement assaying was
Completed for 48 elements by 0.25g four-acid digest with ICPMS determination (method ALS – MEMS61)
Drill core sampling is by sawn half or quarter core PQ, HQ, NQ or BQ core. Nominal sample intervals are
1m with a range from 0.3m to 2.0m. Early drilling was completed in imperial units with conversions by
SKY and YTC Resources.
Drilling techniques
•
SKY Metals: Reverse circulation (RC) drilling using 110mm rods, 144mm face sampling hammer.
Drill type (e.g. core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka,
sonic, etc) and details (e.g. core diameter, triple or standard tube, depth of diamond tails, faceHistoric drilling completed with RAB, AC and HQ/NQ/BQ diamond core drilling.
sampling bit or other type, whether core is oriented and if so, by what method, etc)
Drill sample recovery
•
Method of recording and assessing core and chip sample recoveries and results assessed.
9
SKY Metals: RC drilling - high capacity RC rig was used to enable dry samples collected. Drill cyclone is
Criteria
Explanation
•
•
Commentary
Measures taken to maximise sample recovery and ensure representative nature of the samples. cleaned between rod changes and after each hole to minimise cross-hole contamination.
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
Sample weights are recorded for each sample. Recoveries were generally excellent and consistent,
however, if samples were wet the recoveries were less consistent.
There is no known relationship between sample recovery and grade. Where samples recoveries are less
than 95% there is no relationship observed between grade and sample recovery. Relationships between
sample recovery and grade are not considered significant where recoveries exceeded 95% in fresh rock.
DD holes were typically drilled as NQ/BQ size core for older holes. It is assumed that earlier DD holes
were drilled with a standard core barrel. SKY completed core orientation where possible but there are no
records of core orientation for older holes. Confirmed with inspection of historic core.
Logging
•
•
•
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
The total length and percentage of the relevant intersections logged
Systematic geological and geotechnical logging was undertaken when the holes were originally drilled.
Data collected includes:
•
Nature and extent of lithologies.
•
Relationship between lithologies.
•
Amount and mode of occurrence of ore minerals.
•
Location, extent, and nature of structures such as bedding, cleavage, veins, faults etc.
Structural data (alpha & beta) are recorded for orientated core.
Geotechnical data such as recovery, RQD, fracture frequency, qualitative IRS, microfractures, veinlets and
number of defect sets. For some geotechnical holes the orientation, nature of defects and defect fill are
recorded.
Both qualitative and quantitative data is collected.
RC chips, half or quarter core (BQ/NQ/HQ) & ¾ core (PQ) samples are retained in trays for future
reference.
Sub-sampling techniques
and sample preparation
•
•
•
•
•
•
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
SKY Metals: RC drilling - the total sample (~20-30kg) is delivered via cyclone into a large plastic bag which
is retained for future use if required. 1m intervals are split using a cone splitter on the rig into a separate
calico at the time of drilling. Where 4m Composites have been made, a spear is used to split equal
amounts of each metre into the 4m Composite.
Samples were dried crushed and pulverised to 90% passing 75 microns. This is considered to
appropriately homogenise the sample to allow subsampling for the various assay techniques.
SKY: Certified Reference Material (CRM) and blanks were inserted at least every 50 samples to assess the
accuracy and reproducibility of the drill core results. The results of the standards were to be within ±10%
variance from known certified result. If greater than 10% variance the standard and up to 10 samples
each side were re-assayed. SGS conducted internal check samples every 20 for multielement assay.
RC drilling - duplicate samples are collected of re-split intervals. Duplicates generally show excellent
repeatability.
10
Criteria
Explanation
Commentary
Sample sizes are industry standard and considered appropriate
Few details of sub-sampling techniques and sample preparation are available for the earlier DD holes. It
is assumed that ‘industry standard’ procedures of the time were applied and confirmed with later core
inspection.
Quality of assay data
and laboratory tests
•
•
•
The nature, quality and appropriateness of the assaying and laboratory procedures used and
SKY Metals: Standard assay procedures performed by a reputable assay lab, (ALS), were undertaken.
whether the technique is considered partial or total
Forty-eight elements Ag, As, Cu, Fe, Pb, S, Zn are digested by four-acid digest then analysed by ICPMS
For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in
(method ME-MS61).
determining the analysis including instrument make and model, reading times, calibrations
factors applied and their derivation, etc
Sn and W assays were generated by lithium borate fusion XRF (method ME-MS85) – considered
Nature of quality control procedures adopted (e.g. standards, blanks, duplicates, external
appropriate for these elements.
laboratory checks) and whether acceptable levels of accuracy (i.e. lack of bias) and precision have
been established
No geophysical tools were used in the determination of assay results.
Certified reference material or blanks were inserted at least every 50 samples. Standards are purchased
from Certified Reference Material manufacture Companies: Standards were purchased in foil lined
packets of between 60g and 100g. Different reference materials were used to cover high grade, medium
grade, low grade, and trace ranges of elements, with a primary focus on Sn and Cu.
Fusion XRF was used for the earlier DD holes and is considered best practice for assaying of Sn and W.
Few details are available for the assay procedures for the historic holes, however, inspection and
reassays of the drillcore aligns with the assays received.
Verification of sampling •
and assaying
•
•
•
SKY Metals: Drill data is Compiled and collated and reviewed by senior staff. External consultants do not
The verification of significant intersections by either independent or alternative Company
routinely verify exploration data until resource estimation procedures are deemed necessary. The
personnel.
intersection calculations were viewed by >1 geological personnel.
The use of twinned holes.
Documentation of primary data, data entry procedures, data verification, data storage (physical
Twinned holes have been used by past explorers to validate the results achieved and have confirmed
and electronic) protocols.
these historic results.
Discuss any adjustment to assay data
Drill Hole Data including: meta data, any gear left in the drill hole, lithological, mineral, survey, sampling,
magnetic susceptibility was collected and stored as physical and electronic copies or entered directly into
an excel spread sheet using drop down codes. When Complete the spreadsheet was Combined into a
master excel spreadsheet as the drill hole database.
Assay data was provided by ALS via .csv spreadsheets. The data was validated using the results received
from the known certified reference material. Hard copies of the assay certificates were stored with drill
hole data such as drillers plods, invoices, and hole planning documents.
Assay data is not adjusted.
Earlier drilling: There is no documentation available relating to the verification of significant intersections
by either independent or alternative company personnel. However, it seems unlikely that significant
intersections were not verified by alternative personnel at the time.
All primary data was sourced from historical records, either physical or electronic. Records of historical
data entry procedures, data verification and data protocols are lacking.
11
Criteria
Explanation
Commentary
There is no evidence of any adjustments to historical assay data.
Location of data points
•
•
•
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
SKY Metals: Historic drill hole collars were located using either a licenced surveyor or on a local imperial
or metric grid. Conversion of the local grid co-ordinates has been undertaken by previous exploration
Companies. SKY has used DGPS surveying of drillholes (± 0.1m) to accurately locate them.
All coordinates are based on Map Grid Australia Zone 55E, Geodetic Datum of Australia 1994.
Earlier drilling: historic drill hole collars were located using either a licenced surveyor or on a local
imperial or metric grid. SKY has used DGPS surveying of drillholes (± 0.1m) to accurately locate them, or
handheld GPS (+/-3m). Where handheld GPS has been used, SKY will DGPS them at a later date.
Data spacing and
distribution
•
•
•
Data spacing for reporting of
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