Visible copper intercepts continue at Big One

·      Reverse Circulation, RC, drilling and sampling techniques employed for the first 13 holes (of a 35-hole program) currently completed at the Big One Deposit by CCZ.

·      Samples were taken off a cyclone for every metre drilled, put through a three tier, 87.5/12.5 splitter where approximately 2.5 kg of RC chip samples were collected for every metre drilled. The remainder was bagged separately and stored in case additional sub sampling is required soon.

·      Samples were also composited very four metres and all samples were collected to maximise optimal representation for each sample.

·      Each metre sample had an amount removed for washing and cleaning and sieving then place into metre allocated chip trays. These chips were logged on site by the rig geologists and those logs have been saved into a spreadsheet and stored on the Company server. Any visible mineralisation, alteration or other salient features were recorded in the logs. Industry wide, acceptable, standard practices were adhered to for the drilling and sampling of each metre as per the Drilling and Sampling Procedures set out before commencement of the drilling programme.

·      Reverse Circulation drilling used for first 13 holes at Big One Deposit.

·      The reader of the current ASX Release is referred to the CCZ's first publication of the geological diagrams and associated information: (1) "Final targets completed for drilling campaigns at Arya and Big One Deposit" released on the ASX by CCZ on the 14-July-2020. (2) "Field analysis verifies high-grade copper with newly identified gold mineralisation at Big One" released on the ASX by CCZ on the 14-Sep-2020.

·      Within acceptable, industry standard limits, all samples collected were of near equal mass and recoveries were also within acceptable limits for RC drilling and all recorded in the daily logs. Every effort was made on site to maximise recovery including cleaning out the sample trays, splitter and cyclone and ensuring that the drillers progressed at a steady constant rate in order for the rig to easily complete each metre effectively.

·      Every metre drilled and sampled was logged geologically in accordance with industry- wide acceptable standard for RC logging and the logging was qualitative in nature with every metre logged.

·      CCZ's first 13 RC holes have been assayed by an independent laboratory, ALS. Methods used were as follows:

·      Gold - by method Au-AA25 30g charge (fire Assay with AAS finish);

·      High gold values within oxide zone/supergene zone may need further testing by method Au-SCR21;

·      Copper and 32 other - by method ME-ICP61 (HF-HN03-HCL04 acid digest, HCL leach and ICP-AES finish);

·      Over limit copper (>10,000 ppm [0.01%]) to be re assayed for copper - by method Cu-OC62 (HF-HN03-HCL04 acid digest, HCL leach and ICP- AES finish).

These analytical methods are widely considered as suitable and appropriate for this type of mineralisation.

·      For historical assaying, the assays were done by Independent Laboratory (ALS). All elements except for gold were analysed by method ME ICP41 (35 element testing via Aqua Regia digest then ICP-AES) and with many copper assays greater than 1%, the copper was redone using method Cu-OG46 with ICP-AES. The gold was done by fire assay method AA25. All methods used were both suitable and appropriate for the styles of mineralisation present in the Big One Deposit.

·      CCZ's first four (4) RC hole assay results from ALS have been reviewed by two independent consultant geologists.

·      For historical drilling, Independent Laboratory assaying by ALS has confirmed, within acceptable limits, the occurrences of high-grade copper inferred from the initial XRF readings. Laboratory standards and duplicates were used in accordance with standard procedures for geochemical assaying. For the first seven holes of the current drilling programme, ALS has confirmed the copper assay results that were greater than 10 000 pppm or 0.1% Cu.

·      The first 13 RC holes done by CCZ have had their location surveyed by GPS and these have now been surveyed by differential GPS by independent licensed surveyors.

·      The spatial location for the first seven holes have been differentially surveyed into the National Grid System.

·      The first 13 RC holes were part of a 35-hole program that was set out on a nominal 50m pattern. At the completion of all the planned holes, the drillhole collars will be differentially surveyed by independent, licensed surveyors and the grid pattern verified.

·      The spatial location for the photographs collected during the preliminary site visit at the Big One Deposit were collected at two previously mined sites that exposed the copper mineralisation. The preliminary site visit was brief, in a limited time inspection of the Big One Deposit with the Landholder, therefore the full 600m strike length of the surface mineralisation is yet to be observed, the observations completed on the 05-August-2020 showed prospective copper mineralisation within one of the mined pits and the greater Big One Deposit area is anticipated to undergo a widespread reconnaissance during the pegging of the Big One Deposit drill sites.

·      The 05-August-2020 observed mineralisation included:

o  Location 01 (Figure 1, left photo, in ASX Release body): View looking east-northeast in the main excavated pit at the Big One Mine sub-parallel to the strike of the mineralisation, steep dip to the south-east dipping, which includes a copper carbonate mineralised fault breccia zone;

o  Location 02 (Figure 1, right photo, in ASX Release body):  View looking west-south-west, the same sub-vertical structure looking south in a second pit following the strike trend in the opposite direction to the first pit; the host sediments are strongly hematite stained (non-magnetic), it is possible the mineralisation had been fully excavated here;

o  Location 03 (Figure 2, left photo, in ASX Release body):   Malachite (green) and Azurite (blue) as staining and fracture fill in this case, in fault brecciated siltstone. Most likely this had spalled off the mineralised zone, located as in pit float material. Green malachite and blue azurite are common as breccia and slicken side fracture fill; and

o  Location 04 (Figure 2, right photo, in ASX Release body):   Malachite (green) as a crystalline coating/fracture infill on haematite-stained siltstone. Most likely this had spalled off the mineralised zone, located as in pit float material.

·      The current CCZ RC drilling programme has had all holes oriented to intersect the mineralised structure/zone subsurface perpendicularly and therefore does not constitute any perceived bias.

·      Rock chip samples were taken at areas of interest from observed mineralisation along the line of lode of the mineralised dyke, secondary structures, and surrounding spoil heaps.

·      Each day's RC samples were removed from site and stored in a secure location off site.

·      The rock chip samples taken during the recent field trip were securely locked within the vehicle on site until delivered to Mt Isa for dispatch to the laboratory in person by the field personnel.

·      The following mineral tenures are held 100% by subsidiaries of Castillo Copper Limited, totalling an area of 736.8 km² in the "Mt Oxide project":

o  EPM 26574 (Valparaisa North) - encompasses the Big One historical mineral resource, Holder Total Minerals Pty Ltd, Granted 12-June-2018 for a 5 year period over 100 sub-blocks (323.3Km²), Expires 11-June-2023;

o  EPM 26462 (Big Oxide North) - encompasses the 'Boomerang' historical mine and the 'Big One' historical mine, Holder: QLD Commodities Pty Ltd, Granted: 29-Aug-2017 for a 5 year period over 67 sub-blocks (216.5Km²), Expires: 28-Aug-2022;

o  EPM 26525 (Hill of Grace) - encompasses the Ayra significant aeromagnetic anomaly, Holder: Total Minerals Pty Ltd for a 5 year period over 38 sub-blocks (128.8Km²), Granted: 12-June-2018, Expires: 11-June-2023;

o  EPM 26513 (Torpedo Creek/Alpha Project) - Granted 13-Aug-2018 for a 5-year period over 23 sub-blocks (74.2Km²), Expires 12-Aug-2023; and

o  EPMA 27440 (The Wall) - An application lodged on the 12-Dec-2019 over 70 sub-blocks (~215Km²) by Castillo Copper Limited.

·      A check on the tenures in 'application status' was completed in 'GeoResGlobe' on the 23rd-September-2020. 

·      Historical QDEX / mineral exploration reports have been reviewed for historical tenures that cover or partially cover the Project Area in this announcement. Federal and State Government reports supplement the historical mineral exploration reporting (QDEX open file exploration records).

·      Most explorers were searching for Cu-Au-U, and in particular, proving satellite deposit style extensions to the several small sub-economic copper deposits (e.g. Big Oxide and Josephine).

·      With the Mt Oxide Project in regional proximity to Mt Isa and numerous historical and active mines, the Project area has seen portions of the historical mineral tenure subject to various styles of surface sampling, with selected locations typically targeted by shallow drilling (Total hole depth is typically less than 50m).

·      The Mt Oxide project tenure package has a significant opportunity to be reviewed and explored by modern exploration methods in a coherent package of EPM's, with three of these forming a contiguous tenure package.

·      Various Holders and related parties of the 'Big One' historical mining tenure (ML8451) completed a range of mining activities and exploration activities on what is now the 'Big One' prospect for EPM 26462. The following unpublished work is acknowledged (and previously shown in the reference list):

o  West Australian Metals NL, 1994. Drill Programme at the "Big One" Copper Deposit, North Queensland for West Australian Metals NL.

o  Wilson, D., 2011. 'Big One' Copper Mine Lease 5481 Memorandum - dated 7 May 2011.

o  Wilson, D., 2015. 'Big One' Mining Lease Memorandum - dated 25 May 2015: and

o  Csar, M, 1996. Big One & Mt Storm Copper Deposits. Unpublished field report.

·      The reader of the current ASX Release is referred to the CCZ's first publication of the 1993 historical reverse circulation drilling results for additional diagrams and drilling information: "Historic drill data verifies grades up to 28.40% Cu from <50m in supergene ore at Mt Oxide Pillar" released on the ASX by CCZ on the 14-January-2020.

·      The reader of the current ASX Release is referred to the CCZ's first publication of the geological diagrams and associated information: "Drill program finalised to test 130m massive sulphide target at Arya prospect in Mt Oxide Pillar" released on the ASX by CCZ on the 1-July-2020.

·      The reader of the current ASX Release is referred to the CCZ's first publication of the geological diagrams and associated information: (1) "Final targets completed for drilling campaigns at Arya and Big One Deposit" released on the ASX by CCZ on the 14-July-2020. (2) "Field analysis verifies high-grade copper with newly identified gold mineralisation at Big One" released on the ASX by CCZ on the 14-Sep-2020.

·      The SRK Independent Geologists Report released by CCZ on the ASX on 28-July-2020 contains further details on the 'Exploration done by other parties - Acknowledgment and appraisal of exploration by other parties' this report is formally titled "A Competent Persons Report on the Mineral Assets of Castillo Copper Limited" Prepared as part of the Castillo Copper Limited (ASX: CCZ, LSE: CCZ) LSE Prospectus, with the effective date of the 17-July-2020.

·      The Mt Oxide North project is located within the Mt Isa Inlier of western Queensland, a large, exposed section of Proterozoic (2.5 billion- to 540-million-year-old) crustal rocks. The inlier records a long history of tectonic evolution, now thought to be like that of the Broken Hill Block in western New South Wales.

·      The Mt Oxide project lies within the Mt Oxide Domain, straddling the Lawn Hill Platform and Leichhardt River Fault Trough. The geology of the tenement is principally comprised of rocks of the Surprise Creek and Quilalar Formations which include feldspathic quartzites, conglomerates, arkosic grits, shales, siltstones and minor dolomites and limestones.

·      The Project area is cut by a major fault zone, trending north- northeast - south- southwest across the permits. This fault is associated with major folding, forming several tight syncline- anticline structures along its length.

·      The Desktop studies commissioned by CCZ on the granted mineral tenures described four main styles of mineralisation account for most mineral resources within the rocks of the Mt Isa Province (after Withnall & Cranfield, 2013).

o  Sediment hosted silver-lead-zinc - occurs mainly within fine-grained sedimentary rocks of the Isa Super basin within the Western Fold Belt. Deposits include Black Star (Mount Isa Pb-Zn), Century, George Fisher North, George Fisher South (Hilton) and Lady Loretta deposits.

o  Brecciated sediment hosted copper - occurs dominantly within the Leichhardt, Calvert and Isa Super basin of the Western Fold Belt, hosted in brecciated dolomitic, carbonaceous and pyritic sediments or brecciated rocks proximal to major fault/shear zones. Includes the Mount Isa copper orebodies and the Esperanza/Mammoth mineralisation.

o  Iron-oxide-copper-gold ("IOCG") - predominantly chalcopyrite-pyrite magnetite/hematite mineralisation within high grade metamorphic rocks of the Eastern Fold Belt. Deposits of this style include Ernest Henry, Osborne, and Selwyn; and

o  Broken Hill type silver-lead-zinc - occur within the high-grade metamorphic rocks of the Eastern Fold Belt. Cannington is the major example, but several smaller currently sub-economic deposits are known.

·      Gold is primarily found associated with copper within the IOCG deposits of the Eastern Fold Belt. However, a significant exception is noted at Tick Hill where high grade gold mineralisation was produced, between 1991 and 1995 by Carpentaria Gold Pty Ltd, some 700 000 tonnes of ore was mined at an average grade of 22.5 g/t Au, producing 15 900 kg Au. The Tick Hill deposit style is poorly understood (Withnall & Cranfield, 2013).

·      Rom Resources had noted in a series of recent reports for CCZ on the granted tenures, that cover the known mineralisation styles including:

o  Stratabound copper mineralisation within ferruginous sandstones and siltstones of the Surprise Creek Formation.

o  Disseminated copper associated with trachyte dykes.

o  Copper-rich iron stones (possible IOCG) in E-W fault zones; and

o  possible Mississippi Valley Type ("MVT") stockwork sulphide mineralisation carrying anomalous copper-lead-zinc and silver.

·      The Mt Oxide and Mt Gordon occurrences are thought to be breccia and replacement zones with interconnecting faults. The Mt Gordon/Mammoth deposit is hosted by brittle quartzites, and Esperanza by carbonaceous shales. Mineralisation has been related to the Isan Orogeny (1,590 - 1,500 Ma).

·      Mineralisation at all deposits is primarily chalcopyrite-pyrite-chalcocite, typically as massive sulphide within breccias.

·      At the Big One prospect, West Australian Metals NL described the mineralisation as (as sourced from the document "West Australian Metals NL, 1994. Drill Programme at the "Big One" Copper Deposit, North Queensland for West Australian Metals NL."):

o  The targeted lode / mineralised dyke is observable on the surface. The mineralisation targeted in the 1993 drilling programmed is a supergene copper mineralisation that includes malachite, azurite, cuprite, and tenorite, all associated with a NE trending fault (062^o to 242^o) that is intruded by a porphyry dyke.

o  The mineralised porphyry dyke is vertical to near vertical (85^o), with the 'true width' dimensions reaching up to 7m at surface.

o  At least 600m in strike length, with strong Malachite staining observed along the entire strike length, with historical open pits having targeted approximately 200m of this strike. Exact depth of mining below the original ground surface is not clear in the historical documents, given the pits are not battered it is anticipated that excavations have reached 5m to 10m beneath the original ground surface.

o  Associated with the porphyry dyke are zones of fractured and/or sheared rock, the siltstones are described as brecciated, and sandstones around the shear as carbonaceous.

o  The known mineralisation from the exploration activities to date had identified shallow supergene mineralisation, with a few drillholes targeting deeper mineralisation in and around the 200m of strike historical open

o  A strongly altered hanging wall that contained malachite and cuprite nodules. Chalcocite mineralization has been identified but it is unclear on the prevalence of the Chalcocite; and

o  The mineralisation was amenable to high grade open pit mining methods of the oxide mineralization (as indicated by numerous historical open pit shallow workings into the shear zone).

o  Thermal Gold Auroele mineralisation is a potential model due to the high silica alteration in thermal aureole with contact of A-Type Weberra Granite - related to the Au mineralisation; and/or

o  IOCG mineralisation related to chloride rich fluids

·      A selection of publicly available QDEX documents / historical exploration reports have been reviewed, refer to Section 2, sub-section "Further Work" for both actions in progress and proposed future actions.

·      The SRK Independent Geologists Report released by CCZ on the ASX on 28-July-2020 contains further details on the 'Geology - Deposit type, geological setting and style of mineralisation': this report is formally titled "A Competent Persons Report on the Mineral Assets of Castillo Copper Limited" Prepared as part of the Castillo Copper Limited (ASX: CCZ, LSE: CCZ) LSE Prospectus, with the effective date of the 17-July-2020.

·      For CCZ's current drilling program. This information has been recorded during the drilling and will be checked and verified at the conclusion of the current program.

·      Only 4 of 13 drillholes' assay has been completed on CCZ's current drilling program.

·      For historical drilling, Independent Laboratory Assay results for the 24 rock chip samples from the Big One Deposit were averaged if more than one reading or determination was given. There was no cutting of high-grade copper results as they are directly relatable to high grade mineralisation styles readily visible in the relevant samples. There was no cut-off grades factored into any assay results.

·      Rock chip samples were taken at areas of interest from observed mineralisation along the line of lode of the mineralised dyke, secondary structures and surrounding spoil heaps.

·      8 rock chip samples collected from rock faces and/or outcrops.

·      16 rock chip samples collected from stockpiles, shaft waste piles, and/or boulders of rock onsite.

·      The reader of the current ASX Release is referred to the CCZ's first publication of the geological diagrams and associated information: (1) "Final targets completed for drilling campaigns at Arya and Big One Deposit" released on the ASX by CCZ on the 14-July-2020. (2) "Field analysis verifies high-grade copper with newly identified gold mineralisation at Big One" released on the ASX by CCZ on the 14-Sep-2020.

·      This part will be done once CCZ's current drilling program is completed and all samples have been assayed and verified.

·      Appropriate diagrams are presented in the body and the Appendices of the current ASX Release. Where scales are absent from the diagram, grids have been included and clearly labelled to act as a scale for distance.

·      Maps and Plans presented in the current ASX Release are in MGA94 Zone 54, Eastings (mN), and Northing (mN), unless clearly labelled otherwise.

·      This part will be done once CCZ's current drilling program is completed and all samples have been assayed and verified.

·      Appropriate diagrams are presented in the body and the Appendices of the current ASX Release. Where scales are absent from the diagram, grids have been included and clearly labelled to act as a scale for distance.

·      Rock chip samples were taken at areas of interest from observed mineralisation along the line of lode of the mineralised dyke, secondary structures and surrounding spoil heaps.

·      8 rock chip samples collected from rock faces and/or outcrops. A statistical summary of the rock chip sample assay results is presented below:

·      16 rock chip samples collected from stockpiles, shaft waste piles, and/or boulders of rock onsite. A statistical summary of the 16-rock chip sample assay results are presented below:

·      No other ground or airborne geophysical surveys have been undertaken to date. Bulk density testing is yet to be carried out.

·      'Further work' is described within the body of the ASX Release.