REG - Castillo Copper Ltd - Results deliver upgrades at Broken Hill
02/08/2022 07:00
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RNS Number : 5335U Castillo Copper Limited 02 August 2022
2 August 2022
CASTILLO COPPER LIMITED
("Castillo" or the "Company")
Metallurgical results deliver solid upgrades at Broken Hill with resource
drilling planned
Castillo Copper Limited (LSE and ASX: CCZ), a base metal explorer primarily
focused on copper across Australia and Zambia, is pleased to announce that
several rounds of preliminary metallurgical test-work on BH1 drill-core (The
Sisters Prospect; East Zone) produced excellent beneficiation results for
cobalt-copper-gold.
HIGHLIGHTS
· Metallurgical test-work on BH1 drill-core extracted from The Sisters
Prospect(1) - BHA Project's East Zone (Appendix A) - delivered excellent
beneficiation results for cobalt and, surprisingly, copper-gold (Appendix B) -
with the best outcomes:
o Cobalt: 200ppm head-grade up to 2,500ppm post-test-work; 12x upgrade
o Copper: 520ppm head-grade up to 16,000ppm (1.6%) post-test-work; 30x upgrade
o Gold: 0.02g/t Au head-grade up to 3.87g/t Au post-test-work; >190x
upgrade
· The original BH1 drill-core the samples were extracted from
comprised:
o 24m @ 424ppm Co from 103m including 2m @ 1,120ppm Co from 107m; 1m @ 873ppm
Co from 120m; and 2m @ 486ppm Co from 125m (BH1)1
· The metallurgical test-work showed that cobalt-copper-gold liberated
easily from BH1 drill-core samples to produce a potentially viable concentrate
(Figure 1)
· Moving forward, the Board's primary focus for the East Zone is to
increase the confidence in the current inferred Mineral Resource Estimate
(MRE) which stands at 21,556t cobalt (64Mt @ 318 ppm Co) and 44,260t copper
(63Mt @ 0.07% Cu)(2)
· As such, the geology team are close to finalising optimal cobalt
targets across several prospects for the inaugural drilling campaign, which
will be implemented once regulatory approvals are secured:
o To date, land-holder approval has been secured and access routes mapped out
Dr Dennis Jensen, Managing Director of Castillo Copper, commented: "The Board
was pleasantly surprised upon learning of the exceptional metallurgical
results, especially nearly 4 g/t gold and 1.6% copper which provide new
dynamics to follow up. However, the Board's current prime focus is to increase
the confidence in the inferred cobalt resource with a highly targeted drilling
campaign across several prospects, with planning to be finalised shortly."
FIGURE 1: METALLURGICAL TESTING - CONCENTRATE EXAMPLE
Source: ALS Metallurgy, Perth, Western Australia
Drilling campaign to increase MRE confidence
To improve confidence in the current global MRE - 21,556t cobalt (64Mt @ 318
ppm Co) and 44,260t copper (63Mt @ 0.07% Cu)(2) - and potentially extend known
mineralisation, Castillo will soon undertake an inaugural drilling campaign
across several prospects within the BHA Project's East Zone.
The geology team are close to finalising optimal cobalt targets and subject to
Board approval, will then file an application with the NSW Resources Regulator
to implement the drilling campaign.
Previous field trips and land-holder meetings have already formalised
approvals and enabled access routes to be mapped out.
For further information, please contact:
Castillo Copper Limited +61 8 6558 0886
Dr Dennis Jensen (Australia), Managing Director
Gerrard Hall (UK), Chairman
SI Capital Limited (Financial Adviser and Corporate Broker) +44 (0)1483 413500
Nick Emerson
Luther Pendragon (Financial PR) +44 (0)20 7618 9100
Harry Chathli, Alexis Gore
About Castillo Copper
Castillo Copper Limited is an Australian-based explorer primarily focused on
copper across Australia and Zambia. The group is embarking on a strategic
transformation to morph into a mid-tier copper group underpinned by its core
projects:
· A large footprint in the Mt Isa copper-belt district, north-west
Queensland, which delivers significant exploration upside through having
several high-grade targets and a sizeable untested anomaly within its
boundaries in a copper-rich region.
· Four high-quality prospective assets across Zambia's copper-belt
which is the second largest copper producer in Africa.
· A large tenure footprint proximal to Broken Hill's world-class
deposit that is prospective for zinc-silver-lead-copper-gold and platinoids.
· Cangai Copper Mine in northern New South Wales, which is one of
Australia's highest grading historic copper mines.
The group is listed on the LSE and ASX under the ticker "CCZ."
Competent Person's Statement
The information in this report that relates to Exploration Results and Mineral
Resource Estimates for "BHA Project, East Zone" is based on information
compiled or reviewed by Mr Mark Biggs. Mr Biggs is a director of ROM
Resources, a company which is a shareholder of Castillo Copper Limited. ROM
Resources provides ad hoc geological consultancy services to Castillo Copper
Limited. Mr Biggs is a member of the Australian Institute of Mining and
Metallurgy (member #107188) and has sufficient experience of relevance to the
styles of mineralisation and types of deposits under consideration, and to the
activities undertaken, to qualify as a Competent Person as defined in the 2012
Edition of the Joint Ore Reserves Committee (JORC) Australasian Code for
Reporting of Exploration Results, and Mineral Resources. Mr Biggs holds an
AusIMM Online Course Certificate in 2012 JORC Code Reporting. Mr Biggs also
consents to the inclusion in this report of the matters based on information
in the form and context in which it appears.
References
1) CCZ ASX Release - 5 May 2022
2) CCZ ASX Release - 1 June 2022
APPENDIX A: PROSPECT'S IN BHA PROJECT'S EAST ZONE
Source: CCZ geology team
APPENDIX B: METHODOLOGY AND TEST-WORK
Castillo contracted ALS Metallurgy, Perth, Western Australia to undertake the
preliminary rougher test-work on the BH1 drill-core sample.
The core for metallurgical testing is from EL8435 in NSW, near Broken Hill,
from a historic mine called "The Sisters" and from a NQ diamond core hole BH1,
drilled by Falconbridge in 1970. The cored hole comes courtesy of the GSNSW
E.C. Andrews core library in Broken Hill.
This composite of about 14m goes around 494ppm cobalt (inc. a 1m sample as
high as 1,120ppm), with some copper (0.1%) and a little bit of silver and
maybe some TREO present. The main target is cobalt which is probably
interspersed and locked within pyrite.
As part of this strategy and to further test the economic potential of BHA
Project's East Zone, cobalt preliminary rougher testing was recently completed
by ALS Metallurgy's laboratory using an approximately 16kg composite derived
from drill-hole (BH1) as shown in Figure B1 below:
FIGURE B1: THE SISTERS SAMPLE FOR METALLURGICAL TESTING
Drillhole XRF Samp SampleID From To Length (m) Weight (kg) Ag_ppm Co_ppm Cu_ppm Ag Mass Co Mass Cu Mass
BH1 BH1.18 CCZ03785 103.07 104.73 1.66 0.65 0.32 712 483 0.01 28.44 19.30
BH1 BH1.19 CCZ03786 104.73 106.62 1.89 0.84 0.2 450 773 0.01 23.23 39.91
BH1 BH1.20 CCZ03787 106.62 108.51 1.89 0.94 0.29 1120 1260 0.02 64.71 72.80
BH1 BH1.21 CCZ03788 108.51 110.46 1.95 1.54 0.04 93.5 90.1 0.00 8.85 8.53
BH1 BH1.22 CCZ03789 110.46 112.41 1.95 1.75 0.05 23.3 167 0.01 2.51 17.96
BH1 BH1.23 CCZ03790 112.41 114.36 1.95 2.08 0.04 112.5 23.9 0.01 14.38 3.06
BH1 BH1.24 CCZ03791 114.36 116.31 1.95 1.66 0.15 62.6 33.5 0.02 6.39 3.42
BH1 BH1.25 CCZ03792 116.31 118.26 1.95 0.81 0.15 409 235.0 0.01 20.36 11.70
BH1 BH1.26 CCZ03793 118.26 119.29 1.03 0.71 0.13 419 233.0 0.01 18.28 10.17
BH1 BH1.27 CCZ03794 119.29 120.32 1.03 0.72 0.08 759 56.8 0.00 33.59 2.51
BH1 BH1.28 CCZ03795 120.32 121.35 1.03 0.7 0.33 873 196.5 0.01 37.56 8.45
BH1 BH1.29 CCZ03796 121.35 122.38 1.03 0.84 0.04 111 72.7 0.00 5.73 3.75
BH1 BH1.30 CCZ03797 122.38 123.44 1.06 0.72 0.77 193 73.6 0.03 8.54 3.26
BH1 BH1.31 CCZ03798 123.44 124.66 1.22 0.69 0.46 477 385 0.02 20.23 16.33
BH1 BH1.32 CCZ03799 124.66 125.88 1.22 0.7 1.18 727 10650 0.05 31.28 458.21
BH1 BH1.33 CCZ03800 125.88 127.10 1.22 0.92 0.49 245 4280 0.03 13.85 242.02
24.03 16.27 0.23 338 921
Source: ALS Metallurgy, Perth, Western Australia
Once at ALS Metallurgy's Perth laboratory, the head grade of the composite
sample was determined to be variable compared to the calculated arithmetic
average above, as shown in Figure B2 below.
FIGURE B2: THE SISTERS - TESTING HEAD GRADE
Analyte BH1 Composite Analyte BH1 Composite
Ag (ppm) <2 Mg (ppm) 6400
Al (%) 1.68 Mn (ppm) 100
Au (g/t) 0.02 / <0.02 Mo (ppm) <5
Ba (ppm) 60 Na (ppm) 1860
Be (ppm) <5 Ni (ppm) 45
Bi (ppm) <10 P (ppm) 9000
Ca (%) 1.70 Pb (ppm) 110
Cd (ppm) <5 SiO2 (%) 46.6
Co (ppm) 200 Sr (ppm) 160
Cr (ppm) 150 Ti (ppm) 800
Cu (ppm) 520 V (ppm) 258
Fe (%) 28.0 Y (ppm) <100
K (ppm) 1800 Zn (ppm) 230
Li (ppm) <5
Source: ALS Metallurgy, Perth, Western Australia
The laboratory considered several rougher options for targeting a bulk
concentrate (Cu/Co), with future programs looking to refine this and separate
more target material.
However, with a bulk concentrate methodology the focus, recovery takes
priority over grade at this stage. Initially, two different reagent schemes
for the bulk concentrate generation:
· Natural pH, PAX, Danafloat 245; (PAX may cause high iron collection)
· Cytec aero float, Aero 3894 with an Aero 208 promoter
The final recommendation was to try initially 10g/t of the Danafloat / Aero
208, with 5g/t of the PAX or Aero 3894. Further, consideration was given to
add additional dosage at the end of the first three concentrates (assumed
2-minute Ro concentrate), and then see if more product reports into Ro Con
4. Eventually, a series of rougher tests were carried out based on the
following methodology:
A) Sample preparation and screening analysis
· Receive samples and inventory
· Control crush P100 3.35mm (assumed no compositing)
· Rotary blending & splitting 1kg charges (12 x 1kg)
· PPS - Head assay submission
· Assay - Head sample (Au, Co, Cu, S and SiO(2), ICP Scan)
B) Flotation and gravity testing
· 1 kg grind establishment single grind target
· Rougher flotation (4 con 1 tail) (5 test allowance)
· PPS - Flotation product assay submission
· Assay - Flotation products (Au, Co, Cu, Zn, S, and SiO2)
· Gravity separation - Wilfley table - Batch test
· PPS - Table product assay submission
· Assay - Table products (Au, Co, Cu, Zn, S, and SiO(2))
Four runs were established comparing two common froth reagents (Aerofloat and
Danafloat; Figure B3) below.
New instructions for the float were based on the Danafloat reagent trialled
previously. The new float targeted an elevated pH (11) to depress the S to
give an indication if the Co / Cu are encapsulated in this material or not,
based on recovery changes.
FIGURE B3: The Sisters Metallurgical Testing Parameters
COMPOSITE The Sisters BH1 The Sisters BH1 The Sisters BH1 The Sisters BH1
TEST # BF2270 BF2271 BF2291 BF2293
WATER TYPE Perth Tap Water Perth Tap Water Perth Tap Water Perth Tap Water
REAGENT Danafloat AeroFloat Danafloat Danafloat
GRIND SIZE P80 75µm P80 75µm P80 75µm P80 25µm
PULP DENSITY 35% 35% 35% 35%
pH 5.9 5.7 11.0 11.0
Source: ALS Metallurgy, Perth, Western Australia
Figures B4 and B5 show the frother product comparison between Aerofloat and
Danfloat concentrates for Co, S, Au, and Cu; the latter at 25µm. Danafloat
products showed the best concentration of cobalt, with Ro Con 1 giving 12
times increase from a starting point of 200ppm to 2,500ppm.
FIGURE B4: METALLURGICAL TESTING - ROUGHER FROTHER PRODUCT EXAMPLE CO, S
Source: ALS Metallurgy, Perth, Western Australia
FIGURE B5: METALLURGICAL TESTING - ROUGHER FROTHER PRODUCT EXAMPLE AU, CU
Source: ALS Metallurgy, Perth, Western Australia
It should be noted the preliminary rougher testing was biased toward
establishing a viable process configuration and recovery rather than grade.
Figure B64 provides a range of improvements in grade for Au, Co, Cu and S
using the Danafloat for various concentrate runs. Note, cumulative copper
for Ro Con 1-3 gives 1.2% Cu at 72.1% recovery. Further, the high S grade of
46.9% at 92% recovery is of note.
FIGURE B6: Metallurgical Testing Danafloat Head Grade Improvement for several
elements
(a) Original Crush at 75µm
PRODUCT WEIGHT Au Co Cu SiO2 S Zn
Gram % % %dist % %dist % %dist % %dist % %dist % %dist
Ro Con 1 38.37 3.85 0.32 6.56 0.25 44.46 0.58 38.16 3.25 0.27 49.30 53.82 0.01 0.96
Ro Con 2 24.20 2.43 0.24 3.10 0.22 24.68 0.55 22.82 5.30 0.28 47.20 32.50 0.02 2.43
Ro Con 3 6.41 0.64 0.30 1.03 0.14 4.16 0.50 5.50 23.10 0.32 30.90 5.64 0.06 1.93
Ro Con 4 4.67 0.47 0.17 0.42 0.05 1.02 0.23 1.84 46.40 0.47 9.08 1.21 0.08 1.88
Ro Tail 923.70 92.62 0.18 88.88 0.01 25.69 0.02 31.68 49.60 98.67 0.26 6.83 0.02 92.80
Calc'd Head 997.35 100.00 0.19 100.00 0.02 100.00 0.06 100.00 46.56 100.00 3.52 100.00 0.02 100.00
Assay Head 0.02 0.02 0.05 46.60 0.02
Ro Con 1 3.85 0.32 6.56 0.25 44.46 0.58 38.16 3.25 0.27 49.30 53.82 0.01 0.96
Ro Con 1-2 6.27 0.29 9.67 0.24 69.14 0.57 60.98 4.04 0.54 48.49 86.32 0.01 3.39
Ro Con 1-3 6.92 0.29 10.70 0.23 73.30 0.56 66.48 5.81 0.86 46.85 91.96 0.02 5.33
Ro Con 1-4 7.38 0.28 11.12 0.22 74.31 0.54 68.32 8.39 1.33 44.46 93.17 0.02 7.20
Source: ALS Metallurgy, Perth, Western Australia
(b) Regrind at 25µm
Au Co Cu
g/t %dist % %dist % %dist
Clnr Con 1 4.84 21.13 0.17 5.61 1.60 22.53
Clnr Con 2 3.80 38.37 0.18 13.74 1.14 37.10
Clnr Con 3 2.98 12.23 0.17 5.28 1.02 13.51
Clnr Con 4 0.01 0.01 0.18 1.77 1.07 4.48
Clnr Tail 0.635 25.34 0.17 51.32 0.10 12.87
Ro Tail 0.005 2.95 0.005 22.29 0.005 9.50
Source: ALS Metallurgy, Perth, Western Australia
Results undertaken on drill-hole BH1 from The Sisters Prospect summarised
below:
Source: ALS Metallurgy, Perth, Western Australia
Source: ALS Metallurgy, Perth, Western Australia
Source: ALS Metallurgy, Perth, Western Australia
Source: ALS Metallurgy, Perth, Western Australia
APPENDIX C: JORC CODE, 2012 EDITION - TABLE 1
Section 1 Sampling Techniques and Data
(Criteria in this section apply to all succeeding sections.)
Criteria JORC Code explanation Commentary
Sampling techniques · Nature and quality of sampling (e.g., cut channels, random chips, · Regarding historical cores from holes held by the NSW Geological
or specific specialised industry standard measurement tools appropriate to the Survey across EL 8434 and 8435, selected sections that were reanalyzed using
minerals under investigation, such as down hole gamma sondes, or handheld XRF pXRF have been cut by diamond saw for laboratory analysis. This work recovered
instruments, etc.). These examples should not be taken as limiting the broad one hundred and eighty-four (184) samples, each about 1m in length (of HQ, BQ,
meaning of sampling. and NQ drill core) which were retested by ALS Brisbane, using ME-MS61R and
PGM-ICP27 methods.
· Include reference to measures taken to ensure sample
representivity and the appropriate calibration of any measurement tools or · Quarter core was submitted to ALS for chemical analysis using
systems used. industry standard sample preparation and analytical techniques.
· Aspects of the determination of mineralisation that are Material · Coarse rejects of the half core were also collected for
to the Public Report. metallurgical testwork from BH1.
· In cases where 'industry standard' work has been done this would · The location and sample interval details and grades quoted for
be relatively simple (e.g., 'reverse circulation drilling was used to obtain 1 cored intervals described in Figure 1 in the main section are given in Table
m samples from which 3 kg was pulverised to produce a 30g charge for fire AC1-1 and Figure AC1-1 at the end of this section.
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 (eg submarine nodules) may warrant disclosure of detailed
information.
Drilling techniques · Drill type (e.g. core, reverse circulation, open-hole hammer, · In and around The Sisters model area are twelve (12) drillholes,
rotary air blast, auger, Bangka, sonic, etc.) and details (e.g. core diameter, however it should be noted that the majority of these are <50m in depth,
triple or standard tube, depth of diamond tails, face-sampling bit or other but only four (4) holes >100m. Two of these are in the core library as
type, whether core is oriented and if so, by what method, etc.). shown below:
HOLE_NAME E_GDA94 N_GDA94 END_DEPTH AZIMUTH DIP DRILL TYPE
BH1 566841.77 6480228.70 152.4 263.5 -45 BQ
BH2 566721.77 6480418.70 198.8 278.5 -50 BQ
DD80RW4 559571.82 6459448.72 198.0 118.5 -60 NQ
DD80RW4_1 559571.82 6459448.72 385.0 118.5 -60 NQ
DD90_IB3 560223.79 6473890.70 383.0 90 -63 NQ
RH3 562961.79 6474868.70 52.3 294 -55 NQ
Drill sample recovery · Method of recording and assessing core and chip sample recoveries · Not applicable in this study, no new holes completed.
and results assessed. Historical drillholes, including BH1 used for this study were documented to
have >90% core recovery.
· Measures taken to maximise sample recovery and ensure
representative nature of the samples.
· 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 · Whether core and chip samples have been geologically and · The drilling that did occur was generally completed to modern-day
geotechnically logged to a level of detail to support appropriate Mineral standards. The preferred exploration strategy in the eighties and early
Resource estimation, mining studies and metallurgical studies. nineties was to drill shallow auger holes to negate the influence of any
Quaternary and Tertiary thin cover.
· Whether logging is qualitative or quantitative in nature. Core
(or costean, channel, etc) photography. · No downhole geophysical logging took place; however, measurements
of magnetic susceptibility were taken on the six-library core relogged over
· The total length and percentage of the relevant intersections the same intervals as the PXRF readings were taken.
logged.
Sub-sampling techniques and sample preparation · If core, whether cut or sawn and whether quarter, half or all · The preliminary rougher testwork methodology employed is listed
core taken. as follows:
· If non-core, whether riffled, tube sampled, rotary split, etc and Given the bulk concentrate methodology requested, recovery would take priority
whether sampled wet or dry. over the grade at this stage. Initially, two different reagent schemes for the
bulk con generation:
• Natural pH, PAX, Danafloat 245; (PAX may cause high iron
collection)
· For all sample types, the nature, quality, and appropriateness of • Cytec aero float, Aero 3894 with an Aero 208 promoter
the sample preparation technique.
The final recommendation was to try initially 10g/t of the danafloat / aero
208, with 5g/t of the PAX or Aero 3894. Consideration was also given to add
additional dosage at the end of the first 3 concentrates (assumed 2-minute Ro
concentrate), and then see if more product reports into Ro Con 4.
Eventually, a series of rougher tests (refer to Table AC1-1) were carried out
· Quality control procedures adopted for all sub-sampling stages to based on the following methodology:
maximise representivity of samples.
Sample Preparation and Screening Analysis
• Receive Samples and Inventory
· Measures taken to ensure that the sampling is representative of
the in-situ material collected, including for instance results for field • Control Crush P100 3.35mm (assumed no compositing)
duplicate/second-half sampling.
• Rotary Blending & Splitting 1kg charges (12 x 1kg)
• PPS - Head Assay Submission
• Assay - Head Sample (Ag, Au, Co, Cu, SiO2, S, ICP Scan)
· Whether sample sizes are appropriate to the grain size of the
material being sampled. Flotation and Gravity Testing
• 1 kg Grind Establishment Single grind target
• Rougher Flotation (4 con 1 tail) (5 test allowance)
• PPS - Flotation Product Assay Submission
• Assay - Flotation Products (Ag, Au, Co, Cu, Zn, SiO2)
• Gravity Separation - Wilfley Table - Batch Test
• PPS - Table Product Assay Submission
• Assay - Table Products (Ag, Au, Co, Cu, Zn, SiO2, S)
Quality of assay data and laboratory tests · The nature, quality and appropriateness of the assaying and · The samples in the composite were originally analysed at the ALS
laboratory procedures used and whether the technique is considered partial or Brisbane Laboratory using the ME-MS61R technique, as summarised below:
total.
Inductively Coupled Plasma - Atomic Emission Spectroscopy (ICP - AES)
Inductively Coupled Plasma - Mass Spectrometry (ICP-MS)
· For geophysical tools, spectrometers, handheld XRF instruments, Sample Decomposition is by HF-HNO(3)-HClO(4) acid digestion, HCl leach
etc, the parameters used in determining the analysis including instrument make (GEO-4A01).
and model, reading times, calibrations factors applied and their derivation,
etc. A prepared sample (0.25 g) is digested with perchloric, nitric, hydrofluoric,
and hydrochloric acids. The residue is topped up with dilute hydrochloric acid
and analyzed by inductively coupled plasma atomic emission spectrometry.
Following this analysis, the results are reviewed for high concentrations of
bismuth, mercury, molybdenum, silver, and tungsten and diluted accordingly.
· Nature of quality control procedures adopted (eg standards, Samples meeting this criterion are then analyzed by inductively coupled
blanks, duplicates, external laboratory checks) and whether acceptable levels plasma-mass spectrometry. Results are corrected for spectral interelement
of accuracy (i.e. lack of bias) and precision have been established. interferences.
NOTE: Four acid digestions can dissolve most minerals; however, although the
term "near total" is used, depending on the sample matrix, not all elements
are quantitatively extracted.
Results for the additional rare earth elements will represent the acid
leachable portion of the rare earth elements and as such, cannot be used, for
instance to do a chondrite plot.
· Laboratory inserted standards, blanks and duplicates were
analysed per industry standard practice. There was no evidence of bias from
these results.
Verification of sampling and assaying · The verification of significant intersections by either · None of the library drillholes (including BH1) have been twinned,
independent or alternative company personnel. as they are historical holes
.
· The use of twinned holes. · The four preliminary rougher tests results have been reproduced
in full in Appendix 1 of this ASX release.
· Documentation of primary data, data entry procedures, data
verification, data storage (physical and electronic) protocols.
· Discuss any adjustment to assay data.
Location of data points · Accuracy and quality of surveys used to locate drill holes · In general, locational accuracy does vary, depending upon whether
(collar and down-hole surveys), trenches, mine workings and other locations the samples were digitised off plans or had their coordinated tabulated.
used in Mineral Resource estimation. Many samples were reported to AGD66 or AMG84 and have been converted to
MGA94.Zone 54
· Specification of the grid system used.
· It is estimated that locational accuracy of BH1 therefore varies
between 2-50m
· Quality and adequacy of topographic control.
Data spacing and distribution · Data spacing for reporting of Exploration Results. · The average sample spacing across the tenure varies per prospect,
and sample type, as listed in Table AB1-2, below:
Table AB-2: EL 8434 and EL 8435 Drillhole Spacing
· Whether the data spacing and distribution is sufficient to
Prospect Drillholes in Model RMS Drillhole Spacing (m)
establish the degree of geological and grade continuity appropriate for the The Sisters 12 242
Mineral Resource and Ore Reserve estimation procedure(s) and classifications Rothwell 1 N/A
applied. Round Hill 1 N/A
Iron Blow 8 315
Avondale East 24 134.2
Tors Tank 342 27.4
Fence Gossan 549 25.5
Ziggy's Hill 245 37.0
· Whether sample compositing has been applied. Reefs Tank 1,375 22.1
· No sample compositing has been applied to any results in this
release..
Orientation of data in relation to geological structure · Whether the orientation of sampling achieves unbiased sampling of · The current database does not contain any sub-surface geological
possible structures and the extent to which this is known, considering the logging for Avondale East , which is being compiled (75% complete)
deposit type.
· Geological mapping by various companies has reinforced that the
· If the relationship between the drilling orientation and the strata is tightly folded, dips variously between 45 and 80 degrees, and dips
orientation of key mineralised structures is considered to have introduced a mostly to the north and northwest.
sampling bias, this should be assessed and reported if material.
Sample security · The measures taken to ensure sample security. · The sample security measures, except for the Squadron Resources
work programs is not known. Squadron took samples to their Broken Hill
office and transported samples for analysis to ALS Broken Hill. Castillo
Copper contractors relogged BH1 and used a diamond saw to sample and bag
prospective intervals within the hole including that interval listed in Table
AC-2. Samples were driven personally to the ALS Laboratory in Brisbane, QLD
who composited the core samples for metallurgical testing. The composite was
air-freighted from Brisbane to ALS Perth laboratory.
Audits or reviews · The results of any audits or reviews of sampling techniques and · No external audits or reviews have yet been undertaken.
data.
Drill sample recovery
· Method of recording and assessing core and chip sample recoveries
and results assessed.
· Measures taken to maximise sample recovery and ensure
representative nature of the samples.
· 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.
· Not applicable in this study, no new holes completed.
Historical drillholes, including BH1 used for this study were documented to
have >90% core recovery.
Logging
· Whether core and chip samples have been geologically and
geotechnically logged to a level of detail to support appropriate Mineral
Resource estimation, mining studies and metallurgical studies.
· Whether logging is qualitative or quantitative in nature. Core
(or costean, channel, etc) photography.
· The total length and percentage of the relevant intersections
logged.
· The drilling that did occur was generally completed to modern-day
standards. The preferred exploration strategy in the eighties and early
nineties was to drill shallow auger holes to negate the influence of any
Quaternary and Tertiary thin cover.
· No downhole geophysical logging took place; however, measurements
of magnetic susceptibility were taken on the six-library core relogged over
the same intervals as the PXRF readings were taken.
Sub-sampling techniques and sample preparation
· If core, whether cut or sawn and whether quarter, half or all
core taken.
· If non-core, whether riffled, tube sampled, rotary split, etc and
whether sampled wet or dry.
· For all sample types, the nature, quality, and appropriateness of
the sample preparation technique.
· Quality control procedures adopted for all sub-sampling stages to
maximise representivity of samples.
· Measures taken to ensure that the sampling is representative of
the in-situ material collected, including for instance results for field
duplicate/second-half sampling.
· Whether sample sizes are appropriate to the grain size of the
material being sampled.
· The preliminary rougher testwork methodology employed is listed
as follows:
Given the bulk concentrate methodology requested, recovery would take priority
over the grade at this stage. Initially, two different reagent schemes for the
bulk con generation:
• Natural pH, PAX, Danafloat 245; (PAX may cause high iron
collection)
• Cytec aero float, Aero 3894 with an Aero 208 promoter
The final recommendation was to try initially 10g/t of the danafloat / aero
208, with 5g/t of the PAX or Aero 3894. Consideration was also given to add
additional dosage at the end of the first 3 concentrates (assumed 2-minute Ro
concentrate), and then see if more product reports into Ro Con 4.
Eventually, a series of rougher tests (refer to Table AC1-1) were carried out
based on the following methodology:
Sample Preparation and Screening Analysis
• Receive Samples and Inventory
• Control Crush P100 3.35mm (assumed no compositing)
• Rotary Blending & Splitting 1kg charges (12 x 1kg)
• PPS - Head Assay Submission
• Assay - Head Sample (Ag, Au, Co, Cu, SiO2, S, ICP Scan)
Flotation and Gravity Testing
• 1 kg Grind Establishment Single grind target
• Rougher Flotation (4 con 1 tail) (5 test allowance)
• PPS - Flotation Product Assay Submission
• Assay - Flotation Products (Ag, Au, Co, Cu, Zn, SiO2)
• Gravity Separation - Wilfley Table - Batch Test
• PPS - Table Product Assay Submission
• Assay - Table Products (Ag, Au, Co, Cu, Zn, SiO2, S)
Quality of assay data and laboratory tests
· The nature, quality and appropriateness of the assaying and
laboratory procedures used and whether the technique is considered partial or
total.
· 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.
· Nature of quality control procedures adopted (eg standards,
blanks, duplicates, external laboratory checks) and whether acceptable levels
of accuracy (i.e. lack of bias) and precision have been established.
· The samples in the composite were originally analysed at the ALS
Brisbane Laboratory using the ME-MS61R technique, as summarised below:
Inductively Coupled Plasma - Atomic Emission Spectroscopy (ICP - AES)
Inductively Coupled Plasma - Mass Spectrometry (ICP-MS)
Sample Decomposition is by HF-HNO(3)-HClO(4) acid digestion, HCl leach
(GEO-4A01).
A prepared sample (0.25 g) is digested with perchloric, nitric, hydrofluoric,
and hydrochloric acids. The residue is topped up with dilute hydrochloric acid
and analyzed by inductively coupled plasma atomic emission spectrometry.
Following this analysis, the results are reviewed for high concentrations of
bismuth, mercury, molybdenum, silver, and tungsten and diluted accordingly.
Samples meeting this criterion are then analyzed by inductively coupled
plasma-mass spectrometry. Results are corrected for spectral interelement
interferences.
NOTE: Four acid digestions can dissolve most minerals; however, although the
term "near total" is used, depending on the sample matrix, not all elements
are quantitatively extracted.
Results for the additional rare earth elements will represent the acid
leachable portion of the rare earth elements and as such, cannot be used, for
instance to do a chondrite plot.
· Laboratory inserted standards, blanks and duplicates were
analysed per industry standard practice. There was no evidence of bias from
these results.
Verification of sampling and assaying
· The verification of significant intersections by either
independent or alternative company personnel.
· The use of twinned holes.
· Documentation of primary data, data entry procedures, data
verification, data storage (physical and electronic) protocols.
· Discuss any adjustment to assay data.
· None of the library drillholes (including BH1) have been twinned,
as they are historical holes
.
· The four preliminary rougher tests results have been reproduced
in full in Appendix 1 of this ASX release.
Location of data points
· Accuracy and quality of surveys used to locate drill holes
(collar and down-hole surveys), trenches, mine workings and other locations
used in Mineral Resource estimation.
· Specification of the grid system used.
· Quality and adequacy of topographic control.
· In general, locational accuracy does vary, depending upon whether
the samples were digitised off plans or had their coordinated tabulated.
Many samples were reported to AGD66 or AMG84 and have been converted to
MGA94.Zone 54
· It is estimated that locational accuracy of BH1 therefore varies
between 2-50m
Data spacing and distribution
· Data spacing for reporting of 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.
· Whether sample compositing has been applied.
· The average sample spacing across the tenure varies per prospect,
and sample type, as listed in Table AB1-2, below:
Table AB-2: EL 8434 and EL 8435 Drillhole Spacing
Prospect Drillholes in Model RMS Drillhole Spacing (m)
The Sisters 12 242
Rothwell 1 N/A
Round Hill 1 N/A
Iron Blow 8 315
Avondale East 24 134.2
Tors Tank 342 27.4
Fence Gossan 549 25.5
Ziggy's Hill 245 37.0
Reefs Tank 1,375 22.1
· No sample compositing has been applied to any results in this
release..
Orientation of data in relation to geological structure
· Whether the orientation of sampling achieves unbiased sampling of
possible structures and the extent to which this is known, considering the
deposit type.
· 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.
· The current database does not contain any sub-surface geological
logging for Avondale East , which is being compiled (75% complete)
· Geological mapping by various companies has reinforced that the
strata is tightly folded, dips variously between 45 and 80 degrees, and dips
mostly to the north and northwest.
Sample security
· The measures taken to ensure sample security.
· The sample security measures, except for the Squadron Resources
work programs is not known. Squadron took samples to their Broken Hill
office and transported samples for analysis to ALS Broken Hill. Castillo
Copper contractors relogged BH1 and used a diamond saw to sample and bag
prospective intervals within the hole including that interval listed in Table
AC-2. Samples were driven personally to the ALS Laboratory in Brisbane, QLD
who composited the core samples for metallurgical testing. The composite was
air-freighted from Brisbane to ALS Perth laboratory.
Audits or reviews
· The results of any audits or reviews of sampling techniques and
data.
· No external audits or reviews have yet been undertaken.
Table AC1-1: The Sisters Metallurgical Testing Parameters
COMPOSITE The Sisters BH1 The Sisters BH1 The Sisters BH1 The Sisters BH1
TEST # BF2270 BF2271 BF2291 BF2293
WATER TYPE Perth Tap Water Perth Tap Water Perth Tap Water Perth Tap Water
REAGENT Danafloat AeroFloat Danafloat Danafloat
GRIND SIZE P80 75µm P80 75µm P80 75µm P80 25µm
PULP DENSITY 35% 35% 35% 35%
pH 5.9 5.7 11.0 11.0
Figure AC1-1: The Sisters Sample and Drillhole location, and Cobalt Histogram
Table AC1-2: The Sisters Sample for Metallurgical Testing
Drillhole XRF Samp SampleID From To Length (m) Weight (kg) Ag_ppm Co_ppm Cu_ppm Ag Mass Co Mass Cu Mass
BH1 BH1.18 CCZ03785 103.07 104.73 1.66 0.65 0.32 712 483 0.01 28.44 19.30
BH1 BH1.19 CCZ03786 104.73 106.62 1.89 0.84 0.2 450 773 0.01 23.23 39.91
BH1 BH1.20 CCZ03787 106.62 108.51 1.89 0.94 0.29 1120 1260 0.02 64.71 72.80
BH1 BH1.21 CCZ03788 108.51 110.46 1.95 1.54 0.04 93.5 90.1 0.00 8.85 8.53
BH1 BH1.22 CCZ03789 110.46 112.41 1.95 1.75 0.05 23.3 167 0.01 2.51 17.96
BH1 BH1.23 CCZ03790 112.41 114.36 1.95 2.08 0.04 112.5 23.9 0.01 14.38 3.06
BH1 BH1.24 CCZ03791 114.36 116.31 1.95 1.66 0.15 62.6 33.5 0.02 6.39 3.42
BH1 BH1.25 CCZ03792 116.31 118.26 1.95 0.81 0.15 409 235.0 0.01 20.36 11.70
BH1 BH1.26 CCZ03793 118.26 119.29 1.03 0.71 0.13 419 233.0 0.01 18.28 10.17
BH1 BH1.27 CCZ03794 119.29 120.32 1.03 0.72 0.08 759 56.8 0.00 33.59 2.51
BH1 BH1.28 CCZ03795 120.32 121.35 1.03 0.7 0.33 873 196.5 0.01 37.56 8.45
BH1 BH1.29 CCZ03796 121.35 122.38 1.03 0.84 0.04 111 72.7 0.00 5.73 3.75
BH1 BH1.30 CCZ03797 122.38 123.44 1.06 0.72 0.77 193 73.6 0.03 8.54 3.26
BH1 BH1.31 CCZ03798 123.44 124.66 1.22 0.69 0.46 477 385 0.02 20.23 16.33
BH1 BH1.32 CCZ03799 124.66 125.88 1.22 0.7 1.18 727 10650 0.05 31.28 458.21
BH1 BH1.33 CCZ03800 125.88 127.10 1.22 0.92 0.49 245 4280 0.03 13.85 242.02
24.03 16.27 0.23 338 921
SECTION 2 REPORTING OF EXPLORATION RESULTS
(Criteria listed in the preceding section also apply to this section.)
Criteria JORC Code explanation Commentary
Mineral tenement and land tenure status · Type, reference name/number, location and ownership including EL 8434 is located about 28km east of Broken Hill whilst EL 8435 is 16km east
agreements or material issues with third parties such as joint ventures, of Broken Hill. Both tenures are approximately 900km northwest of Sydney in
partnerships, overriding royalties, native title interests, historical sites, far western New South Wales (Figure A1-2-1).
wilderness or national park and environmental settings.
EL 8434 and EL 8435 were both granted on the 2(nd of) June 2016 to Squadron
· The security of the tenure held at the time of reporting along Resources for a term of five (5) years for Group One Minerals. On the 25(th
with any known impediments to obtaining a licence to operate in the area. of) May 2020, Squadron Resources changed its name to Wyloo Metals Pty Ltd
(Wyloo). In December 2020 the tenure was transferred from Wyloo Metals to
Broken Hill Alliance Pty Ltd a 100% subsidiary company of Castillo Copper
Limited. Both tenures were renewed on the 12(th of) August 2021 for a
further six (6) years and are due to expire on the 2(nd of) June 2027.
EL 8434 lies across two (2) 1:100,000 geology map sheets Redan 7233 and
Taltingan 7234, and two (2) 1:250,000 geology map sheets, SI54-3 Menindee, and
SH54-15 Broken Hill in the county of Yancowinna. EL 8434 consists of one
hundred and eighty-six (186) units) in the Adelaide and Broken Hill
1:1,000,000 Blocks covering an area of approximately 580km(2).
EL 8435 is located on the 1:100,000 geology map sheet Taltingan 7234, and the
1:250,000 geology map sheet SH/54-15 Broken Hill in the county of
Yancowinna. EL 8435 consists of twenty-two (22) units (Table 1) in the
Broken Hill 1:1,000,000 Blocks covering an area of approximately 68km(2).
Access to the tenures from Broken Hill is via the sealed Barrier Highway.
This road runs north-east to south-west through the northern portion of the EL
8434, passes the southern tip of EL 8435 eastern section and through the
middle of the western section of EL 8435. Access is also available via the
Menindee Road which runs north-west to south-east through the southern section
of the EL 8434. The Orange to Broken Hill Rail line also dissects EL 8435
western section the middle and then travels north-west to south-east slicing
through the eastern arm of EL 8434 (Figure AC-2-1).
Figure AC2-1: EL 8434 and EL 8434 General Location Map
Exploration done by other parties · Acknowledgment and appraisal of exploration by other parties. Explorers who were actively involved over longer historical periods in various
parts of EL8434 were: - North Broken Hill Ltd, CRAE Exploration, Major Mining
Ltd and Broken Hill Metals NL, Pasminco Exploration Ltd, Normandy Exploration
Ltd, PlatSearch NL/Inco Ltd/ EGC Pty Ltd JV and the Western Plains Gold
Ltd/PlatSearch/EGC Pty Ltd JV.
A comprehensive summary of work by previous explorers was presented in Leyh
(2009). However, more recently, follow-up field reconnaissance of areas of
geological interest, including most of the prospective zones was carried out
by EGC Pty Ltd over the various licenses. This work, in conjunction with a
detailed interpretation of aeromagnetic, gravity plus RAB / RC drill hole
logging originally led to the identification of at least sixteen higher
priority prospect areas. All these prospects were summarized in considerable
detail in Leyh (2008). Future work programs were then also proposed for each
area. Since then, further compilation work plus detailed geological
reconnaissance mapping and sampling of gossans and lode rocks has been carried
out.
A total of 22 prospects were then recognised on the exploration licence with
at least 12 occurring in and around the tenure.
With less than 15% outcropping Proterozoic terrain within the licence, this
makes it very difficult to explore and is in the main very effectively
screened from the easy application of more conventional exploration
methodologies due to a predominance of extensive Cainozoic cover sequences.
These include recent to young Quaternary soils, sands, clays and older more
resistant, only partially dissected, Tertiary duricrust regolith covered
areas. Depth of cover ranges from a few metres in the north to over 60
metres in some areas on the southern and central license.
Exploration by EGC Pty Ltd carried out in the field in the first instance has
therefore been heavily reliant upon time consuming systematic geological
reconnaissance mapping and relatable geochemical sampling. These involve a
slow systematic search over low outcropping areas, poorly exposed subcrops and
float areas as well as the progressive development of effective regolith
mapping and sampling tools. This work has been combined with a vast amount
of intermittently acquired past exploration data. The recent data
compilation includes an insufficiently detailed NSWGS regional mapping scale
given the problems involved, plus some regionally extensive, highly variable,
low-level stream and soil BLEG geochemical data sets over much of the area.
There are also a few useful local detailed mapping grids at the higher
priority prospects, and many more numerous widespread regional augers, RAB,
and percussion grid drilling data sets. Geophysical data sets including ground
magnetics, IP and EM over some prospect areas have also been integrated into
the exploration models. These are located mainly in former areas of moderate
interest and most of the electrical survey methods to date in this type of
terrain continue to be of limited application due to the high degree of
weathering and the often prevailing and complex regolith cover constraints.
Between 2007 and 2014 Eaglehawk Geological Consulting has carried out detailed
research, plus compilation and interpretation of a very large volume of
historic exploration data sourced from numerous previous explorers and dating
back to the early 1970's. Most of this data is in non-digital scanned form.
Many hard copy exploration reports (see references) plus several hundred plans
have been acquired from various sources, hard copy printed as well as
downloaded as scans from the Geological Survey of NSW DIGS system. They also
conducted field mapping, costean mapping and sampling, and rock chip sampling
and analysis.
Work Carried out by Squadron Resources and Whyloo Metals 2016-2020
Research during Year 1 by Squadron Resources revealed that the PGE-rich,
sulphide-bearing ultramafic rocks in the Broken Hill region have a
demonstrably alkaline affinity. This indicates a poor prospectivity for
economic accumulations of sulphide on an empirical basis (e.g., in comparison
to all known economic magmatic nickel sulphide deposits, which have a
dominantly tholeiitic affinity). Squadron instead directed efforts toward
detecting new Broken Hill-Type (BHT) deposits that are synchronous with basin
formation. Supporting this modified exploration rationale are the EL's
stratigraphic position, proximity to the Broken Hill line of lode, abundant
mapped alteration (e.g., gahnite and/or garnet bearing exhalative units) and
known occurrences such as the "Sisters" and "Iron Blow" prospects.
The area overlies a potential magmatic Ni-Cu-PGE source region of
metasomatised sub-continental lithospheric mantle (SCLM) identified from a
regional targeting geophysical data base. The exploration model at the time
proposed involved remobilization of Ni-Cu-PGE in SCLM and incorporation into
low degree mafic-ultramafic partial melts during a post-Paleoproterozoic plume
event and emplacement higher in the crust as chonoliths/small intrusives -
Voisey's Bay type model. Programs were devised to use geophysics and
geological mapping to locate secondary structures likely to control and
localise emplacement of Ni-Cu-PGE bearing chonoliths. Since EL8434 was
granted, the following has been completed:
• Airborne EM survey.
• Soil and chip sampling.
• Data compilation.
• Geological and logistical reconnaissance.
• Community consultations; and
• Execution of land access agreements.
Airborne EM Survey
Geotech Airborne Limited was engaged to conduct an airborne EM survey using
their proprietary VTEM system in 2017. A total of 648.92-line kilometres
were flown on a nominal 200m line spacing over a portion of the project area.
Several areas were infilled to 100m line spacing.
The VTEM data was interpreted by Southern Geoscience Consultants Pty Ltd, who
identified a series of anomalies, which were classified as high or low
priority based on anomaly strength (i.e., does the anomaly persist into the
latest channels). Additionally, a cluster of VTEM anomalies at the "Sisters"
prospect have been classified separate due to strong IP effects observed in
the data. Geotech Airborne have provided an IP corrected data and
interpretation of the data has since been undertaken.
Soil and Chip sampling
The VTEM anomalies were followed up by a reconnaissance soil sampling
programme. Spatially clustered VTEM anomalies were grouped, and follow-up
soil lines were designed. Two (2) VTEM anomalies were found to be related to
culture and consequently no soils were collected. Two (2) other anomalies
were sampled which were located above thick alluvium of Stephens Creek and
were therefore not sampled. A line of soil samples was collected over a
relatively undisturbed section at Iron Blow workings and the Sisters Prospect.
One hundred and sixty-six (166) soil samples were collected at a nominal 20cm
depth using a 2mm aluminum sieve. Two (2) rock chips were also collected
during this program. The samples were collected at either 20m or 40m spacing
over selected VTEM anomalies. The samples were pulverised and analysed by
portal XRF at ALS laboratories in Perth.
Each site was annotated with a "Regolith Regime" such that samples from a
depositional environment could be distinguished from those on exposed
Proterozoic bedrock, which were classified as an erosional environment. The
Regolith Regime groups were used for statistical analysis and levelling of the
results. The levelled data reveals strong relative anomalies in zinc at VTEM
anomaly clusters 10, 12 and 14 plus strong anomalous copper at VTEM 17.
Geology · Deposit type, geological setting, and style of mineralisation. Regional Geology
The Broken Hill polymetallic deposits are located within Curnamona Province
(Willyama Super group) (Figure A3-2-2) that hosts several world-class deposits
of lead, zinc, silver, and copper. The Willyama Supergroup consists of
highly deformed metasedimentary schists and gneisses with abundant
quartz-feldspathic gneisses, lesser basic gneisses, and minor 'lode' rocks
which are quartz-albite and calc-silicate rocks (Geoscience Australia,
2019). Prograde metamorphism ranges from andalusite through sillimanite to
granulite grade (Stevens, Barnes, Brown, Stroud, & Willis, 1988).
Regionally, the tenures are situated in Broken Hill spatial domain which
extends from far western New South Wales into eastern South Australia. The
Broken Hill Domain hosts several major fault systems and shear zones, which
were formed by various deformation events and widespread metamorphism which
has affected the Willyama Supergroup (Figure A1-2-3). Major faults in the
region include the Mundi Mundi Fault to the west of Broken Hill, the Mulculca
Fault to the east, and the Redan Fault to the south. Broken Hill is also
surrounded by extensive shear zones including the Stephens Creek,
Globe-Vauxhall, Rupee, Pine Creek, Albert, and Thackaringa-Pinnacles Shear
Zones.
Figure B2: Regional Stratigraphy
Modified after: (Stevens, Barnes, Brown, Stroud, & Willis, 1988)
Figure B3: Regional Geological Map
Modified after (Peljo, 2003)
There are over twenty (20) rock formations mapped within the project area.
Parts of the project area are covered by Quaternary alluvium, sands, and by
Tertiary laterite obscuring the basement geology. Within the Lower to Middle
Proterozoic Willyama Supergroup (previously Complex) there are two (2) groups,
the Thackaringa Group, and the younger Broken Hill Group (Colquhoun, et al.,
2019).
Local Geology
A summary of the units that host or appear to host the various mineralisation
styles within EL 8434 and EL 8435 is given below.
Broken Hill Group
The Hores Gneiss is mostly comprised of quartz-feldspar-biotite-garnet gneiss,
interpreted as metadacite with some minor metasediments noted. An age range
from Zircon dating has been reported as 1682-1695Ma (Geoscience Australia,
2019). The Allendale Metasediments unit contains mostly metasedimentary
rocks, dominated by albitic, pelitic to psammitic composite gneiss, including
garnet-bearing feldspathic composite gneiss, sporadic basic gneiss, and
quartz-gahnite rock. Calc-silicate bodies can be found at the base of the
unit and the formation's average age is 1691 Ma (Geoscience Australia, 2019).
Thackaringa Group
The Thorndale Composite Gneiss is distinguished by mostly gneiss, but also
migmatite, amphibolite, and minor magnetite. The age of this unit is
>1700Ma (Geoscience Australia, 2019) and is one of the oldest formations in
the Group. The Cues Formation is interpreted as a deformed sill-like
granite, including Potosi-type gneiss. Other rock-types include pelitic
paragneiss, containing cordierite. The average age: ca 1700-1730 Ma.
(Stevens, Barnes, Brown, Stroud, & Willis, 1988). Other rock types
include mainly psammo-pelitic to psammitic composite gneisses or
metasedimentary rocks, and intercalated bodies of basic gneiss. This unit is
characterised by stratiform horizons of granular garnet-quartz +/-magnetite
rocks, quartz-iron oxide/sulphide rocks and quartz-magnetite rocks (Geoscience
Australia, 2019). This is a significant formation as it hosts the Pinnacles
Ag-Pb-Zn massive sulphide deposit along with widespread Fe-rich stratiform
horizons.
The protolith was probably sandy marine shelf sedimentary rocks. An
intrusion under shallow cover was syn-depositional. The contained
leuco-gneisses and Potosi-type gneisses are believed to represent a felsic
volcanic or volcaniclastic protolith. Basic gneisses occur in a substantial
continuous interval in the middle sections of the Formation, underlain by
thinner, less continuous bodies. They are moderately Fe-rich (abundant
orthopyroxene or garnet) and finely layered, in places with pale feldspar-rich
layers, and are associated with medium-grained quartz-feldspar-biotite-garnet
gneiss or rock which occurs in thin bodies or pods ('Potosi-type' gneiss).
A distinctive leucocratic quartz-microcline-albite(-garnet) gneiss
(interpreted as meta-rhyolite) occurs as thin, continuous, and extensive
horizons, in several areas. The sulphide-bearing rocks may be lateral
equivalents of, or associates of Broken Hill type stratiform mineralisation.
Minor layered garnet-epidote-quartz calc-silicate rocks occur locally within
the middle to basal section. The unit is overlain by the Himalaya
Formation.
Cues Formation
The Cues Formation is intruded by Alma Granite (Geoscience Australia, 2019).
The Himalaya Formation (Figure A3-2-4) consists of medium-grained saccharoidal
leucocratic psammitic and albitic meta-sedimentary rocks (average age
1700Ma). The unit comprises variably interbedded albite-quartz rich rocks,
composite gneiss, basic gneiss, horizons of thinly bedded quartz-magnetite
rock. Pyrite-rich rocks occur at the base of the formation (Geoscience
Australia, 2019). It is overlain by the Allendale Metasediments (Broken Hill
Group). The Himalaya Formation hosts cobalt-rich pyritic horizons at Pyrite
Hill and Big Hill. The protolith is probably sandy marine shelf sedimentary
rocks with variable evaporitic or hypersaline component. Plagioclase-quartz
rocks are well-bedded (beds 20 - 30mm thick), with rare scour-and-fill and
cross-bedded structures.
Thin to thick (0.5 - 10m) horizons of thinly bedded quartz-magnetite rock also
occur with the plagioclase-quartz rocks. In some areas the formation
consists of thin interbeds of plagioclase-quartz rocks within meta-sedimentary
rocks or metasedimentary composite gneiss (Geoscience Australia, 2019). Lady
Brassey Formation which is well-to-poorly-bedded leucocratic sodic
plagioclase-quartz rock, as massive units or as thick to thin interbeds within
psammitic to pelitic metasedimentary composite gneisses. A substantial
conformable basic gneiss. It overlies both Mulculca Formation and Thorndale
Composite Gneiss. Part of the formation was formerly referred to as Farmcote
Gneiss in the Redan geophysical zone of Broken Hill Domain - a zone in which
the stratigraphy has been revised to create the new Rantyga Group (Redan and
Ednas Gneisses, Mulculca Formation, and the now formalised Farmcote Gneiss).
Lady Louise Suite
This unit is approximately 1.69Ma in age comprising amphibolite,
quartz-bearing, locally differentiated to hornblende granite, intrusive sills,
and dykes, metamorphosed, and deformed; metabasalt with pillows (Geoscience
Australia, 2019). Annadale Metadolerite is basic gneisses, which includes
intervening metasedimentary rocks possibly dolerite (Geoscience Australia,
2021).
Rantya Group
Farmcote Gneiss contains metasedimentary rocks and gneiss and is a new unit at
the top of Rantyga Group. It is overlain by the Cues Formation and
Thackaringa Group, and it overlies the Mulculca Formation. The age of the
unit is between 1602 to 1710Ma. Mulculca Formation is abundant
metasedimentary composite gneiss, variable sodic plagioclase-quartz-magnetite
rock, quartz-albite-magnetite gneiss, minor quartz-magnetite rock common,
minor basic gneiss, albite-hornblende-quartz rock (Geoscience Australia,
2019). Ednas Gneiss contains quartz-albite-magnetite gneiss, sodic
plagioclase-quartz-magnetite rock, minor albite-hornblende-quartz rock, minor
quartzo-feldspathic composite gneiss. It is overlain by Mulculca Formation.
Silver City Suite
Formerly mapped in the Thackaringa Group this new grouping accommodates the
metamorphosed and deformed granites. A metagranite containing
quartz-feldspar-biotite gneiss with variable garnet, sillimanite, and
muscovite, even-grained to megacrystic, elongate parallel to enclosing
stratigraphy. It occurs as sills and intrudes both the Thackeringa Group and
the Broken Hill Group. This unit is aged between 1680 to 1707Ma.
Torrowangee Group
Mulcatcha Formation comprises flaggy, quartzose sandstone with lenticular
boulder and arkosic sandstone beds. Yangalla Formation contains boulder
beds, lenticular interbedded siltstone, and sandstone. It overlies the
Mulcatcha Formation (Geoscience Australia, 2020).
Sundown Group
The Sundown Group contains Interbedded pelite, psammopelitic and psammitic
metasedimentary rocks and it overlies the Broken Hill Group. The unit age is
from 1665 to 1692Ma (Figure A1-2-4).
There is also an unnamed amphibolite in Willyama Supergroup, which present
typically medium grained plagioclase and amphibole or pyroxene rich stratiform
or discordant dykes.
Figure B4: EL 8434 and EL 8435 Solid Geology
Drill hole Information · A summary of all information material to the understanding of the · No new drillholes have been completed yet, but a small RC and
exploration results including a tabulation of the following information for diamond core drilling program across all the modelled prospects (The Sisters,
all Material drill holes: Fence Gossan, Tors Tank, and Reefs Tank) is planned
o easting and northing of the drill hole collar
o elevation or RL (Reduced Level - elevation above sea level in metres) of
the drill hole collar
o dip and azimuth of the hole
o down hole length and interception depth
o hole length.
· If the exclusion of this information is justified on the basis
that the information is not Material and this exclusion does not detract from
the understanding of the report, the Competent Person should clearly explain
why this is the case.
Data aggregation methods · In reporting Exploration Results, weighting averaging techniques, · No metal equivalents have been reported. Where rare earth
maximum and/or minimum grade truncations (e.g., cutting of high grades) and element results have been reported, they have been converted to rare earth
cut-off grades are usually Material and should be stated. oxides as per standard industry practice.
· Where aggregate intercepts incorporate short lengths of · No compositing of any of the metallurgical results has taken
high-grade results and longer lengths of low-grade results, the procedure used place
for such aggregation should be stated and some typical examples of such
aggregations should be shown in detail. · No assay results have been withheld from the metallurgical test
work.
· The assumptions used for any reporting of metal equivalent values
should be clearly stated.
Relationship between mineralisation widths and intercept lengths · These relationships are particularly important in the reporting · As a database of all the historical borehole sampling has not yet
of Exploration Results. been completed and validated (in progress) it is uncertain if there is a
relationship between the surface sample anomalies to any subsurface anomalous
intersections. Mineralisation is commonly associated with shears, faults,
amphibolites, and pegmatitic intrusions within the shears, or on or adjacent
· If the geometry of the mineralisation with respect to the drill to the boundaries of the Himalaya Formation.
hole angle is known, its nature should be reported.
· Geological 3D models - sufficient data was available to generate
· If it is not known and only the down hole lengths are reported, a small - moderate resource of cobalt with copper credits, which has been
there should be a clear statement to this effect (e.g., 'down hole length, completed and reported in June 2022 in an ASX release.
true width not known').
Diagrams · Appropriate maps and sections (with scales) and tabulations of · Current surface anomalies are shown on maps in the report in
intercepts should be included for any significant discovery being reported previous ASX releases. All historical surface sampling has had their
These should include, but not be limited to a plan view of drill hole collar coordinates converted to MGA94, Zone 54.
locations and appropriate sectional views.
Balanced reporting · Where comprehensive reporting of all Exploration Results is not · All results from the recent preliminary rougher flotation trials
practicable, representative reporting of both low and high grades and/or have been included as Appendix B in this release.
widths should be practiced to avoid misleading reporting of Exploration
Results.
Other substantive exploration data · Other exploration data, if meaningful and material, should be · Historical explorers have also conducted airborne and ground
reported including (but not limited to): geological observations; geophysical gravity, magnetic, EM, and IP resistivity surveys over parts of the tenure
survey results; geochemical survey results; bulk samples - size and method of area but these are yet to be fully georeferenced (especially the ground IP
treatment; metallurgical test results; bulk density, groundwater, geotechnical surveys).
and rock characteristics; potential deleterious or contaminating substances.
Further work · The nature and scale of planned further work (e.g., tests for It is recommended that:
lateral extensions or depth extensions or large-scale step-out drilling).
· The non-sampled zones within the Core Library drillholes, BH1,
BH2, and DD90-IB3 in the north of the tenure group be recovered, sampled, and
analysed.
· Diagrams clearly highlighting the areas of possible extensions,
including the main geological interpretations and future drilling areas, · That a more detailed study of historical drillholes should be
provided this information is not commercially sensitive. conducted to determine if enough data exists at Iron Blow and Avondale East to
estimate a JORC resource.
· That a program of field mapping and ground magnetic or EM surveys
be planned and executed; and
· A program of exploration RC drilling be planned across all the
model areas, except for Ziggy's Hill. Consideration should be given to
coring at least one of the holes.
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