Best Gold Results to date at the Silica Hill Project
Released
Released
Announcement PDF
ASX ANNOUNCEMENT
Date: 20 July 2017
Number: 529/200717
BEST GOLD RESULTS TO DATE AT THE
SILICA HILL PROSPECT, COMMONWEALTH PROJECT NSW
14 metres at 4.5 g/t gold including 3 metres at 10.4 g/t gold
The thickest and highest grade gold intercept returned thus far at Silica Hill.
Only gold assays received. Silver assays expected in two to three weeks.
The intercept is of significantly higher grade than a nearby hole indicating the potential to
quickly increase the contained gold and silver ounces with further close-spaced drilling.
Mineralisation now also open to the north west. Drilling in progress.
First diamond drill hole to test conductor below Main Shaft intersects very encouraging
45 metre thick zone of disseminated and lesser vein-hosted copper sulphide. Conductor not
yet explained. Assays expected in two to three weeks.
The first follow up drill hole at Impact Minerals Limited’s (ASX:IPT) emerging high grade gold-silver
discovery at Silica Hill, part of the company’s 100% owned Commonwealth Project 100 km north of
Orange in New South Wales, has returned the thickest and highest grade gold intercept returned thus far
from the prospect.
Hole CMIPT56, a reverse circulation (RC) drill hole, has returned an intercept of:
14 metres at 4.5 g/t gold from 153 metres down hole including
3 metres at 10.5 g/t gold from 160 metres down hole.
The 14 metre intercept lies within a 40 metre thick intercept with greater than 0.1 g/t gold. Note that
only the assays for gold have been received for this intercept. Gold assays for the remainder of the hole
together with silver and other metals are expected within three weeks.
Impact Minerals Managing Director Dr Mike Jones said:
“This excellent intercept further demonstrates the potential for Silica Hill to deliver a signficant
discovery and we can draw three signifcant conclusions from it.
First, as we have suspected, there are likely to be zones of much higher grade gold in the system to
accompany the exceptional silver grades of up to 3,100 g/t already discovered.
Secondly, we are seeing signifcant improvements in grade with closer spaced drilling and this offers the
opportunity to rapidly increase the ounces of contained gold and silver within the area already
discovered.
Thirdly, the mineralisation is now open to the north west. These are all very encouraging
developments.”
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
Figure 1. Significant drill results at Silica Hill. The mineralisation is open in all directions.
The new intercept is interpreted to be the north west extension of, and is materially better than, the
gold-rich zone discovered by Impact in Hole 43 (Figure 1) which returned:
68 metres at 0.5 g/t gold and 43 g/t silver (1.3 g/t gold equivalent) from 99 metres;
including the upper silver-rich zone of 37 metres at 0.1 g/t gold and 71 g/t silver (2.3 ounces) and the
lower gold-rich zone of 18 m at 1.7 g/t gold and 24 g/t silver from 149 metres.
Individual results of note in Hole 43 are:
High grade silver intercepts (with gold) in the upper part of the assayed zone:
1 m at 122 g/t (4 ounces) silver and 0.2 g/t gold from 108 metres;
1 m at 146 g/t silver (5 ounces) and 0.1 g/t gold from 118 metres;
2 m at 373 g/t (12 ounces) silver and 0.2 g/t gold from 123 metres including
1 m at 525 g/t (17 ounces) silver and 0.1 g/t gold from 124 metres; and
1 m at 337 g/t (11 ounces) silver and 0.1 g/t gold and from 134 metres.
Significant gold assays in the lower part of zone:
1 m at 2.3 g/t gold and 64 g/t (2 ounces) silver from 153 metres;
and 1 m at 6.4 g/t gold and 18 g/t silver (0.5 ounces) from 155 metres.
Holes 56 and 43 are about 15 metres apart with the gold grades increasing to the north west. A further
drill hole is in progress to test the along trend extension of the mineralised zone.
Impact’s work has shown that the mineralisation at Commonwealth-Silica Hill is part of a gold-rich
VMS system (volcanogenic massive sulphide) and has strong similarities to the Eskay Creek Mine in
Canada (>4 million ounces of gold and 150 million ounces of silver – see announcement 9 May 2017).
This comparison has lead to the recognition that there is signficant potential to increase the possible
contained ounces of gold and silver within the envelop of mineralisation already discovered with closer
spaced drilling.
Conductor Below Main Shaft
Diamond drill hole CMIPT050 has been completed to test a Induced Polarisation conductivity anomaly
at depth below Main Shaft and a previous drill intercept of:
30 metres at 0.13% copper including 1 metre at 0.7% copper, 1.1% zinc, 0.4% lead,
31 g/t silver and 0.4 g/t gold (see announcement 25 May 2017).
The drill hole has intersected a 45 metre thick zone of disseminated and lesser vein hosted copper
sulphide from 269 metres depth. This is 50% thicker than the previous drill intercept and is very
encouraging. This supports Impact’s interpetation that there is increasing copper mineralisation at depth.
However, the source of the conductor has not yet been found and a down hole EM survey will be
completed to better define the source of the anomaly.
Progress of Drill Programme
The drill programme at Commonwealth has taken longer than anticipated because of technical
difficulties, in paritcular ground conditions and water loss for the diamond rig and the need for down
hole surveys every 30 metres with the RC rig. A second diamond hole from Silica Hill was abandoned
at 270 metres depth before reaching its target. The diamond rig has now moved to follow up the new
high grade gold intercepts in Hole 56. The RC rig is testing the north east extension of the
mineralisation.
About the Commonwealth Project
The Commonwealth Project forms part of Impact’s extensive 100% owned land holding of 1,000 sq km
in the Lachlan Foldbelt, home to numerous gold and copper mines including the giant Cadia deposit
near Orange (40 million ounces of gold and 12 million tonnes of copper).
At Silica Hill significant gold and silver mineralisation has been intersected in six previous drill holes
(now seven) and covers an area of 200 metres by 100 metres down to a depth of 120 metres below
surface and with an average true thickness of at least between 50 metres and 70 metres. The
mineralisation is open in all directions including up dip (Figure 1).
Four drill holes out of the six have also returned gram-times-metre intercepts of more than
100 gram.metres. These are robust and significant results for potential bulk mining and indicate the
potential to significantly increase the resources at the Commonwealth Project, which currently stand at
720,000 tonnes at 2.8 g/t gold, 48 g/t silver, 1.5% zinc and 0.6% lead (see announcement
19 February 2015).
In detail, these thick widths of mineralisation actually comprise numerous narrow veins and vein
stockworks of high grade gold and very high grade silver hosted by the Silica Hill rhyolite that contain
lower grade disseminated gold and silver.
For example, Hole CMIPT046 returned an intercept of
41 metres at 2 g/t and 176 g/t silver from 61 metres including 30 individual assays of varying widths
of between 2 g/t and 24 g/t gold and 12 individual assays with more than 500 g/t silver including
1 metre at 12.2 g/t gold and 680 g/t silver including 0.3 metres at 23 g/t gold and 1,110 g/t silver;
1 metre at 5.3 g/t gold and 924 g/t silver;
1.7 metres at 3.8 g/t gold and 1,176 g/t silver; and
0.7 metres at 1.5 g/t gold and 855 g/t silver.
(see announcements dated 5th December 2016 and 22nd February 2017).
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. The relevant announcements for this report
are listed below and also contain the relevant Table outlining the JORC requirements.
.
Silica Hill and Commonwealth continue to expand 22 February 2017.
Drilling commences at Silica Hill gold-silver discovery near Orange in NSW 5 December 2016.
Maiden High Grade Resource at Commonwealth 19 February 2015.
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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