Priority Drill Targets for Massive Sulphide at Commonwealth
Released
Released
Announcement PDF
ASX ANNOUNCEMENT
Date: 25 May 2017
Number: 517/250517
PRIORITY DRILL TARGETS FOR MASSIVE SULPHIDES AT
MAIN SHAFT NORTH, COMMONWEALTH PROJECT, NSW
Specific drill targets have now been identified with the potential to significantly extend the high grade
gold-silver-zinc-lead-copper massive sulphide mineralisation that forms part of the Commonwealth
deposit at Impact Minerals Limited’s (ASX:IPT) 100%-owned Commonwealth Project 100km north of
Orange, New South Wales (Figure 1).
The targets occur at depth below and along trend from Main Shaft which lies at the northern end of the
Commonwealth deposit. Accordingly this new area is called the Main Shaft North Prospect (Figure 1).
Figure 1. Geology and exploration results for the Silica Hill-Commonwealth area. The
Main Shaft North Prospect lies along trend from the Commonwealth Resource.
26 Richardson Street West Perth Western Australia 6005
Tel +61 (8) 6454 6666 Facsimile +61 (8) 6454 6667
Email info@impactminerals.com.au www.impactminerals.com.au
The new targets have been generated and prioritised for drilling from a detailed interpretation of three
lines of Induced Polarisation (IP) conductivity data and from soil geochemistry data (Figures 1, 2 and
3).
IP conductivity anomalies may represent massive sulphide bodies, such as that found at Main Shaft at
the northern end of the Commonwealth deposit. Here, a relatively small massive sulphide lens about
50 metres by 50 metres by about 8 metres thick in size has an Inferred Resource of 145,000 tonnes at
4.5 g/t gold, 4.8% zinc, 1.7% lead and 0.2% copper (10 g/t gold equivalent for 47,000 gold equivalent
ounces; see announcement 19 February 2015).
Of note is that this small massive sulphide body has been clearly identified in the IP conductivity data
(Figure 2).
The massive sulphide resource is contained within the larger Commonwealth deposit which has an
Inferred Resource of 720,000 tonnes at 2.8 g/t gold, 48 g/t silver, 1.5% zinc and 0.6% lead
(4.5 g/t gold equivalent for 110,000 gold equivalent ounces; see announcement 19 February 2015).
At Main Shaft North the new targets to be drilled occur on three specific traverses along trend from
Main Shaft and within the large area of up to one square kilometre which contains numerous undrilled
IP and gold- and silver-in soil anomalies north of the small area drilled to date (Lines 10,000 mN,
10,100 mN and 10,200 mN, Figures 1, 2 and 3).
All three traverses comprise coincident good IP conductivity anomalies and coincident lead-zinccopper-in-soil anomalies.
Figure 2. IP Conductivity data along Section 10,000 mN showing the massive sulphide body at Main
Shaft and copper-rich drill hole CMIPT06.
On Line 10,000 mN the IP conductivity data has clearly identified the small massive sulphide body at
Main Shaft above the main rhyolite unit (Figure 2). A larger and stronger anomaly has been identified at
about 200 metres below surface and just below the deepest hole drilled at Main Shaft (CMIPT06, Fig 2).
This hole has returned the thickest and highest grade copper mineralisation yet discovered within the
Commonwealth deposit of:
30 metres at 0.13% copper from 209 metres, including 1 metre at 0.7% copper, 1.1% zinc,
0.4% lead, 31 g/t (one ounce) silver and 0.4 g/t gold and 1 metre at 1% copper, 2% zinc and
14 g/t silver.
This is a significant intercept and the conductor below it is an obvious target. The conductor appears to
lie below the rhyolite and it may represent a copper-rich “feeder zone” to the upper massive sulphide
deposit.
On Line 10,100 mN a significant coincident lead+zinc+copper-in-soil anomaly of about 1,000 ppm
combined, occurs over the northern extension of the rhyolite unit associated with the massive sulphide
mineralisation. There is a strong conductivity contrast below this anomaly.
On Line 10,200 mN an IP conductivity anomaly occurs at about 200 metres below surface in a similar
position along trend from that on 10,000mN. This is directly overlain by another significant
lead+zinc+copper-in-soil anomaly of up to 820 ppm combined (Figure 3).
Figure 3. IP Conductivity data along Section 10,200 mN showing coincident IP conductivity and leadzinc-copper-in-soil anomalies. The gold-in-soil anomaly is coincident with strong IP chargeability
anomalies (see announcement 9 May 2017).
The nature and location of the IP conductivity anomalies and their coincidence with strong lead-zinccopper-in-soil anomalies is very encouraging for the discovery of further high-grade massive sulphide
mineralisation.
These new targets lie up to 200 metres west of and are separate to, other recently identified drill targets
in IP chargeability data at the nearby Silica Hill Prospect where Impact has discovered high grade
gold-silver mineralisation. The chargeability anomalies may represent disseminated sulphides (Figure 1
and see announcement 9 May 2017).
TIMING OF DRILL PROGRAMME
A significant drill programme to test these new anomalies and those identified at Silica Hill and also at
Welcome Jack will commence on the completion of the Share Purchase Plan which is currently
underway.
Under the Share Purchase Plan and related Shortfall Offer, existing Shareholders on the Company’s
register of Shareholders as of Wednesday, 10 May 2017 can subscribe for new fully paid ordinary
shares in the Company at an issue price of $0.018 each, with three free attaching options exercisable at
$0.04 each, on or before 15 June 2020 (Free Attaching Options) for every two New Shares issued.
Further details are in the announcement dated 11 May 2017 and all shareholders are encouraged to
participate.
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). Dr 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.
Impact Minerals confirms that it is not aware of any new information or data that materially affects the information included in the
previous market announcements referred to and in the case of mineral resource estimates, that all material assumptions and technical
parameters underpinning the estimates continue to apply and have not materially changed.
APPENDIX 1 - SECTION 1 SAMPLING TECHNIQUES AND DATA
Criteria
JORC Code explanation
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 grab samples were taken at surface which represented favourable geology and alteration to known mineralisation in the
region. Samples are variably weathered.
Soil Samples
About 250g of soil was taken from 15-20cm below surface and sieved to - 2mm size. Samples put in plastic snap seal bags.
Samples were subsequently sieved to -250 micron at SGS Laboratories for assay by aqua regia digest.
RC Drilling
Reverse Circulation (RC) percussion drilling was used to produce a 1m bulk sample (~25kg) which was collected in plastic bags and
representative 1m split samples (12.5%, or nominally 3kg) were collected using a riffle splitter and placed in a calico bag. The
cyclone was cleaned out with compressed air at the end of each hole and periodically during the drilling. Holes were drilled to
optimally intercept interpreted mineralised zones.
Diamond Drilling
Diamond drilling was used to produce drill core either with a diameter of 63.5 mm (HQ) or 47.6 mm (NQ).
Include reference to measures taken to ensure sample
representivity and the appropriate calibration of any
measurement tools or systems used
Rock chip samples
Representative samples at each sample site weigh between 0.8 and 1.2 kg. Sample sites were chosen due to historic rock and soil
assay results and the geophysical surveys conducted on the Commonwealth Project. Historic rock sample methods are unknown
but are considered immaterial.
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
Sampling techniques
Criteria
Drilling techniques
Drill sample recovery
JORC Code explanation
Commentary
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 samples
Rock samples were sent to SGS Perth where they were crushed, dried and pulverised (total prep) to produce a 25-30 g subsamples for analysis initially by Aqua Regia digest with ICP-MS finish for base metals then 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.
Soil Samples
Soil samples were sent to ACME Laboratories in Vancouver for analysis by aqua regia digest or to SGS Laboratories in Perth for
analysis by the MMI digest.
RC and diamond drill samples
RC samples and cut samples of core were submitted to ALS in Orange, NSW. Laboratory sample preparation involved: sample
crushed to 70% less than 2mm, riffle/rotary split off 1 kg, pulverise split to >85% passing 75 microns.
RC samples analysed by MEICP41 or MEOG46 for ore grade samples, aqua region digest with ICP OES analysis and AA24 fire assay
with AAS finish.
Historical diamond and RC samples were sent to Fox Anamet, Brookvale NSW where gold was determined by fire assay, base
metals by DCP and AAS methods.
Weathered samples contained gossanous sulphide material and fresh samples containing visible pyrite, galena, sphalerite and
chalcopyrite.
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, facesampling bit or other type, whether core is oriented and if so, by
what method, etc).
Diamond drilling accounts for about 50 % of the drilling and 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.
RC drilling accounts for about 50% of the drilling and comprises 4 inch hammer.
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
Commonwealth Project. No significant core loss or sample recovery problems are observed in the drill core or historic reports. RC
samples were visually checked for recovery, moisture and contamination.
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.
The RC samples are collected by plastic bag directly from the rig-mounted cyclone and laid directly on the ground in rows of 10.
The drill cyclone and sample buckets are cleaned between rod-changes and after each hole to minimise down-hole and/or cross
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.
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.
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.
Magnetic Susceptibility measurements were taken for each 1m RC sample and each 1m 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 and 1 m intervals on
diamond core and for every metre for RC samples.
Logging
Criteria
Sub-sampling
techniques and
sample preparation
Quality of assay data
and laboratory tests
Verification of
sampling and assaying
JORC Code explanation
Commentary
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.
Chip trays with representative 1m RC samples were collected and photographed then stored for future reference.
The total length and percentage of the relevant intersections
logged
All diamond drill holes were logged in full.
All RC chips samples were geologically logged by Impact’s on-site geologist on a 1m basis, with digital capture in the field.
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.
RC samples were split using a riffle splitter.
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 assays involve the use of internal certified reference material as assay standards, along
with blanks, duplicates and replicates.
The QC procedure for historical diamond and RC samples is unknown but considered immaterial.
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.
Sample duplicates from the historical drilling were taken from selected intervals and compared to the original assay. Quarter core
was taken for diamond samples and riffle resplits for RC samples.
Whether sample sizes are appropriate to the grain size of the
material being sampled.
The samples sizes at Commonwealth are considered appropriate since gold has been identified as predominantly fine-grained by
thin section analysis which would indicate the nugget effect is minimal.
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.
The quality of historical drill sample assays is unknown, however this is considered immaterial at this stage of exploration.
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.
For the rock chips, quality control procedures for assays were followed via internal laboratory protocols. Accuracy and precision
are within acceptable limits.
The quality control of historical drill sample assays is unknown, however this is considered immaterial at this stage of exploration.
The verification of significant intersections by either independent
or alternative company personnel.
Significant intersections from drilling have not been verified by independent or alternative companies. This is not required at this
stage of exploration.
Criteria
Location of data
points
JORC Code explanation
Commentary
The use of twinned holes.
Two twin diamond holes versus historic RC holes have been drilled at Commonwealth South and Main Shaft.
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 and Target. All historical
drill data has been entered digitally by previous explorers and verified internally by Impact.
Discuss any adjustment to assay data.
No significant adjustments have been required.
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.
Recent drill holes have been located by DGPS. Historical drill holes and mine shafts have been verified by DGPS.
Specification of the grid system used.
The grid system for Commonwealth is MGA_GDA94, Zone 55.
Quality and adequacy of topographic control.
Standard government topographic maps have been used for topographic validation. The DGPS is considered sufficiently accurate
for elevation data.
For the diamond holes, down-hole single shot surveys were conducted by the drilling contractor. Surveys were conducted at 6m,
18, 30m and then approximately every 30m down-hole.
For the RC drill holes, downhole dip surveys were taken at approximately 30m intervals and at the bottom of the hole.
Data spacing for reporting of Exploration Results.
Drill spacing of drill holes ranges between 10 and 30 m which is considered adequate for 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.
Drill spacing of drill holes ranges between 10 and 50 m and may be considered adequate for Mineral Resource and Ore reserve
estimation procedures. However estimations of grade and tonnes have not yet been made.
Whether sample compositing has been applied.
Sample compositing has been applied for quoting drill composite results only.
Whether the orientation of sampling achieves unbiased sampling
of possible structures and the extent to which this is known,
considering the deposit type.
Drilling is oriented sub-perpendicular to the mineralised trend and stratigraphic contacts as determined by field data and cross
section interpretation.
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 significant sample bias has been identified from drilling due to the optimum drill orientation described above. Where present,
sample bias will be reported.
Sample security
The measures taken to ensure sample security.
For rock samples, chain of custody is managed by Impact Minerals Ltd. Samples for Commonwealth are delivered by Impact
Minerals Ltd personnel to ALS in Orange, NSW or to SGS Perth 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.
Security of historic drill samples is unknown however is considered immaterial.
Audits or reviews
The results of any audits or reviews of sampling techniques and
data.
A review of the sampling techniques and data both of historic drill holes and of Impact’s procedures has been completed by
Optiro Consultants of Perth, WA.
Data spacing and
distribution
Orientation of data in
relation to geological
structure
SECTION 2 REPORTING OF EXPLORATION RESULTS
Criteria
Mineral tenement and land
tenure status
Exploration done by other
parties
JORC Code explanation
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 Commonwealth Project currently comprises 3 exploration licences covering 315 km2. The tenements
are held 100% by Endeavour Minerals Pty Ltd, a subsidiary company of Impact Minerals Limited. No
aboriginal sites or places have been declared or recorded in areas where Impact is currently exploring.
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 tenements are in good standing with no known impediments.
Acknowledgment and appraisal of exploration by other parties.
A total of 66 drillholes have been completed over 300 m strike between the Commonwealth main shaft
and Commonwealth South by previous explorers to an average depth of 53 m.
Deposit type, geological setting and style of mineralisation.
The Commonwealth and Commonwealth South deposits are considered gold-rich volcanic hosted massive
sulphide (VMS) deposits that occur at and below the contact with a porphyrictic rhyolite and overlying
volcanic sedimentary rocks. The mineralisation may have been overprinted by epithermal mineralisation.
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 nominal cut-off of
approximately 0.5 g/t Au 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 disseminated sulphide mineralisation
are reported as included intervals.
The assumptions used for any reporting of metal equivalent values should
be clearly stated.
Gold equivalent values have been used in the long section. Metal prices used for the gold equivalent
were $1,650 for gold and $30 for silver. Given the high grade results, it is assumed that very high
recoveries will be achieved. However no metallurgical studies have been completed to verify this. Such
studies will be done as and when appropriate.
Geology
Drill hole Information
Data aggregation methods
Commentary
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
Historical drill holes to date have been sub-perpendicular to the mineralised trend and stratigraphy so
intervals are close to true width or otherwise stated.
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 recent and historic results which is
ongoing.
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