High Grade Copper-Nickel-PGE Assays at Red Hill, Broken Hill
Released
Released
Announcement PDF
ASX ANNOUNCEMENT
Date: 17 December 2014
Number: 383/171214
HIGH GRADE COPPER-NICKEL-PGE ASSAYS
AT RED HILL PROSPECT, BROKEN HILL
Assays from the first drill hole from Impact Minerals Limited’s (ASX:IPT) maiden drill
programme at the Red Hill Prospect near Broken Hill in New South Wales have confirmed
the discovery of several near surface zones of high-grade copper and platinum group
elements (PGE) together with nickel, silver and gold within a 32 metre thick zone of
mineralisation.
The assays define three main zones of mineralisation within the broader zone (Figure 1,
Table 1):
1. 9.9 m at 1.4% copper, 0.3% nickel, 6.7 g/t Pt-Pd-Au and 19 g/t silver from 67 metres
including 4.2 m at 2.6% copper, 0.5% nickel 10.6 g/t Pt-Pd-Au from 71.6 metres.
2. 9.5 m at 1.5% copper, 0.8% nickel, 4.7 g/t Pt-Pd-Au and 14 g/t silver from 53.7 metres
including 1.9 m at 2.0% copper, 1.2% nickel, 4.7 g/t Pt-Pd-Au and 16 g/t silver from 53.7 m
and also including 5.1 m at 1.9% copper, 0.9% nickel, 6.2 g/t Pt-Pd-Au and 18 g/t silver
from 57. 3 metres.
3. 3.7 m at 0.4% copper, 0.7% nickel, 2.1 g/t Pt-Pd-Au and 3 g/t silver from 46 m.
These three zones can be combined
into one broader intercept of bulk
mineable width within hole RDH001
of:
32 metres at 1% copper,
0.5% nickel, 3.9 g/t Pt+Pd+Au and
10.6 g/t silver from 46 m down hole.
A follow up drill hole to further test
this area will commence shortly. The
mineralisation is in part coincident
with an IP anomaly that suggests
that it extends to at least 100 m
below surface.
26 Richardson Street West Perth Western Australia 6003
Tel +61 (8) 6454 6666 Facsimile +61 (8) 6454 6667
Email info@impactminerals.com.au www.impactminerals.com.au
The mineralisation comprises zones of veins and breccias which contain a mixture of nickel
and copper sulphide, oxide and carbonate minerals together with pyrite and pyrrhotite. In a
few places the veins comprise massive sulphide up to 20 cm thick and these may have been
remobilised from a larger body of massive sulphide at depth or along strike (Figure 2).
Importantly, two of the zones do not appear to have any surface expression (Figure 1).
The veins and breccias are interpreted to dip steeply to the south and occur within
metasedimentary rocks beneath a thin unit of shallow dipping ultramafic rock that forms
part of the Red Hill intrusion (Figures 2 and 3). The true width of the mineralised zones is
not yet known and further drill holes to test the up dip and down dip extent are being
planned.
Figure 2a. Nickel
and iron
sulphides.
Figure 2b. Boxwork
gossan texture
replacing massive
iron sulphide.
Figure 2c. Iron oxide
(haematite) replacing
iron sulphide and
nickel sulphide with
fresh copper sulphide
in vein at contact
between mafic unit
and metasediment.
Figure 2d. Contact
between metasedimentary
rock and 15 cm thick
chalcopyrite-chalcocite
(secondary sulphide.
Other Drill Holes
Three further drill holes (RHD002, 3 and 4) have been completed and a fifth (RHD005) is in
progress to test an EM anomaly to the immediate north west of the Red Hill intrusion
(Figure 3 and Table 2). Hole RHD002, drilled to test an IP anomaly initially modelled to be
west of RDH001, did not intersect significant mineralisation. A reinterpretation of the IP
anomaly suggests that it is related to the mineralisation in RHD001 and extends to at least
100 m below surface. At least one further hole is planned to further test this anomaly below
RHD001.
Holes RHD003 and 004 were designed to test the depth extent of the Red Hill intrusion. The
intrusion is shallower than modelled by magnetic data. No significant sulphide was
encountered but the host intrusion may contain platinum group metals and samples have
been sent for assay. In addition further mapping has shown the intrusion is likely to have
been folded and a re-assessment of the location of potential mineralised structures below
the intrusion is in progress.
Table 1. Assay results, drill intercepts and cut off grades for RHD001
Hole ID
From
RHD001
including
and
including
also
including
including
also
including
46
78
46
49.7
53.7 55.64
53.7 63.2
32
3.7
1.9
9.5
Cu
%
0.97
0.44
2.01
1.53
57.27 62.4
5.1
1.9 0.88
6.2
3.2 2.9 0.2 17.6
1
67
76.93
9.9
1.44 0.3
6.7
2.5 3.9 0.3 19.2
0.4
71.6
75.8
4.2
2.59 0.49
10.6
4.9 5.4 0.4
1
To
Interval
Ni%
0.45
0.65
1.19
0.79
PGE(+Au)
g/t
3.9
2.1
4.7
4.7
Pt
1.5
0.5
1.1
2.2
Cutoff
Cu%
2.3 0.1 10.6 0.1
1.6 0
3
0.4
3.4 0.2 15.9
1
2.4 0.1 13.6 0.4
Pd Au
Ag
0
Table 2. Drill Hole Summary
Collar ID
Prospect Drill type
Easting
Northing
Dip
Azimuth
Depth
RHD001
Red Hill
Mine
Diamond
555372
6454310
-55
10
94
Diamond
555372
6454302
-75
300
243.5
Diamond
555431
6454598
-80
225
229.9
Diamond
555517
6454391
-60
255
210.4
RHD002
RHD003
RHD004
Red Hill
Mine IP
Simons
Find
Central
IP
This is the first significant drill intercept of nickel and copper within Impact’s project area
away from the high grade drill intercept of 2 m at 6.1% nickel, 4.5% copper, 10.9 g/t platinum
and 23.6 g/t palladium in fresh sulphide discovered some years ago at the Platinum Springs
prospect some 15 km to the north east. There are many strike kilometres of the same
ultramafic host rock that contain high grade nickel-copper-PGE rock chip assays similar to
those at Platinum Springs and Red Hill that have never been drilled. These results at Red
Hill confirm Impact’s belief that there is potential for a significant discovery near Broken
Hill.
Impact recently earned a 51% in the rights to nickel-copper-PGE mineralisation in the
Broken Hill Project from Golden Cross Resources Limited (GCR) and has elected to earn an
80% interest by spending a further $200,000. This expenditure will be completed during the
current drill programme, for which Impact was recently awarded a grant of $125,000 under
the N.S.W. State Government’s Co-operative Drilling Funding Programme.
The Red Hill Prospect
The host ultramafic intrusive unit at Red Hill, which outcrops over an area of about
500 sq metres, has a nickel-rich core and copper-precious metal-rich margins (Figure 1 and
announcement dated 21 May 2014). This is a common feature in many major nickel-copperprecious metal sulphide deposits around the world.
The centre of the unit is marked by nickel-in-soil values greater than 10,000 ppb and up to
16,100 ppb nickel (MMI digest) that is 100 m wide and 300 m long. The current drill
programme has helped reaffirm this area as a priority target for drilling. Both the western
and, in particular, the eastern margins of the unit are marked by copper-in-soil results
greater than 2,500 ppb and up to 16,200 ppb copper (MMI digest) that are up to 200 m wide
and 600 m long (Figure 3). Within these margins there are a further three priority areas for
follow up work that contain greater than 20 ppb platinum+palladium+gold-in-soil results
(fire assay) covering several hundred square metres and which contain rock chip samples
with high grade nickel, copper and precious metal assays (Figure3):
1. At the Red Hill Shaft, mined to a depth of about 40 m in the early 1900’s, grab samples
from outcrops around the shaft returned up to 16 g/t platinum, 12.1 g/t palladium,
4.2% nickel, 7.7% copper, 1.3 g/t gold and 221 g/t silver. Rock chip samples from a
surface excavation about 50 m long located 100 m to the south of the shaft returned
up to 1 g/t platinum, 2.6 g/t palladium, 0.9% nickel, 0.8% copper, 1.8 g/t gold and
3.3 g/t silver.
2. At Simons Find, rock chip samples returned up to 0.7 g/t platinum, 1.7 g/t palladium,
0.4% nickel, 0.1% copper, 1.9 g/t gold and 6.6 g/t silver.
3. In the south east corner of the intrusion, grab samples from weathered rocks
associated with some surface diggings returned up to 22% copper, 0.2% nickel,
0.8 g/t gold and 91.1 g/t silver.
The soil geochemistry survey was completed by Impact at a spacing of 50 m by 50 m and
submitted for analysis by the MMI partial digest (nickel and copper) and fire assay (platinum,
palladium, gold and silver).
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.
RDH005
RDH003
RDH004
RDH001
RDH002
Figure 3. Geology of the Red Hill Prospect showing drill hole locations and soil geochemistry results
and rock chip assays.
APPENDIX 1 - SECTION 1 SAMPLING TECHNIQUES AND DATA
Criteria
JORC Code explanation
Sampling techniques
Drilling techniques
Drill sample recovery
Commentary
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.
Rock Chip Samples
Random rock samples were taken at surface which represented favourable geology and alteration to known
mineralisation in the region. Samples are variably weathered.
Soil Samples
Soil samples were taken at 50 m intervals from a hole 15-20 deep and sieved to -2mm to collect about 250 g of
material.
Diamond Drilling
Diamond drilling was used to produce drill core either with a diameter of 63.5 mm (HQ) or 47.6 mm (NQ). A
handheld XRF instrument was used to analyse the drill core at 50 cm intervals.
Include reference to measures taken to ensure sample representivity and the
appropriate calibration of any measurement tools or systems used
Rock Chip Samples
Representative rock chip samples at each sample site weigh between 0.8 and 1.2 kg. Soil samples are taken at a
consistent depth below surface and sieved.
Soil Samples and Drill Samples
Sample representivity was ensured by a combination of Company Procedures regarding quality control (QC) and
quality assurance / testing (QA).
Examples of QC include (but are not limited to), daily workplace and equipment inspections, as well as drilling
and sampling procedures.
Examples of QA include (but are not limited to) collection of “field duplicates”, the use of certified standards
and blank samples approximately every 50 samples.
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
Rock Chip and Diamond Drill Samples
Rock samples and split diamond core were sent to Intertek Adelaide where they were crushed, dried and
pulverised (total prep) to produce a 25-30 g sub-sample for analysis by four acid digest with an ICP/AES finish
for ore grade base metal samples and lead collection fire assay with AAS finish for gold and precious metals.
Weathered samples contained gossanous sulphide material. Soil samples were sent to SGS Perth for analysis by
the MMI digest.
The XRF data is qualitative only. A comparison between the XRF results and wet chemical assay data will be
completed on receipt of final results.
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 comprises NQ (47.6 mm diameter) and HQ (63.5 mm diameter) sized core. Impact diamond
core is triple tube and is oriented. Historical diamond core was not oriented.
Method of recording and assessing core and chip sample recoveries and results
assessed
Diamond core recoveries for all holes are logged and recorded. Recoveries are estimated to be approximately
>97% for the Red Hill Prospect. No significant core loss or sample recovery problems are observed in the drill
core.
Measures taken to maximise sample recovery and ensure representative nature
of the samples
Diamond core 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 driller.
Criteria
JORC Code explanation
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.
Logging
Commentary
No sample bias has been established.
Geological logging of samples followed company and industry common practice. Qualitative logging of samples
included (but not limited to); lithology, mineralogy, alteration, veining and weathering. Diamond core logging
included additional fields such as structure and geotechnical parameters.
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.
Magnetic Susceptibility measurements were taken for each 0.5 m diamond core interval.
For diamond core, information on structure type, dip, dip direction, texture, shape and fill material has been
recorded in the logs. RQD data has been recorded on selected diamond holes. Handheld XRF analysis was
completed at 50 cm intervals on diamond core.
Whether logging is qualitative or quantitative in nature. Core (or costean,
channel, etc) photography.
All logging is quantitative, based on visual field estimates. Systematic photography of the diamond core in the
wet and dry form was completed.
All diamond drill holes were logged in full.
The total length and percentage of the relevant intersections logged
Sub-sampling techniques and
sample preparation
Quality of assay data and
laboratory tests
Detailed diamond core logging, with digital capture was conducted for 100% of the core by Impact’s on-site
geologist.
If core, whether cut or sawn and whether quarter, half or all core taken.
All core samples were sampled by half core. Selected intervals of quarter core will be selected for check assays
if required.
If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled
wet or dry.
No RC drilling results are reported.
For all sample types, the nature, quality and appropriateness of the sample
preparation technique.
Company procedures were followed to ensure sub-sampling adequacy and consistency. These included (but
were not limited to) daily work place inspections of sampling equipment and practices, as well as sub-sample
duplicates (“field duplicates”).
Quality control procedures adopted for all sub-sampling stages to maximise
representivity of samples.
Laboratory QC procedures for rock sample and diamond drill core assays involve the use of internal certified
reference material as assay standards, along with blanks, duplicates and replicates.
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.
Rock and Soil Samples
Field duplicates were taken at selected sample sites.
Whether sample sizes are appropriate to the grain size of the material being
sampled.
Diamond Core Samples
Quarter core duplicate samples are taken randomly every 50 samples. Sample sizes at Red Hill are considered
adequate due to mineralisation style.
The nature, quality and appropriateness of the assaying and laboratory
procedures used and whether the technique is considered partial or total.
An industry standard fire assay technique for samples using lead collection with an Atomic Absorption
Spectrometry (AAS) finish was used for gold and aqua regia digest for base metals and silver.
Criteria
Verification of sampling and
assaying
Location of data points
Data spacing and distribution
Orientation of data in relation to
geological structure
JORC Code explanation
Commentary
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. A handheld XRF was used for
qualitative analysis only.
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.
Rock Chip Samples
For the rock chips, quality control procedures for assays were followed via internal laboratory protocols.
Accuracy and precision are within acceptable limits.
Diamond Drill Samples
Reference standards and blanks are routinely inserted into every batch of samples at a rate of 1 in every 50
samples.
The verification of significant intersections by either independent or alternative
company personnel.
The results have not been verified by independent or alternative companies. This is not required at this stage of
exploration.
The use of twinned holes.
No drilling results are reported.
Documentation of primary data, data entry procedures, data verification, data
storage (physical and electronic) protocols.
Primary assay data for rock chips has been entered into standard Excel templates for plotting in Mapinfo. All
historical drill data has been entered digitally by previous explorers and verified internally by Impact.
Discuss any adjustment to assay data.
There are no adjustments to the assay data.
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.
Sample locations and drill holes were located by hand held GPS.
Specification of the grid system used.
The grid system for Broken Hill is MGA_GDA94, Zone 54.
Quality and adequacy of topographic control.
Standard government topographic maps have been used for topographic validation.
For the diamond holes, down-hole single shot surveys were conducted by the drilling contractor. Surveys were
conducted at 15 m, 30 m and then approximately every 30 m down-hole.
Data spacing for reporting of Exploration Results.
Sample spacing for the soil survey was on a 50 m by 50 m grid.
Reconnaissance drill spacing is approximately 200 m.
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.
Estimations of grade and tonnes have not yet been made.
Whether sample compositing has been applied.
Sample compositing has not been applied.
Whether the orientation of sampling achieves unbiased sampling of possible
structures and the extent to which this is known, considering the deposit type.
Not relevant to soil and rock chip results.
The orientation of mineralisation in RHD001 yet to be determined.
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.
Not relevant to soil and rock chip results or early stage exploration drill results.
Criteria
JORC Code explanation
Commentary
Sample security
The measures taken to ensure sample security.
Chain of custody is managed by Impact Minerals Ltd. Samples for Broken Hill are delivered by Impact Minerals
Ltd by courier who transports them to the laboratory for prep and 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.
SECTION 2 REPORTING OF EXPLORATION RESULTS
Criteria
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 Broken Hill Project currently comprises 1 exploration licences covering 100 km2. The tenement is held 100%
by Golden Cross Resources Ltd. Impact Minerals Limited is earning 80% of the nickel-copper-PGE rights in the
licence from Golden Cross. No aboriginal sites or places have been declared or recorded over the licence area.
There are no national parks over the license area.
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.
Exploration done by other parties
Acknowledgment and appraisal of exploration by other parties.
There has been no significant previous work at this prospect.
Geology
Deposit type, geological setting and style of mineralisation.
Nickel-copper-PGE sulphide mineralisation associated with an ultramafic intrusion.
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.
See Table in text.
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 cuts have been applied. A cut-off of approximately
0.1% Cu, 0.4% Cu and 1.0% Cu has been applied for reporting of exploration results.
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 disseminated sulphide mineralisation are
reported as included intervals.
The assumptions used for any reporting of metal equivalent values should be
clearly stated.
No metal equivalents have been reported.
Mineral tenement and land
tenure status
Data aggregation methods
Criteria
JORC Code explanation
Commentary
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
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
The orientation of mineralisation in RHD001 is yet to be determined.
Assessment of other substantive exploration data is not yet complete however considered immaterial at this
stage.
Follow up work programmes will be subject to interpretation of results which is ongoing.
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