REG - Castillo Copper Ltd - Cangai MRE: 4.6Mt @ 2.45% Cu for ~114kt copper
25/07/2023 07:00
For best results when printing this announcement, please click on link below:
http://newsfile.refinitiv.com/getnewsfile/v1/story?guid=urn:newsml:reuters.com:20230725:nRSY0055Ha&default-theme=true
RNS Number : 0055H Castillo Copper Limited 25 July 2023
25 July 2023
CASTILLO COPPER LIMITED
("Castillo", or the "Company")
Cangai MRE: 4.6Mt @ 2.45% Cu for ~114kt copper
Castillo Copper Limited (LSE and ASX: CCZ), a base metal explorer primarily
focused on copper across Australia and Zambia, is pleased to report the
updated JORC (2012) compliant total Mineral Resource Estimate ("MRE") for
Cangai Copper Mine which came in at 4.6Mt @ 2.5% Cu for ~114kt contained
copper metal (Figure 1). In addition, reflected in the overall MRE are zinc,
gold and silver credits that modestly boost the result (15.3g/t Ag; 0.29g/t Au
and 0.57% Zn).
HIGHLIGHTS:
· Castillo's geology team, working in conjunction with a specialist
geological consultancy, have produced an updated JORC (2012) compliant Mineral
Resource Estimate for Cangai Copper Mine at:
o 4.4Mt @ 2.5% Cu inferred insitu and 0.2Mt @ 1.35% Cu indicated from
historic stockpiles for ~114kt contained copper metal; augmented further by
zinc, gold, and silver credits
· In calculating the updated MRE from the 2017 work (MRE: 3.3Mt @ 3.35%
Cu for 108,000t(1)), the geology team factored in reverse circulation and
diamond core drilling campaigns undertaken across 2017-18 and used more
conservative assumptions to boost the confidence in the revised 2023 MRE
· The geology team noted several encouraging observations that
underpins significant exploration potential for Cangai Copper Mine, including:
o The underlying orebody - which commences from surface - is not fully
defined, as it remains open to the east, south-east and down dip
o There are several sizeable downhole electromagnetic ("DHEM") conductors,
proximal to the line of lode, that can potentially extend known mineralisation
along strike
· With the revised 2023 MRE enhancing Cangai Copper Mine's
fundamentals, the Board is highly optimistic Castillo can align with a
strategic partner to fully develop the copper potential and map out a viable
path to market
Ged Hall, Chairman of Castillo Copper, said: "Having a high-grade MRE for
circa 114kt copper metal plus significant exploration potential is an
excellent value add outcome. Moreover, when reconciling Cangai Copper Mine's
favourable fundamentals with long-term global demand trends for copper, the
Board believes it has a compelling business case to leverage and align with a
strategic development partner."
UPDATED MRE: 114,000T COPPER
In calculating the updated MRE, the geology team primarily used data from
prior drilling campaigns (including RC & diamond core work across 2017-18)
and surface channel sampling programmes to model the outcome (refer to
Appendix A).
Further, the reporting contains a small indicated MRE based on assessing
historical stockpiles which were accurately mapped by drone survey and channel
sampling (Appendix C).
Category Inferred Mass Cu Co Zn Au Ag Cu Co Zn Au Ag
(Tonnes) (%) (%) (%) (g/t) (g/t) (Tonnes) (Tonnes) (Tonnes) (Kg) (Kg)
Oxide Insitu 634,000 2.65 0.01 0.65 0.15 16.1 16,801 63 4,121 95 10,207
Fresh 3,773,000 2.48 0.01 0.55 0.31 15.2 93,570 226 20,752 1,170 57,350
Ex-Mine Oxide Dumps 29,000 2.10 0.02 0.3 0.58 14.5 609 5 87 17 421
Total 4,436,000 2.5 0.01 0.6 0.29 15.3 110,980 294 24,960 1,282 67,978
HISTORIC STOCKPILES
Category Indicated Mass Cu Co Zn Au Ag Cu Co Zn Au Ag
(Tonnes) (%) (%) (%) (g/t) (g/t) (Tonnes) (Tonnes) (Tonnes) (Kg) (Kg)
Smelter Slag and Ex-Mine Oxide Dumps 199,000 1.35 0.02 1.9 0.1 4.6 2,687 48 3,781 20 915
199,000 1.35 0.02 1.9 0.1 4.6 2,687 48 3,781 20 915
4,635,000 2.45 0.01 0.6 0.28 14.9 113,667 342 28,741 1,301 68,893
FIGURE 1: RESOURCE TONNAGES - CANGAI COPPER MINE
Notes:
1. All Resource tonnages rounded to nearest 1,000
tonnes.
2. Refer to JORC Table 1 for details on data and
estimation.
3. Insitu tonnages calculated as a guide only, no
recovery factor, loss or dilution considered.
Source: CCZ geology team
Exploration potential
A key positive for Cangai Copper Mine is the copper orebody commences from
surface. More encouragingly, the full extent of the underlying copper orebody
remains undetermined, as it remains open to the east, south-east and down
dip.
As shown in Figure 2, there are several sizeable DHEM conductors(2), which are
north and south of the line of lode, that can potentially extend known
mineralisation along strike.
FIGURE 2: DHEM CONDUCTORS AT CANGAI COPPER MINE(1,2,7)
Source: CCZ geology team
Reconciling Historical Mining with Known Facts
Mined out shapes of the various named lenses at Cangai Copper Mine represent,
according to Carne (1908)(3), mining of material >13% Cu. However, the
actual mined limit must have been lower than this, or there was some dilution,
as total copper produced was 5,080t reportedly @ 8% Cu(4). Note, this equates
to 63,500t although McQueen (2019)(4) quotes 74,600t).
Figure 3 presents an attempt to reconcile mined and remaining surficial
material from Cangai Copper Mine, based on available records.
FIGURE 3: AS-MINED RECONCILIATION(4)
Description Mass (t) Comments
Total material mined 307,000 GSNSW mining records based on information supplied by Grafton Copper Mining
Company
Material presented for smelting 235,900 Product shipped and stockpile
Ex-Mine dumps 49,000 Estimates and mapping not complete
Unaccounted for 22,000 Wasted or used for construction and other projects
Source: CCZ geology team
In Figure 4 and Figure 5 below, blocks show copper values in % (red >5% Cu)
and wireframes used to constrain the mineral resource estimate.
FIGURE 4: BLOCK MODEL DISPLAY OF MODELLED COPPER
Legend and Notes:
1. Modelled 10m x 10m x 4m blocks sub-celled to 5m x 5m x 2m blocks showing
copper content, as per legend.
2. Vertical to horizontal exaggeration 2:1.
3. View is looking from south toward the north.
Source: CCZ geology team
FIGURE 5: CANGAI MODEL BLOCKS - VISUALISATION OF COPPER RESOURCE WIREFRAMES
Notes:
1. Wireframes used for mineral resource estimate.
2. Threshold for wireframes was 0.1%Cu.
3. Vertical to horizontal exaggeration 3:1.
4. View is looking from south toward the north.
Source: CCZ geology team
Cangai Copper Mine's Exploration History
Cangai Copper Mine is within Castillo's tenements - EL8625 and EL8635 - which
cover an area of 314 sq km. Since 2017, all Castillo's exploration effort has
been directed toward Cangai Copper Mine and associated stockpiles. In 1901,
the Cangai Copper Mine was discovered, with production materializing between
1904-17 and 1934-37 - initially only ore greater than 13% Cu was extracted
using manual techniques(5).
During its lifecycle, Cangai Copper Mine (Figure 6) produced 5,080t of copper
(mentioned above), 1,035kg of silver and 527kg of gold from a total
underground extraction of 307,000t(4.6). Of this, circa 63,500t was ore (which
equates to 8% Cu, 1.5g/t Au and 15g/t Ag according to GSNSW's Minview
portal(4,6)).
FIGURE 6: LOCATION OF THE CANGAI COPPER MINE
Source: CCZ geology team
During the last century, two groups undertook geological work at the Cangai
Copper Mine(5):
· Western Mining conducted geological tests in the early 1980s and
drilled one unsuccessful drill-hole before relinquishing the tenement in 1984.
· CRA Exploration (CRAE; now part of Rio Tinto) conducted geological
tests in 1990-92 and concluded Western Mining drilled in the wrong location.
Interestingly, CRAE stated "that there is potential for further economic
mineralisation" but relinquished the tenement in 1992, as Australia was in a
deep recession and base metal prices were depressed.
In geological terms, structurally controlled epigenetic copper mineralisation
is found in multiple breccia zones in an otherwise monotonous dacitic tuff,
associated with felsic dykes. There are hints of similar, en-echelon
structures nearby. A high-grade supergene zone is dominated by malachite and
azurite. Below the base of complete oxidization, there is fresh mineralised
rock dominated by chalcopyrite, bornite, and minor sphalerite(6).
After an extensive surface mapping exercise, old mine workings have been
resurveyed and georeferenced to the MGA94 Z56 datum, shifting the previously
estimated (early 2017) locations of mine plans 40 to 60m to the north and
north-east.
Figure 7 highlights all drilling undertaking historically and by Castillo
across 2017-18.
FIGURE 7: CANGAI DEPOSIT - LINE OF LODE & NOTABLE 2018 DRILL
INTERCEPTS(1,2,7)
Source: CCZ geology team
MINERAL RESOURCE ESTIMATION
ROM Resources has completed a MRE for Cangai Copper Mine, located in northern
New South Wales, using all available historic assay data as of 31 May 2023.
The MRE was classified in accordance with the Australasian Code for Reporting
of Exploration Results, Mineral Resources and Ore Reserves (JORC Code, 2012).
Castillo's Competent Person has consented to the release of the attached
mineral resource statement and has provided the following Appendices as
required under the JORC 2012 code:
Appendix A: Cangai Copper Mine Drill-hole Data
Appendix B: Geological Model Report
Appendix C: Ex-Mine and Stockpile Resource Inventory
Appendix D: JORC Table 1
ASSUMPTIONS AND METHODOLOGY
This MRE for Cangai Copper Mine is based upon several factors and assumptions:
· All the available historical drilling data as of 31 May 2023 was used
for the MRE. The data was restricted to surface drilling and underground face
sampling as recorded on historical copper mining records (specifically, Carne
1908). The drilling data was collected between 1972 -2018 by numerous
operating companies as detailed in Appendix D - JORC Table 1.
· Mineralisation outlines were interpreted using historical mine plans,
geological interpretations, and sectional views of the downhole assays above a
grade threshold of 0.1% Cu (refer to Figure 5).
· Inverse Distance Squared (IVD2) estimation was used to estimate Ag
(ppm), Au (ppm), Cu (ppm), Co (ppm), In (ppm), and Zn (ppm), using variogram
parameters defined from the drilling and historical mine workings data.
· Top cuts were applied only to mine channel samples during the
estimation to Cu (15%) to remove skewing of the grade estimations in the
supergene zone.
· The Mineral Resource has been depleted using a 3D void model of
recorded historical underground development and stopes dated 1917.
· The MRE parameters do not assume any mining methods at this stage.
· Mineral Resource classification was based principally on historical
mine records, geological re-interpretation of the mineralised lodes,
geological confidence, drill-hole spacing and grade continuity from available
drilling data.
GEOLOGY & GEOLOGICAL INTERPRETATION
Mineralisation in the Coffs Harbour Block is generally associated with fine
grained, siliceous metasediment, quartz magnetite or jasper. At Cangai Copper
Mine, mineralisation is associated with Silurian-Devonian andesite, cherty
tuff, mudstone, siltstones, lithic wackes and conglomerates of the Willowie
Creek Beds(7).
Mineralisation in other deposits in the region is interpreted to be associated
with tholeiitic volcanism in a submarine environment. However, at Cangai
Copper Mine, lead isotope studies indicate the mineralising fluids might be
related to the Towgon Grange Granodiorite intrusion(7).
The Cangai copper load was discovered accidently by J. Sellars in August 1901
whilst hunting. He identified blue-green carbonates outcropping on the highest
point of a large rock. The first shaft was sunk near this point of discovery
and 80t of oxidised ore was raised yielding from 22-34% copper grades.
Further lodes and mining took place and was sold to the Cangai Copper Mining
Company who initially extracted 300 tons of ore, which was despatched to
Newcastle and Melbourne (Wikipedia 2023; McQueen 2019)(7).
SAMPLING AND SUB-SAMPLING TECHNIQUES
Analysing surface samples was all historical from the period 1967-2018. The
data was a combination of NSW Geological Survey surface sampling database,
historical annual / relinquishment reports revisited, and additional data
extracted. Further analyses were encoded from a 1991 UNSW Honours Thesis
(Brauhart 1991)(7), while nearly 1,140 sample analyses from stream sediment,
soil, and rock chip sources were collated and combined.
All the analyses bar a few (<75 out of 5,498) samples were laboratory
tested in various NATA registered laboratories throughout Australia. Many of
the earlier CRA Exploration stream sediment and soil samples were analysed by
CRA internal laboratories7.
Many of the sampling programmes, especially from the 1990s did include
reference samples and duplicate analyses and other forms of QA/QC checking.
However, sampling prior to 1985 generally has higher "below detection limits"
and less QA/QC checks(7).
Regarding historical cores from holes held by the NSW Geological Survey at the
Cangai Copper Mine (closed), selected sections were re-analysed for check
sampling purposes using pXRF in June 2017. The grades quoted for historically
cored intervals described in various ASX releases have been measured using a
handheld pXRF Analyser. These grades are indicative grades only as the pXRF
Analyser does not have the same degree of accuracy as laboratory generated
results. During the period 14-15 August 2017, samples subjected to the pXRF
testing and some additional intervals where sulphide mineralisation was
recognised were selected and the remaining core cut for laboratory testing(7).
Samples from the 2017-2018 Cangai drilling programme were collected using the
reverse circulation method of drilling on a 1m basis. Initially 20-25kg of
chips and dust was collected and riffled down to a 1-2kg sample for further
lab analysis(7).
All samples were delivered to ALS Laboratory in either Orange NSW or Brisbane
QLD where the laboratory undertook the splitting and compositing of the 5m
composite samples and undertakes multi-element analysis on the 1m and 5m
composite samples. The 1m samples were sent to ALS Brisbane for a suite of
major oxide and trace element determinations as described in later
sections(7).
DRILLING TECHNIQUES
Historical drilling was a combination of RC with limited diamond cored holes.
A total of nine holes were completed by three different explorers for a total
of 2,075m, of which 1,991m was diamond cored at NQ and HQ diameters(7).
The two-stage drilling programme started in December 2017 and completed in
August 2018. A total of thirty-six drill-holes were completed, with all but
two were drilled using reverse circulation methods. A total of 5,257.5m was
drilled of which 178.22m was cored at a HQ diameter (61mm) in two diamond
holes (CC0035D and CC0036D). The holes were surveyed by the drilling company
(Budd Drilling) using an Eastman downhole survey camera. Post drilling the
hole collars were surveyed by DGPS survey methods by a local surveyor with
errors between the initial GPS coordinates and the final survey of ± 7m(7).
CHANNEL SAMPLES
Complementing the RC and diamond-cored holes was the use of 78 surface and
underground channel samples. The surface samples were taken by either CRAE
or Castillo by hand sampling across the width of adit or tunnel entries,
collecting a minimum of 10kg, up to 25kg.
The second dataset of underground mine channel samples was digitised off mine
plans provided by the Grafton Copper Mining Company Limited between 1908-1914.
This data represents hand sampled intervals perpendicular to the width of
mined ore at the limits of the mining for the Sellars and Greenberg Lenses,
but because of geo-referencing errors, a locational accuracy of only ± 5-10m
is estimated making these only suited to be reported to Inferred Resources.
Carne (1908) noted that this sampling on the footwall and endwall faces was
the accepted method to test for possible further extensions to mining, in the
absence of exploration drilling. Sample widths were the full horizontal width
of mineralisation at that location, ranging from 0.39-5.2m.
Short search radii in the Y direction have been used in an attempt to limit
extrapolation and smearing of these high-grade copper values (mostly between
1-12% Cu) across the mineralised lodes where channel samples have not covered
any lower grade regions.
CRITERIA USED FOR CLASSIFICATION
Resources were classified in accordance with the Australasian Code for the
Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC
Code, 2012 Edition).
The classification of Mineral Resources was completed by ROM Resources based
on geological confidence, drill hole spacing, data density and grade
continuity. The Competent Person is satisfied that the result appropriately
reflects his view of the deposit.
Continuous zones meeting the following criteria were used to define the
resource class:
Measured Resource
Measured Mineral Resources consist of the high confidence material which has
been grade control drilled (10x15m) with a high proportion of diamond-cored
holes. However, no material is categorised as Measured in this resource
estimation.
Indicated Resource
Indicated Mineral Resources reflects moderate confidence material with good
data density. It reflects a nominal drill spacing of less than 25m x 25m
resource definition drilling, through to grade control drilling (10 x 15m
spacing). No insitu material was classified as Indicated but small tonnages
have been ascribed to the Smelter slag and McDonough's stockpiles, both of
which have drone survey, extensive channel sampling, and favourable
metallurgical testing.
Inferred Resource
The Inferred Mineral Resource reflects the ongoing uncertainty in the location
of mined adits, stopes, and shafts (possibly errors of ± 5 - 10m), with the
amount of undocumented mining unknown at this stage. There is reasonable
continuity of the massive sulphides between each modelled lens, and
mineralisation outside mined strata, as confirmed by drill intersection with
mostly RC drilling.
SAMPLE ANALYSIS METHOD
All the analyses bar a few (<75 out) samples were laboratory tested in
various NATA registered laboratories throughout Australia. Many of the earlier
CRA Exploration stream sediment and soil samples were analysed by CRA internal
laboratories.
Portable XRF
XRF geochemical data taken from field portable XRF Olympus.
Duration of sampling 30 seconds per filter (3 filters).
Calibration of the unit was carried out on the unit at the start of the
sampling at the core library.
The following elements were analysed; Ag, As, Se, Ca, K, S, Ba, Sb, Sn, Cd,
Pd, Zr, Sr, Rb, Pb, Hg, Zn, W, Cu, Ni, Co, V, Ti, Au, Fe, Mn, Cr, Sc, Mo, Th,
U, Ta.
Over 220 surface samples have had their assays duplicated.
Laboratory testing
Laboratory testing consisted of a multi-suite analysis methodology (ME-MS61)
which involves a four-acid digestion, were completed by ALS in Orange and/ or
Brisbane QLD, for the following elements ; Ag, As, Se, Ca, K, S, Ba, Sb, Sn,
Cd, Pd, Zr, Sr, Rb, Pb, Hg, Zn, W, Cu, Ni, Co, V, Ti, Au, Ga, Ge, LI, La, Fe,
Mn, Cr, Sc, Mo, Th, U, Ta.
Samples containing >10,000ppm Cu are being tested by method CU-OG62 (Four
acid digestion and ICP finish, 0.4g sample). Any samples containing
>10,000ppm Zn were treated in a similar manner.
Gold was tested by Fire Assay methods at ALS using method Au-AA25.
None of the historical data has been adjusted.
ESTIMATION METHODOLOGY
For grade estimation and interpolation into the block model inverse distance
to a power of 2 with the polygonal method was used as a check estimate. At
this stage of the evaluation of the resource, enough data has been collected
to undertake a preliminary 3D geostatistical study, but for this update the
ID2 method is still deemed acceptable.
To inhibit bleed of the higher-grade ore below the oxidation boundary a
transition surface was created, and the blocks coded differently above and
below this surface as "OXID" or "FRESH", with different search ellipses being
employed for each domain.
It was noted that unsampled intervals were present within the mineralisation
domains. These intervals represent internal waste zones, which were too narrow
and not able to be wireframed separately. It should be noted, that given the
current drill spacing, these may smear the overall interpolation to blocks.
This may be attributed, in part, to data spacing, and may not be a true
reflection of grade continuity. No assumptions have been made regarding
by-products, although the copper mineralised zones contain considerable
secondary mineralisation, being Au, Ag, Co, and Zn.
A single block model for Cangai Copper Mine was constructed using a 10 mE by
10 mN by 4 mRL parent block size with sub-celling to 5 mE by 5 mN by 2 mRL for
domain volume resolution. This block size is adequate for the mineralisation
style. The size of the search ellipse for inverse distance was set to X= 90m
Y=35m Z =24m rotated 126 degrees in X, 0 degrees in Y and 85 degrees in Z.
Octants were established with a minimum of 3 octants to be filled for a valid
estimate.
CUT-OFF GRADE AND BASIS FOR SELECTED CUT-OFF GRADE
The resource model is constrained by assumptions about potential economic
cut-off grades. The Mineral Resource wireframes were generated using a 0.1% Cu
wireframe threshold and reported using a reporting cut-off grade of 0.2% Cu.
MINING/METALLURGICAL METHODS, PARAMETERS AND OTHER MATERIAL MODIFYING FACTORS
Since the 2017 maiden MRE, some metallurgical testing has taken place. Two
composites formed from bulk samples taken in April 2018 from McDonough's
Portal and Shaft stockpiles along the line of lode(7) have been the focal
point of metallurgical test-work. The test-work in the laboratory has
demonstrated the ore has beneficiated materially. Furthermore, results to
date have confirmed solid copper concentrate recoveries that exceeded 80%,
while the grade was up to 22% Cu and Co 300ppm(7).
In September 2019 assay results for samples collected from legacy stockpiles
at Smelter Creek Slag stockpile and another composite along the line of lode
(Marks and McDonough's dumps) were received back from the Peacocke &
Simpson Laboratory in Zimbabwe, with average head grades at 1.23% and 2.03% Cu
respectively(7).
Further work completed in December 2019, using a representative insitu massive
sulphide ore sample extracted from drillhole CC0023R completed in August 2018,
reported a commercial grade concentrate of 22.2% Cu & 7.4% Zn with a
recovery of 79.3% of total contained copper was achieved, which is in line
with previous investigations(7). The following observations were made:
· This result was derived from using standard metallurgical flotation
methods.
· The result is highly encouraging as it provides first-hand insight on
a potential final copper concentrate product from using high-grade CCM ore,
and
· The composite sample utilised in the metallurgical test-work process
comprised high-grade massive sulphide RC chips with a head grade of 8.18% Cu
and 4.36% Zn(7).
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
Gracechurch Group (Financial PR) +44 (0)20 4582 3500
Harry Chathli, Alexis Gore, Henry Gamble
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 the report to which this statement is attached that relates
to Exploration Targets, Exploration Results, Mineral Resources or Ore Reserves
is based on information compiled by Mark Biggs, who is a Member of The
Australasian Institute of Mining and Metallurgy (see Table below). Mr Mark
Biggs is the Managing Director of ROM Resources and has sufficient experience
that is relevant to the style of mineralisation and type of deposit 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'. These
Resource Estimations have been carried out in accordance with the principles
and guidelines of the Australian Code for Reporting of Mineral Resources and
Mineral Reserves published in December 2012 (JORC Code) and are reported as of
the 30th of June 2023. It should be noted that where Exploration Target
tonnages are calculated in the report, they are considered conceptual in
nature. There has been insufficient exploration to define a Mineral Resource
and that it is uncertain if further exploration will result in the
determination of a Mineral Resource.
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.
References
1) CCZ ASX Release - 6 September 2017
2) CCZ ASX Release - 24 September 2018
3) Carne, J.E., 1908, The Copper Mining Industry and the Distribution
of Copper Ores in New South Wales, 2nd Edition, New South Wales Department of
Mines, Geological Survey, Mineral Resources No. 6, 1908, pp. 180-186.
4) McQueen, K., 2019, Cangai copper: History of 'a good little
earner', Journal of Australasian Mining History, Vol. 17. October 2019, 96,
24pp
5) Honours thesis by Carl Brauhart UNSW (1991) "The Geology &
Mineralisation of the Cangai Copper Mine, Coffs Harbour Block Northeastern New
South Wales," CRAE Report No: 17739
6) Geological Survey of New South Wales Minview Portal. Available at:
https://minview.geoscience.nsw.gov.au/#/?lon=148.5&lat=-32.5&z=7&l=
(https://minview.geoscience.nsw.gov.au/#/?lon=148.5&lat=-32.5&z=7&l=)
7) References relating to MRE:
a. Biggs M.S. and Nowland M.L., 2017, EL 8562 and 8635 Jackadgery
North Project, Geological Overview Report, prepared by ROM Resources for Total
Minerals Pty Ltd, unpublished, July 17, 13pp.
b. Biggs, M.S., and Miniailo, K., 2017, EL 8625 & EL 8635
Jackaderry South, Resource Model Report, Cangai Mine Project, Grafton NSW,
prepared by ROM Resources for Castillo Copper Limited, unpublished, Sep 17,
48pp.
c. Brauhart, C., 1991, "The Geology & Mineralisation of the Cangai
Copper Mine, Coffs Harbour Block Northeastern New South Wales," University of
New South Wales Honours Thesis and CRAE Report No: 17739
d. Castillo Copper Limited, 2018a, ASX Release - Stockpile tests
produce high recoveries and grades up to 22% Copper, 2(nd) August 2018, 25pp.
e. Castillo Copper Limited, 2018b, ASX Release - Cangai update:
Down-hole electromagnetic surveys completed at Volkhardt's Lode, 24(th)
September 2018, 26pp.
f. Nowland, M. L. (2022). EL 8625 Cangai Mine Project Annual Report
for 12-month period ending 17 July 2022. Prepared by ROM Resources for
Castillo Copper Limited.
g. Wikipedia, 2023, Cangai Copper Mine, accessed 5/7/2023,
https://en.wikipedia.org/wiki/Cangai_Copper_Mine
(https://en.wikipedia.org/wiki/Cangai_Copper_Mine)
APPENDIX A: CANGAI COPPER MINE DRILL-HOLE DATA
FIGURE A1: DRILLHOLES USED IN THE MODEL
Hole MGA56 MGA56 AHD Depth INC Grid Source Type
Easting Northing Azimuth
CC0019R 450913.69 6736268.50 329.30 37.00 -55 56.6 CCZ RC
CC0020R 450918.72 6736266.50 327.20 149.87 -60 93.6 CCZ RC
CC0021R 450910.63 6736272.00 331.50 106.00 -50 356.6 CCZ RC
CC0022R 450910.59 6736271.00 331.05 144.97 -65 356.6 CCZ RC
CC0023R 450912.03 6736270.50 330.57 121.09 -64 26.6 CCZ RC
CC0024R 450912.41 6736271.50 331.10 84.07 -51 28.6 CCZ RC
CC0025R 450914.28 6736269.50 329.70 115.00 -65 51.6 CCZ RC
CC0026R 450914.78 6736270.00 329.90 102.08 -53 48.6 CCZ RC
CC0027R 450912.16 6736270.00 330.30 145.19 -81 26.6 CCZ RC
CC0028R 450907.19 6736271.50 331.50 150.10 -59 328.6 CCZ RC
CC0029R 450582.31 6736501.50 265.30 84.04 -55 74.6 CCZ RC
CC0030R 450583.19 6736499.50 266.60 103.02 -75 87.6 CCZ RC
CC0031R 450582.41 6736498.00 267.60 127.01 -75 111.6 CCZ RC
CC0032R 450583.31 6736498.00 267.60 118.02 -55 111.6 CCZ RC
CC0033R 450581.69 6736500.00 266.30 147.02 -85 81.6 CCZ RC
CC0034R 450540.59 6736546.50 242.00 79.06 -85 26.6 CCZ RC
CC0035D 450909.00 6736270.00 330.60 116.22 -77 23.6 CCZ DDH
CC0036D 450911.59 6736269.00 329.80 62.00 -62 17.6 CCZ DDH
CRC001 450791.84 6736331.00 358.10 174.07 -45 53.6 CCZ RC
CRC002 450792.25 6736329.00 358.00 57.93 -50 66.6 CCZ RC
CRC003 450791.09 6736328.50 358.00 71.18 -60 66.6 CCZ RC
CRC004 450776.63 6736324.00 357.00 132.16 -60 67.1 CCZ RC
CRC005 450775.75 6736324.00 356.90 252.30 -60 93.1 CCZ RC
CRC006 450776.31 6736328.50 356.50 120.11 -50 9.6 CCZ RC
CRC007 450765.75 6736322.50 356.20 111.14 -65 63.6 CCZ RC
CRC008 450765.16 6736322.00 356.20 240.08 -70 67.6 CCZ RC
CRC009 450751.31 6736318.00 355.20 174.16 -55 22.6 CCZ RC
CRC010 450751.84 6736317.00 355.30 228.18 -70 29.6 CCZ RC
CRC011 450670.28 6736464.00 283.60 201.15 -90 359.6 CCZ RC
CRC012 450665.28 6736467.50 281.40 198.26 -55 270.0 CCZ RC
CRC013 450668.50 6736471.50 280.50 250.12 -55 315.1 CCZ RC
CRC014 450677.91 6736466.00 285.10 262.37 -55 127.1 CCZ RC
CRC015 450464.84 6736639.50 202.89 198.13 -55 149.6 CCZ RC
CRC016 450463.28 6736649.00 198.10 198.11 -55 164.6 CCZ RC
CRC017 450460.09 6736650.00 199.10 198.21 -55 226.6 CCZ RC
CRC018 450457.13 6736655.50 198.50 198.07 -55 263.6 CCZ RC
BJAC1 450002.90 6736007.80 317.00 226.70 -60 226.7 WMC DDH
BJAC2 449672.90 6735545.80 318.90 193.50 -60 21.7 WMC DDH
DD91CG1 450687.10 6736294.70 362.00 15.00 -70 46.7 CRAE DDH
DD91CG2 450686.12 6736294.71 362.00 421.10 -70 46.7 CRAE DDH
DD91CG3 450432.50 6736371.71 316.00 402.40 -28 42.7 CRAE DDH
DD91CG4 450644.90 6736943.80 278.00 180.00 -45 53.7 CRAE DDH
DD91CG5 451171.57 6736064.02 226.00 275.00 -45 13.7 CRAE DDH
DDH2 450557.93 6736414.93 330.00 228.60 -70 37.7 UNION DDH
DDH5 451080.00 6736155.00 268.00 132.70 -60 26.7 UNION DDH
Source: CCZ geology team
FIGURE A2: 2017-2018 DRILLHOLES - BEST INTERSECTIONS
From (m) To (m) App Thick. True Thick. Cu % Zn % Ag g/t
CRC001 40 45 5 3.1 0.17 0.06 0.52
CRC002 Mining void
CRC003 67 68 1 0.62 1.56 0.26 3.71
CRC004 92 97 5 3.1 2.25 0.61 6.52
99 100 1 0.62 0.44 0.11 2.19
CRC005 221 225 4 2.48 1.54 1.17 11.49
CRC006 69 71 2 1.24 0.81 0.67 4.88
72 73 1 0.62 0.47 0.14 3.15
CRC007 Mining void
CRC008 210 213 3 1.86 0.42 0.15 2.81
216 217 1 0.62 0.56 0.21 3.84
228 232 4 2.48 0.88 0.27 5.4
CRC009 100 102 2 1.24 0.73 0.16 3.26
CRC010 145 147 2 1.24 0.63 0.18 13.14
CRC011 8 9 1 0.62 0.21 0.06 2.26
CRC012 9 11 2 1.24 0.34 0.08 6.17
CRC013 1 7 6 3.72 2.69 0.39 9.22
CRC014 232 233 1 0.62 0.75 0.13 1.93
CRC016 0 1 1 0.62 1.14 0.18 7.9
CRC017 4 7 3 1.86 0.71 0.11 2.22
CRC018 0 1 1 0.62 0.69 0.11 1.93
7 8 1 0.62 0.55 0.21 1.85
13 14 1 0.62 1.43 0.17 2.32
34 35 1 0.62 0.68 0.22 1.94
39 41 2 1.24 2.17 0.71 3.73
CC0020R 14 15 1 0.62 0.39 0.04 0.11
CC0021R 51 52 1 0.62 0.91 0.21 8.74
CC0022R 92 94 2 1.24 2.56 0.38 9.78
98 99 1 0.62 0.81 0.54 5.55
109 114 5 3.1 1.53 0.37 6.9
CC0023R 40 53 13 8.06 4.72 2.04 17.15
56 58 2 1.24 2.27 2.78 10.88
72 74 2 1.24 0.53 0.1 1.32
77 78 1 0.62 0.41 0.07 1.81
85 87 2 1.24 1.19 0.35 11.22
CC0024R Mining void
CC0025R 90 93 3 1.86 2.66 0.5 7.38
103 106 3 1.86 1.26 0.37 6.36
CC0026R 53 54 1 0.62 0.46 0.17 1.54
CC0026R 57 60 3 1.86 0.63 0.19 3.44
CC0027R 125 126 1 0.62 0.55 0.39 2.57
CC0028R 109 110 1 0.62 0.54 0.13 3.05
119 120 1 0.62 0.28 0.06 2.22
CC0029R 36 38 2 1.24 2.66 0.78 10.33
CC0030R 56 59 3 1.86 2.74 0.63 10.33
CC0031R 70 73 3 1.86 0.5 0.11 1.91
CC0032R 56 62 6 3.9 0.63 0.18 1.47
CC0033R 74 75 1 0.6 0.21 0.06 1.06
CC0034R 41 42 1 0.62 0.98 0.26 5.55
CC0035D 9 14 5 3.1 0.26 0.05 0.25
CC0036D 10 14 4 2.48 0.23 0.03 0.05
49.2 55.1 5.9 3.66 3.79 1.9 15
APPENDIX B: GEOLOGICAL MODEL REPORT
At Cangai Copper Mine structurally controlled epigenetic copper mineralisation
is found in multiple breccia zones in an otherwise monotonous dacitic tuff,
associated with felsic dykes. There are hints from FLEM interpreted anomalies
of similar, en-echelon structures nearby, one of these being the Smelter Creek
Copper Prospect. At Cangai Copper Mine, a high-grade supergene zone is
dominated by malachite and azurite. Below the base of complete oxidization,
fresh mineralised rock dominated by chalcopyrite, bornite, and minor
sphalerite.
Workings have been resurveyed and georeferenced to MGA94 Z56, shifting the
previously estimated (early 2017) locations of mine plans 40m to 60m to the
north and north-east. The 2017 to 18 Stage and 2 drilling programmes were
hampered by very steep topography, changes in site staff, tight environmental
conditions for access and pads, and the fact that seven holes hit workings
which either terminated the holes abruptly or caused sample loss in deeper
sections if the drilling continued.
The current block model was updated with the 2017-2018 drilling, surface
channel sampling, and historical mine channel sampling (only assayed for Cu).
The drilling and ground mapping programme has allowed geo-referencing of the
mine workings to be completed. Some of the original 2017 wireframes were too
wide and have been discarded. Surface FLEM, DHEM, and soil surveys identified
several anomalies on and off the main line of lode and these are subject to
current field planning.
Since December 2017 Castillo has completed:
· Drone topographic survey.
· Re-survey collars of historical holes.
· 34 new RC holes and 2 HQ diamond cored holes, with detailed assay and
XRF and DHEM survey on selected holes. Further, the cored holes have magnetic
susceptibility readings taken.
· FLEM ground survey completed.
· Channel sampling and survey of mine reject dumps and smelter slag
reject dump.
· Geo-referencing of underground channel sampling at Sellars and
Greenberg's lenses undertaken by the Grafton Copper Mining Company in the
early nineteen hundreds.
· More geological mapping carried out.
· Accurate survey on mine portals, adits, and opencast pit locations.
The biggest shortfall on the two-stage drilling programme was that once the
drilling hit significant workings the hole was lost due to a loss of
circulation, so no samples from the actual mined/mining oxidized zone were
available to confirm the higher grades that should remain.
Modelling notes are summarised as follows:
· Topography was from a drone survey with accuracies about ± 0.05m on
the Australian map grid 1994 -Zone 56.
· Drillhole samples were loaded, validated, and then processed using a
fixed length compositing tool in Datamine to 1m.
· A preliminary geostatistical study was completed using the Lidenbrock
software. Short ranges (<50m) for copper were noted.
· Datamine Block model software was used to generate 10m x 10m x 4m
blocks, sub-celled to half that size, where data criteria were met.
· Inverse Distance squared and ordinary kriging interpolation
algorithms were used.
· The database contains all surface drillhole samples analysed using
ALS Methods ME-MS61, MS-ME61R, and AAU25, AAU26. The database also contains
assays for all ex-mine dumps, and current and historical surface sampling.
· Assay parameters modelled included a subset of Ag, As, Au, Co, Cu,
Fe, In, Mn, Pb, S, Zn and RDI (insitu relative density).
Drift plots show the distribution of the copper by easting and northing in
Figures B1 and B2, below.
FIGURE B1: COPPER DRIFT PLOT BY EASTING
Source: CCZ geology team
FIGURE B2: COPPER DRIFT PLOT BY NORTHING
Source: CCZ geology team
All relevant diagrams and tables for the full complements of assays results
(Figures B3 to B4) follow.
FIGURE B3: DRILL-HOLES COMPLETED ALONG THE LINE OF LODE
Source: CCZ geology team
FIGURE B4: CROSS SECTIONS FOR DRILL-HOLES CC0021-24R (Cu and Au).
Source: CCZ geology team
APPENDIX C: EX-MINE AND STOCKPILE RESOURCE INVENTORY
FIGURE C1: CANGAI COPPER MINE - LOCATION OF MAJOR STOCKPILES
Notes:
1. Only Lenses 7 & 8 currently have wireframes and metallurgical
testing (Figure C-1).
2. A five (5) hole drilling programme is planned for the Smelter Creek
Slag dump, in Q4 2023.
Source: CCZ geology team
FIGURE C2: STOCKPILE RESOURCE INVENTORY
IDX Dump_Name Classification Type Wireframe Drone Survey Channel Samples Metallurgy Typical Sample ID's Area Average Thickness Volume Density (@10% void) Mass (t) Indicated Mass (t) Inferred Ag (g/t) Au (g/t) Co (ppm) Cu (%) In (ppm) Zn (%) Contained Cu @100% Comments
1 Melbourne_DDS_Dump Inferred Ex-Mine NO YES NO NO O5; 1012538 200 2 400 2.75 0 1,100 55 0.2 183 2.39 13 0.29 26 More work required
2 Melbourne_Dump_Y Inferred Ex-Mine NO YES NO NO 1012532 100 3 300 2.75 0 825 3.1 0.05 75 2.04 2 0.23 17 More work required
3 BO_Dump_X Inferred Ex-Mine NO YES NO NO 1012539 300 3 900 2.75 0 2,475 10.9 0.01 18 2.64 3 0.47 65 More work required
4 Greenberg Inferred Ex-Mine NO YES NO NO O8 500 3 1500 2.75 0 4,125 49 2.3 330 1.98 nd 0.95 82 More work required
5 Volkhaardt's Inferred Ex-Mine NO YES YES NO 1012528; O3 400 5 2000 2.75 0 5,500 6.8 0.8 31 1.89 3 0.08 104 More work required
6 Mark's Inferred Ex-Mine NO YES YES NO G1 1,700 3 5100 2.75 0 14,025 6 0.18 190 2.15 nd 0.18 302 Potentially 30-50% destroyed during Environmental amelioration
7 A Level Hopper & McDonough's Indicated Ex-Mine YES YES YES YES 1012501; P&S2 1,900 4 7,600 2.75 20,900 1,000 7.1 0.27 61 2.03 2 0.17 445 Potentially 20-30% destroyed during Environmental amelioration
8 Smelter Ck Slag Dump Indicated Ex-Smelter YES YES YES YES P&S1 7,600 7 53,200 3.35 178,220 0 4.3 0.08 240 1.23 7 2.1 2,192 More work required
199,120 29,050 3,232
Inferred 14.5 0.58 157 2.1 1.4 0.3
Indicated 4.6 0.10 221 1.3 6.5 1.9
Source: CCZ geology team
APPENDIX D: JORC CODE, 2012 EDITION - TABLE 1; CANGAI DRILLING PROGRAMME
SECTION 1 SAMPLING TECHNIQUES & 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, or Samples from the 2017-2018 Cangai drilling programme were collected using the
specific specialised industry standard measurement tools appropriate to the reverse circulation method of drilling on a 1 metre basis. Initially 20-25kg
minerals under investigation, such as down hole gamma sondes, or handheld XRF of chips and dust was collected and riffled down to a 2-3kg sample for further
instruments, etc.). These examples should not be taken as limiting the broad lab analysis.
meaning of sampling.
• Include reference to measures taken to ensure sample representivity
and the appropriate calibration of any measurement tools or systems used. Field samples were firstly analysed with a Niton portable XRF device to
determine compositing rules.
• 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 Subsequently, sample advice forms were coded with all samples were delivered,
simple (e.g., 'reverse circulation drilling was used to obtain 1 m samples initially to ALS Orange laboratory and in Stage 2 to ALS Laboratory in
from which 3 kg was pulverised to produce a 30-g charge for fire assay'). In Brisbane QLD where the lab undertook the splitting and compositing of the 5m
other cases, more explanation may be required, such as where there is coarse composite samples and completed multi-element analysis on the 5m composite and
gold that has inherent sampling problems. Unusual commodities or 1m selected samples.
mineralisation types (e.g., submarine nodules) may warrant disclosure of
detailed information.
Drilling techniques • Drill type (e.g., core, reverse circulation, open hole hammer, rotary air Drilling was provided by Budd Drilling using a modified track mounted UDH RC
blast, auger, Bangka, sonic, etc.) and details (e.g. core diameter, triple or rig as illustrated below by Figure D1-1. Both reverse circulation and diamond
standard tube, depth of diamond tails, face sampling bit or other type, coring techniques were employed during the drilling programme.
whether core is oriented and if so, by what method, etc.).
FIGURE D1-1 BUDD DRILLING AT CANGAI
Drill sample recovery Method of recording and assessing core and chip sample recoveries and results Sample recovery was generally 90-100% for each metre except when mining
assessed. cavities (workings >1m wide) were intersected. Intersecting these
mining voids generally stopped drilling due to a loss of circulation and
Measures taken to maximise sample recovery and ensure representative nature of uncontrolled hole deviation.
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 geotechnically logged All drilling has been completed to high modern-day standard by a competent
to a level of detail to support appropriate Mineral Resource estimation, field teams & drill crew.
mining studies and metallurgical studies.
Whether logging is qualitative or quantitative in nature. Core (or
costean, channel, etc.) photography. Logging of the lithology has been to coded sheets for data entry into Excel
and added to the geological database. Plastic chip trays were used to store
•The total length and percentage of the relevant sample on 1m intervals for future reference as illustrated below in Figure
D1-2.
intersections logged
FIGURE D1-2 1M SAMPLE CHIPS PRESERVED IN PLASTIC SAMPLE TRAYS
Budd Drilling provided an Eastman single shot tool for determining hole
deviation. Readings were taken every 30m downhole. Hole deviations are
in-line with expectations and follow the trend of the geological features.
It should be noted that drillhole CRC013 was planned as a vertical hole but
deviated to the southwest.
Subsampling techniques and sample preparation If core, whether cut or sawn and whether quarter, half or all core taken. RC samples are collected in 1m samples and riffle split into calico bags at
the rig. The samples are weighed details recorded. A pXRF unit is utilized
If non-core, whether riffled, tube sampled, rotary split, etc. and whether to test the samples for mineralisation to determine which samples are tested
sampled wet or dry. For all sample types, the nature, quality, and as individual metres and which samples are to be composited into 5m samples.
appropriateness of the sample preparation technique. Quality control Composite samples were homogenized, and riffle split at the labs prior to
procedures adopted for all sub-sampling stages to maximise representivity of assaying.
samples.
Measures taken to ensure that the sampling is representative of the in-situ
material collected, including for instance results for field Industry acceptable standards and blanks were used as certified reference
material to ensure satisfactory performance of the laboratory. Duplicates
duplicate/second-half sampling. Whether sample sizes are appropriate to the were inserted in at a ratio of 1:20 of normal sampling.
grain size of the material being sampled.
HQ Cored holes were sawed in half with one half retained, and the other being
submitted for assay. Hole CC0035D was not previously analysed, with laboratory
assay revealing some high copper intervals.
Quality of assay data and laboratory tests The nature, quality and appropriateness of the assaying and laboratory Multi-suite analysis methodology (ME-MS61) which involves a four-acid
procedures used and whether the technique is considered partial or total. digestion, is being completed by ALS in Orange and Brisbane QLD, for the
following elements ; Ag, As, Se, Ca, K, S, Ba, Sb, Sn, Cd, Pd, Zr, Sr, Rb, Pb,
For geophysical tools, spectrometers, handheld XRF instruments, etc, the Hg, Zn, W, Cu, Ni, Co, V, Ti, Au, Ga, Ge, LI, La, Fe, Mn, Cr, Sc, Mo, Th, U,
parameters used in determining the analysis including instrument make and Ta.
model, reading times, calibrations factors applied and their derivation, etc.
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. Samples containing >1000ppm Cu are being tested for Au by fire assay method
CU-OG62. Gold was tested by Fire Assay methods at ALS (Au-AA25).
Verification of sampling and assaying The verification of significant intersections by either independent or All significant intercepts have been verified by two people, one ROM and one
alternative company personnel. from FieldCrew. Additionally, field reading of multi-elements were estimated
using a Niton and in Stage 2 an Olympus Vanta M Portable XRF analyser as
The use of twinned holes. conducted as in internal check prior to sending samples for laboratory
analysis. Reading times using 2 beam "Geochem Mode" was employed via
Documentation of primary data, data entry procedures, data verification, data 30sec/beam for a total of 60 sec.
storage (physical and electronic) protocols.
All logging and sampling data is collected, and data entered onto Excel
Discuss any adjustment to assay data. spreadsheets. These sheets were loaded into a Datamine GDB Database and
further validation steps were taken.
The responsible field geologist makes the modelling geologist aware of any
errors and/or omissions to the database and the corrections (if required) are
corrected in the database immediately.
No adjustments or calibrations are made to any of the assay data recorded in
the database.
No holes were deliberately twinned; however, two cored holes (CC0035D and
CC0036D) were drilled about the site of the CC0023R, which was treated as the
pilot hole.
Comparison of duplicate analyses did not reveal any major variances (most
element values <10% variance).
Location of data points Accuracy and quality of surveys used to locate drill holes (collar and Drill pads were initial located using an RTK differential GPS. Drillholes
down-hole surveys), trenches, mine workings and other locations used in collar locations have been picked using a Garmin handheld GPS to +4m. At
Mineral Resource estimation. completion, all drillholes were accurately surveyed. Collars RLs were
corrected and tagged to a recently completed Drone DTM topography model which
Specification of the grid system used. has accuracies for AHD of ±0.2m.
Quality and adequacy of topographic control.
Data spacing and distribution • Data spacing for reporting of Exploration Results. Drillholes CC0019R was abandoned after 36m due to Rig problems. Drillhole
CC0020R deviated too much from the original plan and was abandoned at 155m.
• 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. All other drillholes in the Stage 1 & 2 programme (Figure D1-3) were
drilled at a nominal pad-to-pad spacing of 180m. Drilling then proceeded on
• Whether sample compositing has been applied. each of the four (4) pads in a 180-degree fan fashion on 4 nominal
sections. It should be noted that this methodology was necessary due to
very steep topography and ESF4 conditions.
Whether the original samples were 1m or 5m in length, in the Datamine Block
model module the samples have been converted to a fixed length of 1m.
FIGURE D1-3: 2017-2018 DRILLHOLE PROGRAMME COLLAR LOCATIONS
Orientation of data in relation to geological structure Whether the orientation of sampling achieves unbiased sampling of possible The drilling was originally planned to intersect workings and drill into data
structures and the extent to which this is known, considering the deposit gaps between orebodies such that in general the intersections are where
type. possible (due to restricted access) perpendicular to a strike of 126 degrees
(see Table D1-1).
If the relationship between the drilling orientation and the orientation of
key mineralised structures is considered to have introduced a sampling bias, Additional surface bedding and foliation data, and that from some of the
this should be assessed and reported if material. accessible underground mine adits was compiled from a UNSW Honours thesis
(Brauhart 1991). Information is available from underground workings, open
cut(s), shaft(s), adit(s), shallow pits, and scrapings. The Lode is
sub-vertical to vertical, striking 126 degrees true north and pitching at 60
degrees to the west. The high-grade ore as mined, varies from 0.3m-8m wide,
true width.
The known copper-gold mineralisation around Cangai strikes from 290-330
degrees, It should be noted that these orebody shapes were drawn at >13% Cu
so that the with the major orebody shapes shown by Figure D1-4, below:
FIGURE D1-4: ORIENTATION OF COPPER-GOLD MINERALISATION AT THE CANGAI MINE
modelled wireframes in this current resource have been enlarged to try to
capture mineralisation down to 0.1% Cu.
Sample security • The measures taken to ensure sample security. Samples were bagged and sample advice for each hole was coded. Split samples
were delivered by Gnomic Exploration personnel to ALS Laboratories in Orange
(Stage 1) or by Mick Bavea to ALS Brisbane (Stage 2).
Audits or reviews • The results of any audits or reviews of sampling techniques and data. No audits or reviews have yet been undertaken of sampling techniques and data.
A review of the modelling process was received.
TABLE D1-1: CANGAI COPPER DRILLING COLLAR TABLE STAGE 1 & 2
Hole MGA56 MGA56 AHD Depth INC Grid Source Type
Easting Northing Azimuth
CC0019R 450913.69 6736268.50 329.30 37.00 -55 56.6 CCZ RC
CC0020R 450918.72 6736266.50 327.20 149.87 -60 93.6 CCZ RC
CC0021R 450910.63 6736272.00 331.50 106.00 -50 356.6 CCZ RC
CC0022R 450910.59 6736271.00 331.05 144.97 -65 356.6 CCZ RC
CC0023R 450912.03 6736270.50 330.57 121.09 -64 26.6 CCZ RC
CC0024R 450912.41 6736271.50 331.10 84.07 -51 28.6 CCZ RC
CC0025R 450914.28 6736269.50 329.70 115.00 -65 51.6 CCZ RC
CC0026R 450914.78 6736270.00 329.90 102.08 -53 48.6 CCZ RC
CC0027R 450912.16 6736270.00 330.30 145.19 -81 26.6 CCZ RC
CC0028R 450907.19 6736271.50 331.50 150.10 -59 328.6 CCZ RC
CC0029R 450582.31 6736501.50 265.30 84.04 -55 74.6 CCZ RC
CC0030R 450583.19 6736499.50 266.60 103.02 -75 87.6 CCZ RC
CC0031R 450582.41 6736498.00 267.60 127.01 -75 111.6 CCZ RC
CC0032R 450583.31 6736498.00 267.60 118.02 -55 111.6 CCZ RC
CC0033R 450581.69 6736500.00 266.30 147.02 -85 81.6 CCZ RC
CC0034R 450540.59 6736546.50 242.00 79.06 -85 26.6 CCZ RC
CC0035D 450909.00 6736270.00 330.60 116.22 -77 23.6 CCZ DDH
CC0036D 450911.59 6736269.00 329.80 62.00 -62 17.6 CCZ DDH
CRC001 450791.84 6736331.00 358.10 174.07 -45 53.6 CCZ RC
CRC002 450792.25 6736329.00 358.00 57.93 -50 66.6 CCZ RC
CRC003 450791.09 6736328.50 358.00 71.18 -60 66.6 CCZ RC
CRC004 450776.63 6736324.00 357.00 132.16 -60 67.1 CCZ RC
CRC005 450775.75 6736324.00 356.90 252.30 -60 93.1 CCZ RC
CRC006 450776.31 6736328.50 356.50 120.11 -50 9.6 CCZ RC
CRC007 450765.75 6736322.50 356.20 111.14 -65 63.6 CCZ RC
CRC008 450765.16 6736322.00 356.20 240.08 -70 67.6 CCZ RC
CRC009 450751.31 6736318.00 355.20 174.16 -55 22.6 CCZ RC
CRC010 450751.84 6736317.00 355.30 228.18 -70 29.6 CCZ RC
CRC011 450670.28 6736464.00 283.60 201.15 -90 359.6 CCZ RC
CRC012 450665.28 6736467.50 281.40 198.26 -55 270.0 CCZ RC
CRC013 450668.50 6736471.50 280.50 250.12 -55 315.1 CCZ RC
CRC014 450677.91 6736466.00 285.10 262.37 -55 127.1 CCZ RC
CRC015 450464.84 6736639.50 202.89 198.13 -55 149.6 CCZ RC
CRC016 450463.28 6736649.00 198.10 198.11 -55 164.6 CCZ RC
CRC017 450460.09 6736650.00 199.10 198.21 -55 226.6 CCZ RC
CRC018 450457.13 6736655.50 198.50 198.07 -55 263.6 CCZ RC
BJAC1 450002.90 6736007.80 317.00 226.70 -60 226.7 WMC DDH
BJAC2 449672.90 6735545.80 318.90 193.50 -60 21.7 WMC DDH
DD91CG1 450687.10 6736294.70 362.00 15.00 -70 46.7 CRAE DDH
DD91CG2 450686.12 6736294.71 362.00 421.10 -70 46.7 CRAE DDH
DD91CG3 450432.50 6736371.71 316.00 402.40 -28 42.7 CRAE DDH
DD91CG4 450644.90 6736943.80 278.00 180.00 -45 53.7 CRAE DDH
DD91CG5 451171.57 6736064.02 226.00 275.00 -45 13.7 CRAE DDH
DDH2 450557.93 6736414.93 330.00 228.60 -70 37.7 UNION DDH
DDH5 451080.00 6736155.00 268.00 132.70 -60 26.7 UNION DDH
Source: CCZ geology team
SECTION 2: REPORTING OF EXPLORATION RESULTS
(CRITERIA LISTED IN THE PRECEDING SECTION APPLY TO THIS SECTION)
Criteria JORC Code explanation Commentary
Mineral tenement and land tenure status • Type, reference name/number, location and ownership including • Castillo Copper holds 100% of EL 8625 & EL 8635. The tenure has been
agreements or material issues with third parties such as joint ventures, granted for a period of thirty-six months until 17(th) July 2020, for Group 1
partnerships, overriding royalties, native title interests, historical sites, minerals. The location of the tenure is shown in Figure D2-1 below:
wilderness or national park and environmental settings.
FIGURE D2-1: LOCATION OF EL 8625 AND EL8635 JACKADERRY SOUTH
• 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 current drilling has all been completed on EL 8625 and EL 8635 Jackaderry
South only.
Exploration done by other parties • Acknowledgment and appraisal of exploration by other parties. Some mining history and discovery information provided by North Broken Hill
Ltd (1970) is as follows:
Previous explorers (Brownlow, 1989; Abraham-Jones, 2012) have noted that a
'basement window' of exposed magmatic hydrothermal alteration and historical
copper workings may represent the western and upper extent of a much larger
hydrothermal system concealed under Mesozoic cover to the east, prospective
for:
• Quartz-tourmaline-sulphide-cemented, magmatic-hydrothermal
breccia hosted copper-gold-molybdenum-cobalt (Cu-Au-Mo-Co) deposit.
• Concealed porphyry copper-gold-molybdenum-cobalt
(Cu-Au-Mo-Co) ore body associated with quartz diorite to tonalitic porphyry
apophyses proximal to the tourmaline-sulphide cemented breccia's.
• Potential also exists for copper-gold (Cu-Au) skarn.
Considerable exploration has taken place in and around the Cangai Copper Mine
(closed) by several large explorers such as Western Mining and CRA
Exploration, the results of which are covered in the Local Geology section
Geology Deposit type, geological setting and style of mineralisation. Regional Geology
The underlying geology is contained within the Coffs Harbour Block, east of
the Demon Fault. The major basement unit is the Silurian-Devonian Silverwood
Group (locally the Willowie Creek Beds), a mixed sequence of tuffaceous
mudstones, intermediate to basic igneous rocks, slates, and phyllites, a low
stage of regional metamorphism.
Overlying this rock formation is a younger tectonic melange of Early
Carboniferous age - the Gundahl Complex of slates, phyllites and schist, with
chert, greenstone, and massive lithic greywackes.
These rocks are intruded by the Early Permian Kaloe Granodiorite (tonalite),
which also in turn is intruded by numerous later-stage mafic (lamprophyre)
dykes.
Local Geology
The local geology is well understood as considerable exploration has taken
place in and around the Cangai Copper Mine (closed) by several major explorers
such as Western Mining and CRA Exploration, the results of which are covered
in the section below. The mineralisation is controlled by the presence of
shear zones within the country rock and persistent jointing. Chloritic
alteration is pervasive, with the major minerals identified (Henley and Barnes
1990) as:
• Azurite major ore
• Chalcocite major ore
• Chalcopyrite major ore
• Copper major ore
• Malachite major ore
• Pyrite major ore
• Pyrrhotite major ore
• Arsenopyrite minor ore
• Sphalerite minor ore
• Cuprite minor ore
• Gold minor ore
• Limonite minor ore
• Chlorite major gangue
• Calcite major gangue
• Quartz major gangue
• Sericite minor gangue
The structurally controlled epigenetic copper mineralisation is found in
multiple breccia zones in an otherwise monotonous dacitic tuff, associated
with felsic dykes. There are hints of similar, en-echelon structures
nearby. A high-grade supergene zone is dominated by malachite and azurite.
Below the base of complete oxidization, there is fresh mineralised rock
dominated by chalcopyrite (see Figure A2-2), bornite, and minor sphalerite.
After an extensive major surface mapping exercise, old mine workings have been
resurveyed and georeferenced to the MGA94 Z56 datum, shifting the previously
estimated (early 2017) locations of mine plans 40 to 60m to the north and
northeast.
FIGURE D2-2 COPPER MINERALISATION IN HQ DRILLHOLE CC0036D
Western Mining 1982-1984
Western Mining found that the recognition of substantial amounts of pyrrhotite
in high grade ore collected from mine dumps led to the reappraisal of previous
explorer's ground magnetics (Brown, 1984). Two soil anomalies were
identified @ +60ppm Cu (max 1100ppm) and several strong linear magnetic
anomalies (=250nT above background). Soil sampling and detailed ground
inspections conducted over the linear magnetic high failed to identify any
anomalous geochemistry or a possible source lithology. A 180m diamond drill
hole was drilled to test the anomaly. Given the poor results of both the
drilling and the follow-up stream sediment sampling, no further work was
recommended. The decision was made to relinquish the licence in 1984.
CRA Exploration 1991-1992
CRA Exploration examined the geological form, setting and genesis of the
mineralisation at the Cangai Copper Mine over several years. The work
carried out consisted of geological mapping, collection of rock chip samples,
and underground investigations at the mine site. Drill core from a CRA
exploration programme and mine dumps were also inspected. They concluded
that the Cangai Copper Mine is hosted by sedimentary rocks of the
Siluro-Devonian Willowie Creek Beds of tuffaceous mudstones, tuffaceous
sandstones, and conglomerates. Mineralisation appears to be associated with
steeply plunging ore shoots in and adjacent to the main shear zone (Figure
A2-2). Massive primary ore consists of chalcopyrite, pyrite and pyrrhotite
with lesser sphalerite and minor arsenopyrite and galena. A detailed, well
documented report was produced, but no reasons were given for the
relinquishment of the licence.
FIGURE A2.2: ROCK CHIP SAMPLING AT CANGAI COPPER MINE
Drill hole A summary of all information material to the understanding of the exploration All historical holes were used except BJAC1 and 2, which were drilled outside
results including a tabulation of the following information for all Material the block model boundaries. Drill hole collar summary and intersection summary
Information drill holes: tables are included as Appendix A in this report and progressively in various
Castillo Copper ASX release throughout 2018.
• easting and northing of the drill hole collar
Mineralised zones are identified by the field geologist and flagged as
• elevation or RL (Reduced Level - elevation above sea level in geological/mineralised zones as shown in Table D2-1 at the end of this
metres) of the drill hole collar section.
• dip and azimuth of the hole
• down hole length and interception depth
• 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, maximum No top cuts have been applied to reporting of the significant Intersections
and/or minimum grade truncations (e.g., cutting of high grades) and cut-off and lower cut of 0.2% (2,000ppm) Cu has generally been used. Full detailed
grades are usually Material and should be stated. Where aggregate intercepts assay intervals for the key elements are included in the Appendices of the
incorporate short lengths of high-grade results and longer lengths of Cangai CP report.
low-grade results, the procedure used for such aggregation should be stated
and some typical examples of such aggregations should be shown in detail.
The assumptions used for any reporting of metal equivalent values should be Summary Intersections per 2017 to 2018 drillhole have been reported based on
clearly stated. estimated laboratory assays in Appendix A of this release, with a minimum
criteria = 0.5% Cu or 0.2% Zn or 2 g/t Ag if assays. For visual sulphide
estimates ranges given the following criteria apply:
1. Disseminated sulphides > 5%-10% sulphides.
2. Semi-Massive 10% - 30% sulphides
3. Massive over 30% sulphides
There has been no reporting of metal equivalent values in this mineral
resource estimate.
Relationship between mineralisation widths and intercept lengths These relationships are particularly important in the reporting of Exploration All intersections are reported as downhole widths. Once assays are returned
Results. and the geological controls are fully established, the 3D modelling package
will determine true widths.
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 The Lode is currently modelled to be sub-vertical to vertical, striking 126
hole lengths are reported, there should be a clear statement to this effect degrees and pitching at 60 degrees west. Varies from 0.3m-5.2m wide. The main
(e.g. 'down hole length, true width not known'). mining was from Volkhardt's, Melbourne, Mark's, Sellar's, Volkhardt's and
Greenberg's lens. The secondary supergene zone grades averaged 20-35% Cu.
The sulphide zone decreased to 8-10% Cu at depth. The Lode was largest at
structural intersections. Breccia was recorded at D level.
The host rock is massive fine-grained intermediate volcanic, and bedding is
difficult to define. The deposit is structurally controlled with lodes
following or adjacent to the shear zone. A temperature of formation is
suggested to be about 380 degrees centigrade (Brauhart 1991). The NSW
Geological Survey has characterized Cangai as a meta-hydrothermal structurally
controlled deposit. Figure D2-3 below is a cross-section showing the four
(4) main near vertical mineralised zones at the Cangai Mine.
FIGURE D2-3: NW TO SE CROSS-SECTION OF WORKINGS AT CANGAI MINE
Geo-registering was undertaken in June 2018, particularly the anomalous zones
(which are in the process of being digitised off the 1908,1912, and 1914 mine
plans (Brauhart 1991), which become priority targets for geological mapping,
ground magnetic and EM surveys. Data has also been extracted from a thorough
UNSW Honours Thesis as referenced below: Brauhart, C. (1991). The Geology
& Mineralisation of the Cangai Copper Mine, Coffs Harbour Block
Northeastern New South Wales. CRAE Report No: 17739. University of NSW.
Diagrams Appropriate maps and sections (with scales) and tabulations of intercepts Appropriate diagrams have been included in the body text (Appendix B) of this
should be announcement and previous ASX announcements (see references).
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.
Balanced reporting Where comprehensive reporting of all Exploration Results is not practicable, All drillholes completed to date have been reported in various Castillo Copper
representative reporting of both low and high grades and/or widths should be ASX releases.
practiced avoiding misleading reporting of Exploration Results.
Other substantive exploration data Other exploration data, if meaningful and material, should be reported Historical explorers have also conducted airborne and ground gravity,
including (but not limited to): geological observations; geophysical magnetic, EM, and resistivity surveys over parts of the tenure area but this
survey results; geochemical is yet to be collated. A surface EM Survey has been undertaken and has been
previously reported (multiple conductors discovered from FLEM survey (Castillo
survey results; bulk samples - size and Copper 8(th) January 2018 ASX Release).
method of treatment; metallurgical test results; bulk density, groundwater, Castillo Copper also conducted DHEM surveys on eight (8) drillholes, two of
geotechnical and rock characteristics; potential deleterious or contaminating which produced EM anomalies modelled as plates by the Maxwell software
substances.
Future Work The nature and scale of planned further work (e.g., tests for lateral CCZ's geology team have mapped out the next drilling campaign that will
extensions or depth extensions or large-scale step-out drilling). specifically target extending the known copper orebody (Figure A2-4) through
the following actions, Targeting the following locations:
Diagrams clearly highlighting the areas of possible extensions, including the
main geological interpretations and future drilling areas, provided this
information is not commercially sensitive.
• Smelter Creek Copper Smelter Dumps
• Along strike and under the McDonough's workings
• Proximal to Marks' workings
• Underneath Volkhardt's' workings
• DHEM anomaly located along strike from CRC005.
FIGURE A2-4 POTENTIAL EXPLORATION DRILLING AREAS
TABLE D-1: GEOLOGICAL QUALITATIVE MINERALISATION DESCRIPTIONS
Hole ID From (m) To (m) Cu (ppm) Zn (ppm) Ag (g/t) Au (g/t) Sulphide mineral (%) Geology comments
CC0020R 14 15 3860 402 0.11 0.01 - -
CC0021R 51 52 9060 2070 8.74 0.11 < 5% pyrite and chalcopyrite -
CC0022R 92 93 40100 5750 15.45 0.12 10-15% chalcopyrite, 10-15% pyrite, 5-10% pyrrhotite Massive sulphide
CC0022R 93 94 6510 1370 2.86 0.02 < 5% pyrite and chalcopyrite Disseminated sulphides
CC0022R 98 99 8080 5380 5.55 0.05 < 5% pyrite and chalcopyrite Disseminated sulphides
CC0022R 109 110 6270 1600 5.52 0.12 < 5% pyrite and chalcopyrite Disseminated sulphides
CC0022R 109 110 5410 1380 5.20 0.10 < 5% pyrite and chalcopyrite Disseminated sulphides
CC0022R 110 111 14650 3280 9.01 0.22 5-10% pyrite and chalcopyrite, pyrrhotite Semi-massive sulphide
CC0022R 111 112 27800 6780 12.55 0.23 5-10% pyrite and chalcopyrite, pyrrhotite, < 5% sphalerite Semi-massive sulphide
CC0022R 112 113 23200 6310 6.60 0.19 5-10% pyrite and chalcopyrite, pyrrhotite, < 5% sphalerite Semi-massive sulphide
CC0022R 113 114 12350 2840 3.22 0.07 5-10% pyrite and chalcopyrite, pyrrhotite Semi-massive sulphide
CC0023R 40 41 7430 1720 2.29 0.06 < 5% pyrite and chalcopyrite Disseminated sulphides
CC0023R 41 42 89900 22900 23.40 1.31 10-15% chalcopyrite, 10-15% pyrite, 5-10% pyrrhotite Massive sulphide
CC0023R 42 43 81300 38800 24.30 0.83 10-15% chalcopyrite, 10-15% pyrite, 5-10% pyrrhotite Massive sulphide
CC0023R 43 44 67400 22800 22.30 1.37 10-15% chalcopyrite, 10-15% pyrite, 5-10% pyrrhotite Massive sulphide
CC0023R 44 45 18600 6240 6.75 0.17 5-10% pyrite and chalcopyrite, pyrrhotite, < 5% sphalerite Semi-massive sulphide
CC0023R 45 46 41800 8210 17.45 0.56 10-15% chalcopyrite, 10-15% pyrite, 5-10% pyrrhotite Massive sulphide
CC0023R 46 47 11650 3850 5.40 0.13 5-10% pyrite and chalcopyrite, pyrrhotite Semi-massive sulphide
CC0023R 47 48 36900 17850 21.30 0.33 10-15% chalcopyrite, 10-15% pyrite, 5-10% pyrrhotite Massive sulphide
CC0023R 48 49 102500 16750 32.50 0.73 10-15% chalcopyrite, 10-15% pyrite, 5-10% pyrrhotite Massive sulphide
CC0023R 49 50 43300 26400 20.70 0.53 10-15% chalcopyrite, 10-15% pyrite, 5-10% pyrrhotite Massive sulphide
CC0023R 49 50 34400 26200 17.70 0.55 Duplicate of previous sample Massive sulphide
CC0023R 50 51 75200 60400 30.60 0.38 10-15% chalcopyrite, 10-15% pyrite, 5-10% pyrrhotite Massive sulphide
CC0023R 51 52 3030 9010 2.00 0.05 < 5% pyrite and chalcopyrite Disseminated sulphides
CC0023R 52 53 2300 5840 1.39 0.03 < 5% pyrite and chalcopyrite Disseminated sulphides
CC0023R 56 57 23700 17700 9.41 0.30 5-10% pyrite and chalcopyrite, pyrrhotite, < 5% sphalerite Semi-massive sulphide
CC0023R 57 58 22000 34000 11.80 0.38 5-10% pyrite and chalcopyrite, pyrrhotite, < 5% sphalerite Semi-massive sulphide
CC0023R 72 73 4540 789 1.35 0.03 < 5% pyrite and chalcopyrite Disseminated sulphides
CC0023R 73 74 5830 1240 1.27 0.04 < 5% pyrite and chalcopyrite Disseminated sulphides
CC0023R 77 78 4050 732 1.81 0.03 < 5% pyrite and chalcopyrite Disseminated sulphides
CC0023R 85 86 12650 2980 12.60 0.31 5-10% pyrite and chalcopyrite, pyrrhotite Semi-massive sulphide
CC0023R 86 87 11150 3900 10.00 0.25 5-10% pyrite and chalcopyrite, pyrrhotite Semi-massive sulphide
CC0025R 90 91 45300 4050 9.71 0.40 10-15% chalcopyrite, 10-15% pyrite, 5-10% pyrrhotite Massive sulphide
CC0025R 91 92 20700 5960 6.80 0.13 5-10% pyrite and chalcopyrite, pyrrhotite Semi-massive sulphide
CC0025R 92 93 15000 4700 5.75 0.08 5-10% pyrite and chalcopyrite, pyrrhotite Semi-massive sulphide
CC0025R 103 104 8460 2400 11.80 0.13 < 5% pyrite and chalcopyrite Disseminated sulphides
CC0025R 104 105 12600 2940 3.62 0.09 5-10% pyrite and chalcopyrite, pyrrhotite Semi-massive sulphide
CC0025R 105 106 15400 5350 4.93 0.15 5-10% pyrite and chalcopyrite, pyrrhotite Semi-massive sulphide
TABLE D2-2: SIGNIFICANT INTERSECTIONS RC-DRILLING AT CANGAI & COMPARISON
OF XRF AND LAB (ALS) RESULTS
Hole ID From (m) To (m) Significant Intersections Significant Intersections
pXRF Result Lab Result (ALS Brisbane)
CRC001 40 45 5m @ 0.17% Cu & 0.06% Zn 5m @ 0.16% Cu & 0.99g/t Ag
(Composite sample*)
CRC002 52 58 MINING VOID MINING VOID
CRC003 67 68 1m @ 3.1% Cu & 0.5% Zn 1m @ 1.56% Cu, 3.71g/t Ag & 0.26% Zn
68 71 MINING VOID MINING VOID
CRC004 92 97 5m @ 1.3% Cu & 0.59% Zn 5m @ 1.56% Cu, 4.43g/t Ag & 0.4% Zn
94 97 Incl. 3m @ 1.6% Cu & 0.75% Zn Incl. 3m @ 2.22% Cu, 6.38g/t Ag & 0.60% Zn
97 98 MINING VOID MINING VOID
98 105 7m @ 0.45% Cu & 0.15% Zn 7m @ 0.29% Cu, 1.00g/t Ag & 0.20% Zn (Composite sample*)
CRC005 221 224 3m @ 1.7% Cu & 1.4% Zn 3m @ 1.76% Cu, 13.08g/t Ag & 1.33% Zn
221 222 Incl. 1m @ 2.6% Cu & 2.5% Zn incl. 1m @ 2.66% Cu, 20.70g/t Ag & 2.35% Zn
CRC006 69 73 4m @ 0.63% Cu & 0.46% Zn 4m @ 0.57% Cu, 3.34g/t Ag & 0.38% Zn
CRC007 107 111 MINING VOID MINING VOID
CRC008 210 213 3m @ 0.8% Cu & 0.36% Zn 3m @ 1.01% Cu, 6.60g/t Ag & 0.34% Zn
216 217 1m @ 0.4% Cu & 0.19% Zn 1m @ 0.56% Cu, 3.84g/t Ag & 0.21% Zn
228 232 4m @ 0.74% Cu & 0.29% Zn 4m @ 0.88% Cu, 5.43g/t Ag & 0.27% Zn
CRC009 100 102 2m @ 0.69% Cu & 0.18% Zn 2m @ 0.72% Cu, 3.32g/t Ag & 0.16% Zn
CRC010 145 147 2m @ 0.65% Cu & 0.19% Zn
CRC011 8 9 1m @ 0.15% Cu & 0.06% Zn
13 14 1m @ 0.09% Cu & 0.02% Zn
CRC012 9 11 2m @ 0.35% Cu & 0.08% Zn
CRC013 1 7 6m @ 1.90% Cu & 0.24% Zn
2 6 Incl. 4m @ 2.2% Cu & 0.27% Zn
CRC014 232 237 5m @ 0.31% Cu & 0.12% Zn
232 233 Incl. 1m @ 0.7% Cu & 0.12% Zn
234 235 Incl. 1m @ 0.3% Cu & 0.24% Zn
CRC015 0 13 13m @ 0.04% Cu & 0.05% Zn
CRC016 0 1 1m @ 0.72% Cu & 0.14% Zn
12 14 2m @ 0.11% Cu & 0.06% Zn
CRC017 4 7 3m @ 0.86% Cu & 0.13% Zn
CRC018 6 8 2m @ 0.73% Cu & 0.21% Zn
13 15 2m @ 1.17% Cu & 0.18% Zn
13 14 Incl. 1m @ 1.77% Cu & 0.2% Zn
33 35 2m @ 0.74% Cu & 0.31% Zn
38 42 4m @ 1.25% Cu & 0.62% Zn
39 40 Incl. 1m @ 3.7% Cu & 2.0% Zn
Notes:
1. * = Required 1m resampling
Source: CCZ geology team
FIGURE D2-5: RIG SETUP AT CRC001
Source: CCZ geology team
SECTION 3: ESTIMATION AND REPORTING OF MINERAL RESOURCES
(Criteria listed in section 1, and where relevant in section 2, also apply to
this section.)
Criteria / JORC Code Explanation Commentary
Database integrity Historical data from hard copy reports and electronic files such as excel and
word, have been captured within a Datamine GDB database. Historical data has
· Measures taken to ensure that data has not been corrupted by, for been reviewed by ROM Resources Geologists before entered, and cross referenced
example, transcription or keying errors, between its initial collection and with recent data. Data base checks have been run by ROM Resources geologists
its use for Mineral Resource estimation purposes. before resource estimation commenced. Where the location of historical drill
holes was in question they have been removed from the model. Reported
· Data validation procedures used. collars have been adjusted to the topography model (drone) where the
discrepancy is ±0.2m.
Site visits Mr Mark Biggs visited site three times during 2017-2018 to observe the geology
and the initial exploration programme, as well as drilling and sampling
· Comment on any site visits undertaken by the Competent Person and the procedures (Biggs, 2021). Recommendations to: (1) collect additional bulk
outcome of those visits. density data from mineralised lodes; and (2) employ triple tube diamond
drilling methods and in split logging for geotechnical holes have since been
· If no site visits have been undertaken indicate why this is the case. implemented. No other material issues were noted.
Geological interpretation The deposits have been interpreted on vertical oblique sections at variable
spacing by reviewing geological logging and copper grades, as well as
· Confidence in (or conversely, the uncertainty of) the geological considering interpretations from historic mining reports and previously mined
interpretation of the mineral deposit. voids. Confidence is moderate in areas of close-spaced drilling.
· Nature of the data used and of any assumptions made. Data has been supplied as a drill hole database, including collar, survey,
lithology, weathering, and assay data.
· The effect, if any, of alternative interpretations on Mineral
Resource estimation. Magnetic susceptibility readings completed on the RC chips have not uniquely
characterised mineralised zones, either within or outside the named lenses'
· The use of geology in guiding and controlling Mineral Resource wireframes. The felsic dyke is characterised by 3x higher Ca assay values.
estimation.
Alternate correlations of lodes between drill holes are possible in some
· The factors affecting continuity both of grade and geology. places but would not materially affect the Mineral Resource estimate.
Mineralised lodes have been interpreted using a 0.1% nominal copper cut off
and aided with the use of lithology, veining, and structure to help identify
the key shear structures.
Potentially economic mineralisation not always restricted to an easily
identifiable sheared, porphyritic syenite or diorite. Within the lodes
higher grade copper (>2%) is erratically distributed.
The main lode wireframe includes some barren material between copper
mineralisation.
Due to its narrow nature the orientation of interpreted lode wireframes can be
influenced locally due to the accuracy of down-hole surveys.
Dimensions The extent of mineralisation with Cu >500ppm below the original topography
is:
· The extent and variability of the Mineral Resource expressed as
length (along strike or otherwise), plan width, and depth below surface to the Main Strike = 955m, Depth = 290m, Width = 1 to 35m.
upper and lower limits of the Mineral Resource.
Mineralisation extends significantly downdip from the historical pit floor for
the main lode.
Estimation and modelling techniques Block grade estimation for Cu was by inverse distance squared methods (ID2).
ID2 was considered suitable for the style of mineralisation, size of blocks
· The nature and appropriateness of the estimation technique(s) applied relative to the drill hole spacing, and the assumed open pit and underground
and key assumptions, including treatment of extreme grade values, domaining, mining selectivity.
interpolation parameters and maximum distance of extrapolation from data
points. If a computer assisted estimation method was chosen include a Drill holes were composited to 1m, and data was interpolated using Datamine
description of computer software and parameters used. Minescape Block Model software.
· The availability of check estimates, previous estimates and/or mine Hard boundaries were adopted for lode wireframes, with each lode estimated
production records and whether the Mineral Resource estimate takes appropriate independently.
account of such data.
No blocks outside the line of lode mask were estimated.
· The assumptions made regarding recovery of by-products.
Blocks were estimated using 1 - 8 samples with a maximum of 2 samples from any
· Estimation of deleterious elements or other non-grade variables of one drill hole.
economic significance (eg sulphur for acid mine drainage characterisation).
A two-pass search strategy was employed with search ellipsoids orientated in
· In the case of block model interpolation, the block size in relation accordance with the average lode orientation.
to the average sample spacing and the search employed.
Main Lode:
· Any assumptions behind modelling of selective mining units.
Maximum search distance of 45m by 25m by 2m for search pass 1.
· Any assumptions about correlation between variables.
Maximum search distance of 90m by 65m by 8m for search pass 2.
· Description of how the geological interpretation was used to control
the resource estimates.
· Discussion of basis for using or not using grade cutting or capping.
· The process of validation, the checking process used, the comparison
of model data to drill hole data, and use of reconciliation data if available.
Moisture Resource tonnages are estimated on a dry in situ basis (air-dried).
· Whether the tonnages are estimated on a dry basis or with natural
moisture, and the method of determination of the moisture content.
Cut-off parameters Reporting cut-off grades of 0.2% Cu for open pit and will require confirmation
through feasibility work. For the channel samples in the oxidized zone a
· The basis of the adopted cut-off grade(s) or quality parameters top-cut of 15% Cu was applied, whereas for fresh mineralisation no top-cut was
applied. applied.
Mining factors or assumptions Cangai has previously been selectively mined by open cut mining methods. A
total of 5,080t of ore @ 8% Cu has been deducted from the resource estimate to
· Assumptions made regarding possible mining methods, minimum mining reflect this.
dimensions and internal (or, if applicable, external) mining dilution. It is
always necessary as part of the process of determining reasonable prospects Portions of the remaining resources are considered to have sufficient grade
for eventual economic extraction to consider potential mining methods, but the and continuity to be considered for both selective open cut and underground
assumptions made regarding mining methods and parameters when estimating mining but will require confirmation through feasibility work.
Mineral Resources may not always be rigorous. Where this is the case, this
should be reported with an explanation of the basis of the mining assumptions No mining parameters or modifying factors have been applied to the Mineral
made. Resources.
Metallurgical factors or assumptions Since the 2017 maiden mineral resource estimate, some metallurgical testing
has taken place. Two composites formed from bulk samples taken in April 2018
· The basis for assumptions or predictions regarding metallurgical from McDonough's Portal and Shaft stockpiles along the line of lode (Castillo
amenability. It is always necessary as part of the process of determining Copper 2018a) have been the focal point of metallurgical test-work. The
reasonable prospects for eventual economic extraction to consider potential test-work in the laboratory has demonstrated the ore has beneficiated
metallurgical methods, but the assumptions regarding metallurgical treatment materially. Furthermore, results to date have confirmed solid copper
processes and parameters made when reporting Mineral Resources may not always concentrate recoveries that exceeded 80%, while the grade was up to 22% Cu and
be rigorous. Where this is the case, this should be reported with an Co 300ppm.
explanation of the basis of the metallurgical assumptions made.
In September 2019 assay results for samples collected from legacy stockpiles
at Smelter Creek Slag stockpile and another composite along the line of lode
(Marks and McDonough's dumps) were received back from the Peacocke &
Simpson Laboratory in Zimbabwe, with average head grades at 1.23% and 2.03% Cu
respectively.
Further work completed in December 2019, using a representative insitu massive
sulphide ore sample extracted from drillhole CC0023R completed in August 2018,
reported a commercial grade concentrate of 22.2% Cu & 7.4% Zn with a
recovery of 79.3% of total contained copper was achieved, which is in line
with previous investigations. The following observations were made:
• This result was derived from using standard
metallurgical flotation methods; and
• The result is highly encouraging as it provides
first-hand insight on a potential final copper concentrate product from using
high-grade CCM ore.
• The composite sample utilised in the metallurgical
test-work process comprised high-grade massive sulphide RC chips with a head
grade of 8.18% Cu and 4.36% Zn.
Environmental factors or assumptions The historical Cangai Mine is a series of lapsed Mining Licenses with an EA in
place (only on the EL).
· Assumptions made regarding possible waste and process residue
disposal options. It is always necessary as part of the process of determining Historically, ore processing and tailings storage has been conducted off-site,
reasonable prospects for eventual economic extraction to consider the various third-party options are available for offsite ore processing and
potential environmental impacts of the mining and processing operation. While tailings storage.
at this stage the determination of potential environmental impacts,
particularly for a greenfields project, may not always be well advanced, the Mining has previously taken place at Cangai with no significant environmental
status of early consideration of these potential environmental impacts should impediments.
be reported. Where these aspects have not been considered this should be
reported with an explanation of the environmental assumptions made.
Bulk density During the modelling exercise discrepancies were found where the existing
specific gravity water displacement testing undertaken on site in 2018 were at
· Whether assumed or determined. If assumed, the basis for the odds with detailed density analysis conducted on slag and ex-mine dump bulk
assumptions. If determined, the method used, whether wet or dry, the frequency samples collected for the purpose of metallurgical recovery testing.
of the measurements, the nature, size and representativeness of the samples.
A new programme of specific gravity testing was undertaken on stored HQ
· The bulk density for bulk material must have been measured by methods diamond core from CC0035D and CC0036D focusing on dual water (Fieldcrew) and
that adequately account for void spaces (vugs, porosity, etc), moisture and alcohol methods (ALS Brisbane). Comparisons were also made to lithology,
differences between rock and alteration zones within the deposit. state of weathering, and copper content.
· Discuss assumptions for bulk density estimates used in the evaluation Specific gravity (SG) for rock and pulp samples can be measured by different
process of the different materials. methods. A rock sample can be submersed in water, either as submitted or
covered with paraffin wax. As a pulp sample can't be submerged in water,
specific gravity measurements are taken by using a pycnometer.
For 25 HQ core samples (CC0035D and 36D) good correlation was found between
the two SG methodologies, one conducted on site by Fieldcrew personnel and the
other at ALS Brisbane using method "OA-GRA08b" (see attached graph).
Comparison of the ALS SG results, and trace copper (in ppm) showed a very
strong logarithmic correlation (see attached graph)
Classification The insitu resources were classified on a block-by-block basis using
estimation outputs. Inferred Resource blocks required the closest sample
· The basis for the classification of the Mineral Resources into within 45m, an average sample distance <90m, and a minimum of 2 drill
varying confidence categories. holes, with the remaining blocks assigned to Exploration Target ranges (not
reported here).
· Whether appropriate account has been taken of all relevant factors
(ie relative confidence in tonnage/grade estimations, reliability of input The resource classification appropriately reflects the Competent Person's view
data, confidence in continuity of geology and metal values, quality, quantity of the deposit.
and distribution of the data).
· Whether the result appropriately reflects the Competent Person's view
of the deposit.
Audits or reviews The Cangai Mineral Resource estimate was reviewed by a specialist
consultant. Their report found agreement in some of the modelling
· The results of any audits or reviews of Mineral Resource estimates. assumptions, but disagreed with the use of channel samples and the modelled
width of various ore lenses.
Discussion of relative accuracy/ confidence The relative accuracy of the Mineral Resource estimate is reflected in the
reporting of the Mineral Resource as per the guidelines of the 2012 JORC Code.
· Where appropriate a statement of the relative accuracy and confidence
level in the Mineral Resource estimate using an approach or procedure deemed Detailed statistical and geostatistical methods to quantify the relative
appropriate by the Competent Person. For example, the application of accuracy of the resource have not been undertaken. However, preliminary
statistical or geostatistical procedures to quantify the relative accuracy of statistical analysis suggests the relative error of this estimate to be
the resource within stated confidence limits, or, if such an approach is not ±20-30%
deemed appropriate, a qualitative discussion of the factors that could affect
the relative accuracy and confidence of the estimate. Lode geometry and grade can vary significantly over short distances, but
continuity of mineralisation and grade is supported by close-spaced drilling
· The statement should specify whether it relates to global or local in areas classified as Inferred.
estimates, and, if local, state the relevant tonnages, which should be
relevant to technical and economic evaluation. Documentation should include Drill hole data was collected and analysed using prevailing industry practices
assumptions made and the procedures used. but a small amount of drilling pre-dates 1990. There is a small
possibility of the resource including minor amounts of undocumented
· These statements of relative accuracy and confidence of the estimate underground voids from historical mining, as post mining drilling did
should be compared with production data, where available. intersect underground voids in seven (7) instances.
The resource statement relates to the global resource estimate. The grade
cut-offs and depth of potential open pit material used to determine the
Mineral Resource were assumed and require confirmation through feasibility
work.
The deposit is not currently being mined, but the resource estimate has a
lower average grade than production records for the same mineralisation zone
that was mined at higher elevations from 1903 - 1917 and 1934 - 1937.
During its lifecycle, the Cangai Copper Mine produced 5,080 tonnes of copper,
1,035kg of silver and 527kg of gold from a total underground extraction of
307,000t of which approximately 63,500t was ore (this equates to 8% Cu, 1.5g/t
Au and 15g/t Ag as provided by GSNSW MinView portal).
This information is provided by RNS, the news service of the London Stock Exchange. RNS is approved by the Financial Conduct Authority to act as a Primary Information Provider in the United Kingdom. Terms and conditions relating to the use and distribution of this information may apply. For further information, please contact
rns@lseg.com (mailto:rns@lseg.com)
or visit
www.rns.com (http://www.rns.com/)
.
RNS may use your IP address to confirm compliance with the terms and conditions, to analyse how you engage with the information contained in this communication, and to share such analysis on an anonymised basis with others as part of our commercial services. For further information about how RNS and the London Stock Exchange use the personal data you provide us, please see our
Privacy Policy (https://www.lseg.com/privacy-and-cookie-policy)
. END MSCEZLFLXDLBBBBRecent news on Castillo Copper
See all newsREG - Castillo Copper Ltd - March 2024 Quarterly Activities Report
AnnouncementREG - Castillo Copper Ltd - Completion of Sale of Broken Hill Licenses
AnnouncementREG - Castillo Copper Ltd - Initial and Final Director’s Interest Notice
AnnouncementREG - Castillo Copper Ltd - Half-year Financial Report
AnnouncementREG - Castillo Copper Ltd - Board Changes
Announcement