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 108,000t1), 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 |
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| (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 |
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| (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 |
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| 199,000 | 1.35 | 0.02 | 1.9 | 0.1 | 4.6 | 2,687 | 48 | 3,781 | 20 | 915 |
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| 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 conductors2, 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 MINE1,2,7
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% Cu4. 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 RECONCILIATION4
| 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
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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 techniques5.
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 307,000t4.6. 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 portal4,6).
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 Mine5:
· 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 sphalerite6.
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 INTERCEPTS1,2,7
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 Beds7.
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 intrusion7.
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 checks7.
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 testing7.
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 analysis7.
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 sections7.
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 diameters7.
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 ± 7m7.
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 lode7 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 300ppm7.
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 respectively7.
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 investigations7. 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% Zn7.
For further information, please contact:
| Castillo Copper Limited | +61 8 6558 0886 |
| Dr Dennis Jensen (Australia), Managing Director Gerrard Hall (UK), Chairman |
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| SI Capital Limited (Financial Adviser and Corporate Broker) | +44 (0)1483 413500 |
| Nick Emerson |
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| Gracechurch Group (Financial PR) | +44 (0)20 4582 3500 |
| Harry Chathli, Alexis Gore, Henry Gamble |
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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=
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, 2nd August 2018, 25pp.
e. Castillo Copper Limited, 2018b, ASX Release - Cangai update: Down-hole electromagnetic surveys completed at Volkhardt's Lode, 24th 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
APPENDIX A: CANGAI COPPER MINE DRILL-HOLE DATA
FIGURE A1: DRILLHOLES USED IN THE MODEL
| Hole | MGA56 Easting | MGA56 Northing | AHD | Depth | INC | Grid Azimuth | Source | Type |
| 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 specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc.). These examples should not be taken as limiting the broad meaning of sampling. • Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. • Aspects of the determination of mineralisation that are Material to the Public Report. In cases where 'industry standard' work has been done this would be relatively simple (e.g., 'reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30-g charge for fire assay'). In other cases, more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (e.g., submarine nodules) may warrant disclosure of detailed information. | Samples from the 2017-2018 Cangai drilling programme were collected using the reverse circulation method of drilling on a 1 metre basis. Initially 20-25kg of chips and dust was collected and riffled down to a 2-3kg sample for further lab analysis.
Field samples were firstly analysed with a Niton portable XRF device to determine compositing rules.
Subsequently, sample advice forms were coded with all samples were delivered, initially to ALS Orange laboratory and in Stage 2 to ALS Laboratory in Brisbane QLD where the lab undertook the splitting and compositing of the 5m composite samples and completed multi-element analysis on the 5m composite and 1m selected samples. |
| ||||
| Drilling techniques | • Drill type (e.g., core, reverse circulation, open hole hammer, rotary air blast, auger, Bangka, sonic, etc.) and details (e.g. core diameter, triple or standard tube, depth of diamond tails, face sampling bit or other type, whether core is oriented and if so, by what method, etc.). | Drilling was provided by Budd Drilling using a modified track mounted UDH RC rig as illustrated below by Figure D1-1. Both reverse circulation and diamond coring techniques were employed during the drilling programme. FIGURE D1-1 BUDD DRILLING AT CANGAI
|
| ||||
| 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.
| Sample recovery was generally 90-100% for each metre except when mining cavities (workings >1m wide) were intersected. Intersecting these mining voids generally stopped drilling due to a loss of circulation and uncontrolled hole deviation. |
| ||||
| 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
| All drilling has been completed to high modern-day standard by a competent field teams & drill crew.
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 sample on 1m intervals for future reference as illustrated below in Figure D1-2.
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. 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. | 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 to test the samples for mineralisation to determine which samples are tested as individual metres and which samples are to be composited into 5m samples. Composite samples were homogenized, and riffle split at the labs prior to assaying.
Industry acceptable standards and blanks were used as certified reference material to ensure satisfactory performance of the laboratory. Duplicates were inserted in at a ratio of 1:20 of normal sampling. 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 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 (e.g., standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (i.e., lack of bias) and precision have been established.
| Multi-suite analysis methodology (ME-MS61) which involves a four-acid 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, Hg, Zn, W, Cu, Ni, Co, V, Ti, Au, Ga, Ge, LI, La, Fe, Mn, Cr, Sc, Mo, Th, U, Ta.
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 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. | All significant intercepts have been verified by two people, one ROM and one 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 conducted as in internal check prior to sending samples for laboratory analysis. Reading times using 2 beam "Geochem Mode" was employed via 30sec/beam for a total of 60 sec. All logging and sampling data is collected, and data entered onto Excel 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 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.
| Drill pads were initial located using an RTK differential GPS. Drillholes collar locations have been picked using a Garmin handheld GPS to +4m. At completion, all drillholes were accurately surveyed. Collars RLs were corrected and tagged to a recently completed Drone DTM topography model which has accuracies for AHD of ±0.2m. |
| ||||
| 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. | Drillholes CC0019R was abandoned after 36m due to Rig problems. Drillhole CC0020R deviated too much from the original plan and was abandoned at 155m.
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 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 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 drilling was originally planned to intersect workings and drill into data gaps between orebodies such that in general the intersections are where possible (due to restricted access) perpendicular to a strike of 126 degrees (see Table D1-1). Additional surface bedding and foliation data, and that from some of the 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 Easting | MGA56 Northing | AHD | Depth | INC | Grid Azimuth | Source | Type |
| 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 agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. • The security of the tenure held at the time of reporting along with any known impediments to obtaining a licence to operate in the area. | • Castillo Copper holds 100% of EL 8625 & EL 8635. The tenure has been granted for a period of thirty-six months until 17th July 2020, for Group 1 minerals. The location of the tenure is shown in Figure D2-1 below: FIGURE D2-1: LOCATION OF EL 8625 AND EL8635 JACKADERRY SOUTH
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 Information | A summary of all information material to the understanding of the exploration results including a tabulation of the following information for all Material drill holes: • easting and northing of the drill hole collar • elevation or RL (Reduced Level - elevation above sea level in metres) of the drill hole collar • dip and azimuth of the hole • down hole length and interception depth • hole length. 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 | All historical holes were used except BJAC1 and 2, which were drilled outside the block model boundaries. Drill hole collar summary and intersection summary tables are included as Appendix A in this report and progressively in various Castillo Copper ASX release throughout 2018. Mineralised zones are identified by the field geologist and flagged as geological/mineralised zones as shown in Table D2-1 at the end of this section. | ||||
| Data aggregation methods | In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g., cutting of high grades) and cut-off grades are usually Material and should be stated. Where aggregate intercepts incorporate short lengths of high-grade results and longer lengths of low-grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail. The assumptions used for any reporting of metal equivalent values should be clearly stated. | No top cuts have been applied to reporting of the significant Intersections and lower cut of 0.2% (2,000ppm) Cu has generally been used. Full detailed assay intervals for the key elements are included in the Appendices of the Cangai CP report.
Summary Intersections per 2017 to 2018 drillhole have been reported based on 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 Results. If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (e.g. 'down hole length, true width not known'). | All intersections are reported as downhole widths. Once assays are returned and the geological controls are fully established, the 3D modelling package will determine true widths. The Lode is currently modelled to be sub-vertical to vertical, striking 126 degrees and pitching at 60 degrees west. Varies from 0.3m-5.2m wide. The main 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 should be included for any significant discovery being reported These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views. | Appropriate diagrams have been included in the body text (Appendix B) of this announcement and previous ASX announcements (see references). | ||||
| Balanced reporting | Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced avoiding misleading reporting of Exploration Results. | All drillholes completed to date have been reported in various Castillo Copper ASX releases. | ||||
| Other substantive exploration data | Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. | Historical explorers have also conducted airborne and ground gravity, magnetic, EM, and resistivity surveys over parts of the tenure area but this is yet to be collated. A surface EM Survey has been undertaken and has been previously reported (multiple conductors discovered from FLEM survey (Castillo Copper 8th January 2018 ASX Release). Castillo Copper also conducted DHEM surveys on eight (8) drillholes, two of which produced EM anomalies modelled as plates by the Maxwell software | ||||
| Future Work | The nature and scale of planned further work (e.g., tests for lateral extensions or depth extensions or large-scale step-out drilling). Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive. | CCZ's geology team have mapped out the next drilling campaign that will specifically target extending the known copper orebody (Figure A2-4) through the following actions, Targeting the following locations:
• 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 pXRF Result | Significant Intersections 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 · Measures taken to ensure that data has not been corrupted by, for example, transcription or keying errors, between its initial collection and its use for Mineral Resource estimation purposes. · Data validation procedures used. | 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 been reviewed by ROM Resources Geologists before entered, and cross referenced with recent data. Data base checks have been run by ROM Resources geologists before resource estimation commenced. Where the location of historical drill holes was in question they have been removed from the model. Reported collars have been adjusted to the topography model (drone) where the discrepancy is ±0.2m. |
| Site visits · Comment on any site visits undertaken by the Competent Person and the outcome of those visits. · If no site visits have been undertaken indicate why this is the case. | 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 procedures (Biggs, 2021). Recommendations to: (1) collect additional bulk density data from mineralised lodes; and (2) employ triple tube diamond drilling methods and in split logging for geotechnical holes have since been implemented. No other material issues were noted. |
| Geological interpretation · Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. · Nature of the data used and of any assumptions made. · The effect, if any, of alternative interpretations on Mineral Resource estimation. · The use of geology in guiding and controlling Mineral Resource estimation. · The factors affecting continuity both of grade and geology. | The deposits have been interpreted on vertical oblique sections at variable spacing by reviewing geological logging and copper grades, as well as considering interpretations from historic mining reports and previously mined voids. Confidence is moderate in areas of close-spaced drilling. Data has been supplied as a drill hole database, including collar, survey, lithology, weathering, and assay data. Magnetic susceptibility readings completed on the RC chips have not uniquely characterised mineralised zones, either within or outside the named lenses' wireframes. The felsic dyke is characterised by 3x higher Ca assay values. Alternate correlations of lodes between drill holes are possible in some 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 and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource. | The extent of mineralisation with Cu >500ppm below the original topography is: Main Strike = 955m, Depth = 290m, Width = 1 to 35m. Mineralisation extends significantly downdip from the historical pit floor for the main lode. |
| Estimation and modelling techniques · The nature and appropriateness of the estimation technique(s) applied and key assumptions, including treatment of extreme grade values, domaining, interpolation parameters and maximum distance of extrapolation from data points. If a computer assisted estimation method was chosen include a description of computer software and parameters used. · The availability of check estimates, previous estimates and/or mine production records and whether the Mineral Resource estimate takes appropriate account of such data. · The assumptions made regarding recovery of by-products. · Estimation of deleterious elements or other non-grade variables of economic significance (eg sulphur for acid mine drainage characterisation). · In the case of block model interpolation, the block size in relation to the average sample spacing and the search employed. · Any assumptions behind modelling of selective mining units. · Any assumptions about correlation between variables. · 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. | Block grade estimation for Cu was by inverse distance squared methods (ID2). ID2 was considered suitable for the style of mineralisation, size of blocks relative to the drill hole spacing, and the assumed open pit and underground mining selectivity. Drill holes were composited to 1m, and data was interpolated using Datamine Minescape Block Model software. Hard boundaries were adopted for lode wireframes, with each lode estimated independently. No blocks outside the line of lode mask were estimated. Blocks were estimated using 1 - 8 samples with a maximum of 2 samples from any one drill hole. A two-pass search strategy was employed with search ellipsoids orientated in accordance with the average lode orientation. Main Lode: Maximum search distance of 45m by 25m by 2m for search pass 1. Maximum search distance of 90m by 65m by 8m for search pass 2. |
| Moisture · Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. | Resource tonnages are estimated on a dry in situ basis (air-dried). |
| Cut-off parameters · The basis of the adopted cut-off grade(s) or quality parameters applied. | 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 top-cut of 15% Cu was applied, whereas for fresh mineralisation no top-cut was applied. |
| Mining factors or assumptions · Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating 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 made. | 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 reflect this. Portions of the remaining resources are considered to have sufficient grade and continuity to be considered for both selective open cut and underground mining but will require confirmation through feasibility work. No mining parameters or modifying factors have been applied to the Mineral Resources. |
| Metallurgical factors or assumptions · The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. | Since the 2017 maiden mineral resource estimate, 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 (Castillo Copper 2018a) 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. 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 · Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made. | The historical Cangai Mine is a series of lapsed Mining Licenses with an EA in place (only on the EL). Historically, ore processing and tailings storage has been conducted off-site, various third-party options are available for offsite ore processing and tailings storage. Mining has previously taken place at Cangai with no significant environmental impediments. |
| Bulk density · Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, the frequency of the measurements, the nature, size and representativeness of the samples. · The bulk density for bulk material must have been measured by methods that adequately account for void spaces (vugs, porosity, etc), moisture and differences between rock and alteration zones within the deposit. · Discuss assumptions for bulk density estimates used in the evaluation process of the different materials. | During the modelling exercise discrepancies were found where the existing specific gravity water displacement testing undertaken on site in 2018 were at odds with detailed density analysis conducted on slag and ex-mine dump bulk samples collected for the purpose of metallurgical recovery testing. A new programme of specific gravity testing was undertaken on stored HQ diamond core from CC0035D and CC0036D focusing on dual water (Fieldcrew) and alcohol methods (ALS Brisbane). Comparisons were also made to lithology, state of weathering, and copper content. Specific gravity (SG) for rock and pulp samples can be measured by different 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)
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| Classification · The basis for the classification of the Mineral Resources into varying confidence categories. · Whether appropriate account has been taken of all relevant factors (ie relative confidence in tonnage/grade estimations, reliability of input data, confidence in continuity of geology and metal values, quality, quantity and distribution of the data). · Whether the result appropriately reflects the Competent Person's view of the deposit. | The insitu resources were classified on a block-by-block basis using estimation outputs. Inferred Resource blocks required the closest sample within 45m, an average sample distance <90m, and a minimum of 2 drill holes, with the remaining blocks assigned to Exploration Target ranges (not reported here). The resource classification appropriately reflects the Competent Person's view of the deposit. |
| Audits or reviews · The results of any audits or reviews of Mineral Resource estimates. | The Cangai Mineral Resource estimate was reviewed by a specialist consultant. Their report found agreement in some of the modelling assumptions, but disagreed with the use of channel samples and the modelled width of various ore lenses. |
| Discussion of relative accuracy/ confidence · Where appropriate a statement of the relative accuracy and confidence level in the Mineral Resource estimate using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate. · The statement should specify whether it relates to global or local estimates, and, if local, state the relevant tonnages, which should be relevant to technical and economic evaluation. Documentation should include assumptions made and the procedures used. · These statements of relative accuracy and confidence of the estimate should be compared with production data, where available. | 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. Detailed statistical and geostatistical methods to quantify the relative accuracy of the resource have not been undertaken. However, preliminary statistical analysis suggests the relative error of this estimate to be ±20-30% Lode geometry and grade can vary significantly over short distances, but continuity of mineralisation and grade is supported by close-spaced drilling in areas classified as Inferred. Drill hole data was collected and analysed using prevailing industry practices but a small amount of drilling pre-dates 1990. There is a small possibility of the resource including minor amounts of undocumented underground voids from historical mining, as post mining drilling did 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). |
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