Further Priority Targets for Nickel Copper & Gold Identified
Released
Released
Announcement PDF
ASX ANNOUNCEMENT
Date: 19 February 2014
ASX: IPT
Number: 338/190214
FURTHER PRIORITY TARGETS FOR NICKEL, COPPER AND GOLD
IDENTIFIED AT MULGA TANK, WA
12 targets for nickel-copper and copper-gold identified in soil geochemistry survey.
3 targets open along strike. Large areas not yet sampled.
Follow up work programmes being planned.
Twelve (12) new priority target areas for nickel-copper and copper-gold deposits have been
identified by Impact Minerals Limited (ASX:IPT) in previous soil geochemistry data covering a part
of the very poorly explored Mulga Tank Project in the Minigwal greenstone belt, 200 km north east of
Kalgoorlie in W.A. (Figure 1 and 2).
The targets, each of which covers several square kilometres, were identified in a review of a broad
spaced ionic leach soil geochemistry survey covering the central part of the 425 sq km project area
(Figure 2).
Six of the targets occur on the west side of the project area, along strike and adjacent to the Mulga
Tank Dunite where Impact recently discovered significant nickel and copper mineralisation under
about 50 m of transported cover in its maiden drill programme on E39/988 (Impact 20% and earning
70% from Golden Cross Resources Limited) (Figure 2). Drill intercepts included:
114.8 m at 0.3% nickel from 98 m including 2 m at 1.3% nickel; and 0.5 m at
1.2% nickel from 211 m; and 0.6 m at 0.7% nickel from 181 m in Hole MTD011; and
0.75 m at 0.85% nickel, 0.35% copper and 0.24 g/t PGE and 6.7 m at 0.5% nickel in
Hole MTD004 (Figure 3 and see announcement 29 January 2014).
The mineralisation, which occurs over an area of at least 15 sq km, occurs below elevated nickel-in-soil
and copper-in-soil values. This suggests that nickel and copper ions are migrating to the surface
through the transported cover and are detected by the ionic leach soil geochemistry technique, which is
proprietary to ALS Global Laboratories.
Some of the strongest soil responses, up to 2,670 ppb nickel and 4,830 ppb copper and 4.5 ppb gold
occur in the north west corner of E39/988 (Figure 2). These values are significantly elevated above the
regional background values for these metals. The anomalies are open to the north west along a 10 km
strike extent of the greenstone belt within the project area that has not been soil sampled.
The six other targets occur on the east side of the project area and indicate significant potential for
copper and gold mineralisation (Figure 2). There has been limited aircore drilling in some of these
areas and data from this work is currently being compiled.
309 Newcastle Street Northbridge Western Australia 6003
Tel +61 (8) 6454 6666 Facsimile +61 (8) 6454 6667
Email info@impactminerals.com.au www.impactminerals.com.au
The soil samples were mostly taken at a very wide spacing of 400 m between samples with infill
samples taken at 200 m intervals in places. This is a very coarse sample spacing compared to that
commonly used in nickel sulphide exploration. Infill soil survey programmes and further surveys
along strike in areas not yet sampled are warranted.
A programme and budget for the next phase of work at Mulga Tank is being prepared.
ABOUT THE MULGA TANK PROJECT
Impact’s Mulga Tank Project comprises 13 exploration licences covering 425 km² of the Minigwal
greenstone belt and surrounding area in the eastern part of the Yilgarn Craton (Figure 4).
Exploration Model for Mulga Tank: Perseverance and Rocky’s Reward
The Mulga Tank Project is prospective for nickel (and copper) sulphide deposits similar to the
Perseverance (45 Mt at 2% nickel) and Rocky’s Reward (9.6 Mt at 2.4% Nickel) mines near Leinster in
Western Australia (Figures 1 and 5). The Mulga Tank Dunite is also very similar to the unit that
hosts the Perseverance nickel deposit as well as the host unit to the Mount Keith disseminated nickel
deposit that contains more than 2 million tonnes of nickel metal. The geology of the area indicates
that the prospective basal unit of the Mulga Tank Dunite is preserved over a 12 sq km area and has
not been explored. In addition there are many 10’s of kilometres of strike of other ultramafic units
throughout the Minigwal greenstone belt that have also not been drilled. Some of these units are
associated with significant nickel-copper-precious metal-in-soil anomalies.
Impact has discovered three different styles of high tenor nickel and copper mineralisation within
and surrounding the Mulga Tank Dunite:
1. Extensive disseminated nickel sulphide within the Mulga Tank Dunite, for example at the
SGA Propect;
2. High tenor nickel and copper in veins at the base of the Mulga Tank Dunite, for example at
the Conductor 2 Prospect. This is very encouraging and demonstrates significant potential for
the discovery of a major massive sulphide deposit along many strike kilometres of this very
prospective contact;
3. High tenor nickel sulphide in multiple komatiites in a flow channel, for example at the
Conductor 1 Prospect. Such channels are an important control on nickel sulphide
mineralisation at major nickel mines such as Rocky’s Reward, Kambalda and Forrestania in
W.A.
Significant drill intercepts are shown in Figure 3. Impact’s work, together with the results from
previous explorers drill holes, demonstrates that the Mulga Tank Dunite contains nickel sulphides in
multiple horizons over a very large area of many square kilometres.
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Summary of the licence ownership at the Mulga Tank Project
Of the 13 licences in the Mulga Tank Project, Impact:
owns 100% of six licences (E39/1632 and E39/1633 with another four under application);
owns 20% of E39/988, with Golden Cross 80%. Impact has the right to earn a further 50% from
Golden Cross to move to 70% ownership;
owns 25% of E39/1072, with Golden Cross 75%. Impact has the right to earn a further 50%
from Golden Cross to move to 75% ownership; and
is earning a 50% interest from Golden Cross in five other licences - E39/1439, E39/1440,
E39/1441, E39/1442 and E39/1513 (Figure 5).
A further $1.1 million must be spent by Impact before November 2017 to complete the earn-in from
Golden Cross.
Dr Michael G Jones
Managing Director
The review of exploration activities and results contained in this report is based on information compiled by Dr Mike Jones, a Member of
the Australian Institute of Geoscientists. He is a director of the company and works for Impact Minerals Limited. He has sufficient
experience which is relevant to the style of mineralisation and types of deposits 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 (the JORC Code). Mike Jones has consented to the inclusion in the report of the matters
based on his information in the form and context in which it appears.
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Figure 1. Location of Impact’s Mulga Tank Project and significant nickel sulphide mines
and prospects including Perseverance and Rocky’s Reward deposits with new nickelcopper-PGE discoveries in the emerging nickel-copper province to the east.
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Figure 2. Image of magnetic data over the Mulga Tank Project showing the location of the
new targets identified in the soil geochemistry data.
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Conductor 3
0.25 m at 3.8% Ni, 0.7% Cu 0.7 g/t PGE
59 m at 0.3% Ni
Conductor 1
0.75 m at 0.85% Ni 0.15% Cu
6.7 m at 0.5% Ni
Conductor 2
0.3 m at 0.7% Ni
21 m at 0.4% Ni
Conductor 5
SGA Propsect
1 m at 2% Ni
0.5 m at 1.2% Ni
115 m at 0.3% Ni
Conductor 4
Figure 3. Image of the Total Magnetic Intensity from airborne magnetic data over the
Mulga Tank Dunite (white outline) showing:
1. the location and modelled geometry of the five EM targets drilled;
2. best assay results;
3. the nickel-in-soil geochemistry contours at greater than 800 ppb; and
4. the copper in soil geochemistry contour at greater than 3,000 ppb to the south
west coincident with Conductor 4.
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Figure 4. Tenement ownership at the Mulga Tank Project.
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Figure 5. Conceptual cross-section for the Mulga Tank Dunite and surrounding area
showing the Perseverance and Rocky’s Reward exploration model.
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APPENDIX 1 - SECTION 1 SAMPLING TECHNIQUES AND DATA
Criteria
JORC Code explanation
Sampling techniques
Nature and quality of sampling (e.g. 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.
The soil samples were taken at a depth of 15 – 20 cm below surface and sieved to -2mm mesh
size. The targets at Mulga Tank have been drilled by Reverse Circulation (RC) and diamond drill
holes (DD). Eight holes for 3,025 m were completed.
A hand held Olympus XRF machine was used to take multi-element readings on the samples bags
from the RC drill pre-collars (I reading every I metre) and at 25 cm to 50 cm intervals on the
diamond core. These readings are a guide only and do not constitute an accurate or precise
assay. Impact has conducted a number of quality control experiments to determine the optimal
reading time and number of readings per sample site. A correlation of these readings against the
assay data suggests that at values greater than 1% nickel, the XRF analyser gives a good
approximation to the chemical assay value.
Drill holes were oriented to intersect the dip of electromagnetic conductors as interpreted by
Impact’s consultants Newexco.
Include reference to measures taken to ensure sample representivity and the
appropriate calibration of any measurement tools or systems used
RC samples have been collected by riffle splitter. Diamond core was used to obtain high quality
samples that were logged for lithological, structural, alteration and other attributes. Sampling
was carried out under Impact Minerals Ltd protocols and QAQC procedures as per industry best
practice.
A combination of mapping, soil geochemistry, airborne magnetic data and ground EM surveys
identified the Mulga Tank target.
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 (e.g. ‘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 (e.g. submarine nodules) may warrant disclosure of
detailed information
Diamond core is mostly NQ2 size, sampled on geological intervals cut into half core to give
sample weights under 3 kg. Reverse circulation drilling was used to obtain 1 m samples from
which 3 kg was pulverised. Samples were crushed, dried and pulverised (total prep) to produce a
sub-sample for analysis by four acid digest with an ICP/OES finish for base metals and lead
collection fire assay with AAS finish for precious metals.
The main sulphide types are expected to be pentlandite and chalcopyrite, with pyrite, and minor
sphalerite. Non-sulphide nickel species in weathered and transitional material have not yet been
identified.
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, face-sampling bit or other type, whether core is
oriented and if so, by what method, etc).
Diamond drilling accounts for 75 % of the drilling and comprises HQ and NQ2 sized core. Precollar depths range from 50 m to about 150 m and hole depths range from 300 m to 570 m. The
core was oriented using a down-hole orientation tool at the end of every run with 70% of
orientations rated as “good”.
RC drilling in the pre-collar accounts for 20 % of the total drilling and comprises 140 mm diameter
face sampling hammer drilling.
Method of recording and assessing core and chip sample recoveries and
results assessed
Diamond core and RC recoveries are logged and recorded in the database. Overall recoveries are
>95% for Mulga Tank and there are no core loss issues or significant sample recovery problems.
Drilling techniques
Drill sample recovery
Commentary
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Criteria
Logging
Sub-sampling techniques and
sample preparation
JORC Code explanation
Commentary
Measures taken to maximise sample recovery and ensure representative
nature of the samples
Diamond core at Mulga Tank is reconstructed into continuous runs on an angle iron cradle for
orientation marking. Depths are checked against the depth given on the core blocks and rod
counts are routinely carried out by the drillers. RC samples were visually checked for recovery,
moisture and 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.
No sample bias has been established because an insufficient number of samples have been
assayed.
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.
Information on structure type, dip, dip direction, alpha angle, beta angle, texture, shape and fill
material is stored in the structure table of the database.
Whether logging is qualitative or quantitative in nature. Core (or costean,
channel, etc) photography.
Logging of diamond core and RC samples at Mulga Tank recorded lithology, mineralogy,
mineralisation, structural (DDH only), weathering, colour and other features of the samples. Core
was photographed in both dry and wet form.
The total length and percentage of the relevant intersections logged
All drillholes were logged in full, apart from rock roller diamond hole pre-collar intervals of
between about 50 m and 70 m depth.
If core, whether cut or sawn and whether quarter, half or all core taken.
Core for Mulga Tank was cut in half onsite using an automatic core saw. All samples were
collected from the same side of the core.
If non-core, whether riffled, tube sampled, rotary split, etc and whether
sampled wet or dry.
RC samples were split using a riffle splitter.
For all sample types, the nature, quality and appropriateness of the sample
preparation technique.
The sample preparation of diamond core for Mulga Tank follows industry best practice in sample
preparation involving oven drying, coarse crushing of the half core sample down to ~10 mm
followed by pulverisation of the entire sample (total prep) using Essa LM5 grinding mills to a grind
size of 85% passing 75 micron. The sample preparation for RC samples is identical, without the
coarse crush stage.
Quality control procedures adopted for all sub-sampling stages to maximise
representivity of samples.
Field QC procedures involve the use of certified reference material as assay standards, along with
blanks, duplicates and barren washes. The insertion rate of these averaged 1:50.
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.
Field duplicates are done every 50 samples.
Whether sample sizes are appropriate to the grain size of the material being
sampled.
The sample sizes are considered to be appropriate to correctly represent the sulphide
mineralisation at Mulga Tank based on the disseminated style of mineralisation, the thickness
and consistency of the intersections, the sampling methodology and percent value assay ranges
for the primary elements.
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Criteria
Quality of assay data and
laboratory tests
Verification of sampling and
assaying
JORC Code explanation
Commentary
The nature, quality and appropriateness of the assaying and laboratory
procedures used and whether the technique is considered partial or total.
See optiro. An industry standard fire assay technique using lead collection with an Atomic
Absorption Spectrometry (AAS) finish was used for Au, Ag, Pt, Pd.
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.
No geophysical tools were used to determine material element concentrations.
Nature of quality control procedures adopted (e.g. standards, blanks,
duplicates, external laboratory checks) and whether acceptable levels of
accuracy (i.e. lack of bias) and precision have been established.
Quality control procedures for assays are as per Impact Minerals protocols. Accuracy and
precision are within acceptable limits.
The verification of significant intersections by either independent or
alternative company personnel.
Significant intersections have yet to be returned and therefore verification is not required.
The use of twinned holes.
No twin holes have been drilled at Mulga Tank.
Documentation of primary data, data entry procedures, data verification, data
storage (physical and electronic) protocols.
Primary data was collected using a set of standard Excel templates on Toughbook laptop
computers using lookup codes. The information was sent to IOGlobal/Reflex for validation and
compilation into a SQL database server.
Discuss any adjustment to assay data.
Location of data points
Data spacing and distribution
Orientation of data in relation to
geological structure
Accuracy and quality of surveys used to locate drillholes (collar and down-hole
surveys), trenches, mine workings and other locations used in Mineral
Resource estimation.
Drill holes and soil sample sites were located by hand held GPS.
Down-hole surveys used single shot readings have been completed during drilling at least at 50 m
intervals.
Specification of the grid system used.
The grid system for Mulga Tank is MGA_GDA94, Zone 51.
Quality and adequacy of topographic control.
Standard government topographic maps and hand held GPS have been used for topographic
control. The land surface is flat and increased accuracy and precision for topographic contours is
not required at this stage.
Data spacing for reporting of Exploration Results.
This is a first pass reconnaissance drill programme designed to test geochemical and geophysical
anomalies. Drill spacing is adequate for that and will change according to on-going 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.
This is a first pass reconnaissance drill programme designed to test geochemical and geophysical
anomalies. Drill spacing is adequate for that and will change according to on-going results.
Whether sample compositing has been applied.
Samples will be composited to one metre lengths and adjusted where necessary to ensure that
no residual sample lengths have been excluded (best fit).
Whether the orientation of sampling achieves unbiased sampling of possible
structures and the extent to which this is known, considering the deposit type.
The targets have been drilled sub-perpendicular to mineralisation within the stratigraphy, but
subparallel to the orientation of some veins in the mineralised trend. Structural logging based on
oriented core to determine the controls on mineralisation are on-going.
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Criteria
JORC Code explanation
Commentary
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.
No orientation based sampling bias has been identified at Mulga Tank in the data at this point,
although the vertical sulphide veins may cause hole orientations to be changed in future drill
programmes.
Sample security
The measures taken to ensure sample security.
Chain of custody is managed by Impact Minerals Ltd. Samples for Mulga Tank are stored on site
and delivered by Impact Minerals Ltd personnel to Kalgoorlie for initial sample preparation by
Genalysis who then transport the samples to Perth for assay. Whilst in storage, they are kept in a
locked yard. Tracking sheets have been set up to track the progress of batches of samples.
Audits or reviews
The results of any audits or reviews of sampling techniques and data.
At this stage of exploration a review of the sampling techniques and data by an external party is
not warranted. An internal review of the sampling techniques and data will be completed at the
end of the current programme.
SECTION 2 REPORTING OF EXPLORATION RESULTS
Criteria
Mineral tenement and land
tenure status
Exploration done by other
parties
JORC Code explanation
Commentary
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 Mulga Tank Project comprises 13 exploration licences covering 425 km2. Mulga Tank is
located wholly within Exploration Licence E39/988. Impact Minerals Ltd (IPT) has a 20% interest
in the tenement with Golden Cross Resources Limited (GCR: 80%). There is no Native Title Claim
over the licence.
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.
The tenement is in good standing with no known impediments. IPT has the right to earn 70%
ownership with $1.9M expenditure commitment before November 2017.
Acknowledgment and appraisal of exploration by other parties.
Limited bedrock-cover interface percussion drilling completed by previous explorers focused on
the southern contact of the dunite, a circular, strongly magnetic feature 3.5 km by 4 km in
diameter that is interpreted to represent a flat-lying ultramafic sill. A total of 28 RC and 4
diamond holes were completed.
Deposit type, geological setting and style of mineralisation.
Mulga Tank is interpreted as an ultramafic hosted primary magmatic nickel sulphide deposit,
similar in style to the Perseverance and Rocky’s Reward nickel mines at Leinster in Western
Australia. The Mulga Tank Dunite is also similar to the unit that hosts the Mount Keith
disseminated nickel sulphide deposit. There are two prospective units (Upper and Lower) that
host the initial sulphide intersections at a depth of 300 and 350 metres vertically (respectively).
Geology
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Criteria
Drill hole Information
Data aggregation methods
JORC Code explanation
Commentary
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.
Refer to Table 2 in body of text. Further details are not material for this early stage of exploration.
In reporting Exploration Results, weighting averaging techniques, maximum
and/or minimum grade truncations (e.g. cutting of high grades) and cut-off
grades are usually Material and should be stated.
All reported assays have been length weighted. No top outs have been applied. A nominal cutoff of 0.3% to 0.5% nickel has been applied.
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.
High grade massive sulphide intervals internal to broader zones of sulphide mineralisation are
reported as included intervals.
The assumptions used for any reporting of metal equivalent values should be
clearly stated.
No metal equivalent values are used for reporting exploration results.
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 (e.g. ‘down hole length, true width not
known’).
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 Figures in body of text.
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.
All results reported are representative
Balanced reporting
The Mulga Tank deposit is a flat lying ultramafic sill. Holes to date have been sub-vertical and
whilst this is perpendicular to stratigraphy, steeply dipping sulphide veins are at a sub-optimal
orientation to the drillhole.
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Criteria
JORC Code explanation
Other substantive exploration
data
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.
Further work
The nature and scale of planned further work (e.g. tests for lateral extensions
or depth extensions or large-scale step-out drilling).
Diagrams clearly highlighting the areas of possible extensions, including the
main geological interpretations and future drilling areas, provided this
information is not commercially sensitive
Commentary
The drill targets at Mulga Tank have been ranked on the basis of soil geochemistry and ground
EM results.
Information on structure type, dip, dip direction, alpha angle, beta angle, texture, shape,
roughness and fill material is stored in the structure table of the database.
Follow up work programmes will be subject to interpretation of assay results which is ongoing.
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