Announcement PDF 16 April 2026 ACTIVITIES REPORT March 2026 Quarter HIGHLIGHTS • Murchison Gold District consolidation establishes dominant Western Australia footprint. Castle acquired 100% of Meekasan Pty Ltd while retaining 100% ownership of the Polelle and Wanganui Gold Projects, securing a contiguous ~184 km² greenstone landholding in the prolific Meekatharra gold district. The combined tenure is immediately adjacent to Westgold Resources' 1.5Moz+ Paddy's Flat operation and near Great Boulder Resources’ Side Well and Mulga Bill deposits, positioning the Company within an infrastructure rich, highly endowed proven gold corridor. With strong regional activity and a favourable gold price environment, Castle is advancing systematic exploration across the consolidated Meeka South Gold Project, targeting multiple high impact, drill ready opportunities defined through geochemistry and reprocessed aeromagnetic data. • Côte d’Ivoire portfolio advancing toward drill ready targets. Castle’s ~1,842 km² landholding across the Côte d’Ivoire–Ghana border includes the granted Ebony permit and six permits under application, with further approvals anticipated in the near term. Systematic soil geochemistry programs, combined with structural interpretation and aeromagnetic analysis, are progressing to define high priority targets across prospective Birimian greenstone belts. • Managing Director appointment drives execution across both jurisdictions. Steve Zaninovich assumed the role of full time Managing Director, transitioning from Non- Executive Chairman. The appointment, effective 1 March 2026, provides dedicated operational leadership and strategic execution capability as Castle advances its expanding gold portfolio across Côte d'Ivoire and the Western Australian goldfields. • Andrew Grove transitioned toNon-Executive Chairman,bringing over 30 years of mining industry experience and extensive West African operational credentials. • WestAfrican platform strengthened with enhanced leadership and operational focus. Following the Company's strategic pivot toward dual platform discovery growth, Mohamed Niarétransitioned fromNon-ExecutiveDirectortodedicated In-Country Project and Business Development Manager for Côte d'Ivoire operations, ensuring continued on ground leadership, stakeholder engagement and advancement of Castle's West African portfolio. This operational realignment reinforces Castle's commitment to accelerating exploration in the Côte d'Ivoire. • Cash. Cash as of 31 March 2026 was A$2.25 million. Castle Minerals Limited (“Castle”, “the Company”) (ASX:CDT) is pleased to provide an update on the quarter ending 31 March 2026. 2 CÔTE D’IVOIRE PROJECTS Ebony Permit (PR0965) – Regionalsoil sampling program & permitting progression During the quarter, Castle continued to progress the Ebony soil sampling program launched in Q4 2025 on the granted 343.1 km² permit, with further activities subject to finalisation of community approvals for ground access. An agreement with community leaders is close to being ratified, with high confidence that sampling works will resume shortly. The 981 sample regional soil geochemistry campaign (800 m x 100 m grids) targeting two prospective Birimian zones is planned to generate a robust geochemical baseline to characterise the mineralisation potential across the project. Results are expected to refine anomaly definitions and inform prioritisation of follow up infill sampling, possible trenching and first pass drilling programs. Across the broader seven permit (~1,842 km²) Côte d'Ivoire–Ghana border package acquired through Castle's 100% acquisition of Mineralis Ltd (with the right to earn up to 90% in each permit), the Company advanced permitting and tenure consolidation efforts. The Ebony permit (PR0965) has been granted, with six additional permits remaining under application. Recent engagement with the Côte d'Ivoire mining department indicates that approvals for a further two licences are anticipated early in the next quarter. This is expected to include the southern permits (~236 km²) located along the extension of the Bibiani–Chirano belt, positioning the Company to capitalise on the fertile Birimian greenstone geology that hosts numerous multi-million ounce gold mines across the West African region. The northern permit group (~1,606 km²) is centred approximately 25 km south of Endeavour Mining's Tanda-Iguela (Assafou) discovery, an area with known gold occurrences but limited systematic exploration. The Company is focused on expediting permitting timelines and advancing integrated exploration targeting using soil geochemistry, structural interpretation and aeromagnetic data to define high priority, drill ready targets across the portfolio. Figure 1: Proposed soil sampling areas (800m x 100m grids) on the granted Ebony permit (PR0965) WESTERN AUSTRALIA PROJECTS Polelle and Wanganui Gold Projects On 27 January 2026, Castle announced it has retained 100% ownership of the Polelle and Wanganui Gold Projects, located in the prolific Meekatharra goldfields of Western Australia. Castle and Great Boulder Resources (ASX:GBR) previously entered into an agreement granting GBR the option to earn up to a 75% interest in the projects, which was later extended. The option expired on 30 November 2025 (refer GBR ASX announcement of 20 January 2025). With GBR prioritising resource growth at its nearby ~1Moz Side Well Gold Project in Meekatharra, limited work was undertaken across the Polelle and Wanganui tenure. In the context of strong regional activity and a robust gold price environment, Castle elected not to extend the option and instead retain full ownership to unlock the value of these highly prospective assets. As a result, Castle is now well positioned to advance exploration across the Polelle and Wanganui Gold Projects, with an internal technical review underway to prioritise near term, high impact exploration opportunities. Meeka South Gold Project – Murchison District consolidation On 3 March 2026, Castle announced the execution of a binding share purchase agreement to acquire 100% of private company Meekasan Pty Ltd, securing 68 km² of highly prospective, contiguous greenstone tenure in the prolific Meekatharra gold district. The transaction consolidates Castle's position as a dominant junior company landholder in the region, establishing a ~184 km² strategic footprint (Figure 3) through integration with the Company's Polelle (98 km²) and Wanganui (18 km²) projects. TheMeekasan ground is immediately adjacent toWestgold Resources' Paddy'sFlat operation (historic production 1.5Moz+) and Great Boulder Resources' Mulga Bill project (568 koz @ 2.7g/t Au), positioning Castle within an established high grade gold corridor (Figure 3). The tenure spans more than 30 km of prospective greenstone strike with only shallow, wide spaced historical drilling to date, highlighting considerable upside potential. Historical exploration highlights at Meekasan include: 23 soil and stream sediment assays greater than 50 ppb Au (peak 763 ppb); undrilled magnetic anomalies with geophysical signatures mirroring the geological setting at nearby Paddy's Flat; and favourable greenstone assemblages (volcaniclastics, ultramafic and mafic units) intersected by WNW-ESE cross- cutting structures. Historical drilling has been limited to 163 shallow RAB/AC holes (average depth 32 m, maximum 69 m), underscoring the exploration potential (refer Castle ASX announcement of 3 March 2026) . Wanganui historical RC drilling has delivered shallow, high-grade intercepts including 3m @ 18.66g/t Au from 62m, 8m @ 4.10g/t Au from 66m, and 10m @ 3.34g/t Au from 56m, demonstrating the mineralisation potential across the consolidated Meeka South Gold Project (refer Castle ASX announcement of 19 August 2020). Forward work plan. The primary focus will be a tenement wide soil geochemistry program to fully characterise the geochemical signature and mineralisation potential of the Meeka South Gold Project. In parallel, priority targets identified from reprocessed magnetic datasets will be systematically field checked, with air core or RC drilling undertaken where field observations support the geophysical interpretation. At Wanganui, the Company will conduct 4 a review of the historical drill data with potential to accelerate a RC drill program to test the extension potential across the permit area. This staged exploration approach is designed to rapidly generate drill ready targets and support efficient capital deployment across the expanded landholding. Meekasan Pty Ltd Acquisition Terms: The Share Purchase Agreement is subject to customary conditions precedent, including completion of due diligence, receipt of required shareholder and regulatory approvals, execution of consultancy agreements with key Meekasan representatives (minimum 12-month period post-settlement) and granting of all tenure. Consideration comprises a non-refundable $15,000 exclusivity fee (60-day period), $150,000 cash at completion (cost reimbursement), 3,750,000 fully paid ordinary shares at settlement and a further 3,750,000 fully paid ordinary shares 12 months following settlement. KPALI AND KANDIA GOLD PROJECTS, GHANA During the quarter, Castle reviewed and assessed partial assay results from the Q4 2025 auger programs undertaken at Kandia (220 holes) and Bulenga (214 holes). The full analysis is expected to be complete in the next quarter, providing targets for a potential drill program. The Company continues to assess strategic options for this asset in line with its focus on gold exploration. KAMBALE GRAPHITE PROJECT, GHANA No work was undertaken at the 100% owned Kambale Graphite Project. Castle has previously advised that it is looking to monetise its interest, most likely through a partial or total sale or farm out arrangement. 5 Figure 2: Castle Meeka South Gold Project and other key operators in the region 6 Figure 3: Polelle, Wanganui and Meekasan Project Location CORPORATE Leadership realignment and Managing Director appointment Castle implemented a strategic leadership realignment during March 2026 to strengthen executive focus and governance oversight as the Company advances its dual platform discovery strategy in West Africa and Western Australia. Steve Zaninovich (Managing Director): Appointed full time effective 1 March 2026, transitioning from Non-Executive Chairman. Mr Zaninovich brings over 30 years of project development, operational experience, management and leadership experience across the resources sector, with significant expertise in West African gold exploration, development and M&A execution. His track record encompasses critical roles in greenfield discovery, project financing, jurisdictional navigation and stakeholder engagement across Côte d'Ivoire, Ghana and the broader West African region. Mr Zaninovich's combination of operational expertise, West African relationships and strategic M&A credentials positions him ideally to drive Castle's dual platform discovery strategy and accelerate execution across the Company's expanding Côte d'Ivoire and Western Australian gold portfolios. The appointment provides dedicated executive leadership and strategic execution capability as the Company scales exploration programs and evaluates next-stage growth pathways. 7 Andrew Grove (Non-Executive Chairman): Transitioned to governance oversight and strategic guidance role. Mr Grove brings over 30 years of exploration, development, operations and mine finance experience across West Africa and Australia, including prior Managing Director & CEO roles at Chesser Resources and Aura Energy, senior business development positions at Perseus Mining (Ghana and Côte d'Ivoire focus), and mine finance experience at Macquarie Bank. Mohamed Niaré (In-Country Project and Business Development Manager West Africa): Stepped down as Non-Executive Director to concentrate full time on advancing Castle's West African operations. Mr Niaré continues in his critical operational capacity, bringing local knowledge, community relationships management and on-ground experience essential to executing exploration and development programs in Côte d'Ivoire. This realignment ensures dedicated executive leadership for strategic M&A and operational delivery, strong Board governance and sustained in-country advancement of Castle's West African portfolio. FINANCIAL • As per ASX Listing Rule 5.3.2, there were no substantive mining production and development activities undertaken during the quarter. • As per ASX Listing Rule 5.3.1, a summary of the Company’s exploration activities for the quarter is contained herein, with exploration expenditure incurred during the period of A$346,000. • No payments were made to related parties during the quarter. • Castle Minerals remains well-funded with cash of A$2.25 million at 31 March 2026. For further information please contact: Steven Zaninovich Managing Director enquiries@castleminerals.com This announcement was authorised for release to the ASX by the Board of Castle Minerals Limited. - END – 8 ABOUT CASTLE MINERALS Castle Minerals Limited (ASX: CDT) is a gold explorer with extensive tenure positions in northern Ghana, eastern Côte d’Ivoire and Western Australia, some of the world’s premier gold producing regions. Withinitsportfolioin the UpperWest Region of Ghana,Castle holds the Kpali and KandiaGold Projects. The Company is contracted to earn interests in seven permits (one granted, six in application) along the Côte d’Ivoire – Ghana border. All projects are located on fertile Birimian greenstone belts, host to numerous multi-million ounce gold mines across Ghana, Côte d’Ivoire and the broader West African region. In Western Australia, Castle has established a dominant, contiguous ~184km2 landholding in the Murchison Gold District providing exposure to a proven gold province hosting multiple operating and past-producing mines. The Company’s Meeka South Gold Project boasts a strong infrastructure advantage located proximal to the Bluebird Gold ProcessingMill (Westgold) and near Meeka Metals’ Murchison Gold Project, with geology comparable to established regional producers. 9 PREVIOUSLY REPORTED INFORMATION RELATING TO THIS QUARTERLY REPORT Further information can be found in the releases referenced in this Report and/or in releases lodged by the Company with the ASX, including the following: Headline Date Castle retains Polelle and Wanganui Gold Projects in WA 27 January 2026 Castle Expands Murchison Gold Footprint & Board Changes 3 March 2026 SCHEDULE OF CASTLE MINERAL LICENCES (AS AT DATE OF THIS REPORT) Licence and Name Interest at beginning of Quarter Acquired / (Disposed) during the Quarter Interest at end of Quarter WESTERN AUSTRALIA Meeka South Gold Project - Meekatharra EL51/1703 - Wanganui 100% 100% EL51/1843 - Polelle 100% 100% PL51/3190 – 3198 - Polelle North 100% 100% GHANA 1 Kambale Graphite Limited (Graphite) (100% owned) PL 10/47 - Kambale 100% 100% Carlie Mining Limited (Gold)(100% owned) 2, 3 RL 10/52 - Jewoyeli Conversion Application Conversion Application RL 10/13 - Wa 100% 100% PL 10/26 - Degbiwu 100% 100% PL 10/23 - Bulenga 100% 100% PL 10/25 - Charingu Conversion Application Conversion Application PLA 10/13 - Kandia Conversion Application Conversion Application PL 10/24 - Baayiri Conversion Application Conversion Application RL 8/27 - Gbiniyiri Conversion Application Conversion Application RL 8/31 – Jumo Conversion Application Conversion Application CÔTE D’IVOIRE 4 Mineralis Limited (Right to earn up to 90%) PR0965 - Ebony 0% 0% PR0961 Application Application 0731DMICM15/04/2024 Application Application 0732DMICM15/04/2024 Application Application 0827DMICM29/04/2024 Application Application 0733DMICM15/04/2024 Application Application 0647DMICM27/03/2024 Application Application 1 The Government of Ghana has the right to a 10% free carried interest in all licences and is entitled to a 5% Gross Royalty on production. 2 Carlie Mining Limited has lodged applications to convert an acquired Retention Licence into several smaller area Prospecting Licences, for extensions to the terms of certain licences and/or renewals under the Ghana Mining Act. It has 10 paid and received all amounts invoiced by Ghana MINCOM to effect these. In most cases the Company is awaiting receipt of documentary confirmation of these licences in the form of contracts duly executed by the responsible Minister. There is uncertainty as to whether or not additional official imposts will be required to be paid to have Carlie’s licences fully verified and executed by the Minister. 3. Julie West Royalty. Castle’s wholly owned Ghanaian subsidiary, Carlie Mining Limited, holds a contractual right to a 4% gross royalty on all gold mined and sold from the Julie West prospecting licence owned by Phoenix Resources Limited, a wholly owned Ghanaian subsidiary of Azumah Resources Limited. The Julie West licence is located close to several of Castle’sWa Gold Project licencesinGhana’sUpper West Region.Combined Mineral Resourcesat Jule West of ~100,000oz at ~3.8g/t Au are part of Azumah’s Black Volta Gold Project which it is understood, subject to financing, is earmarked for development. There is no certainty if and when a royalty might be paid and what the impact of extensive illegal artisanal mining on the licence may have on its quantum. 4. The Government of Côte d’Ivoire is entitled to a 10% free carried interest in mining licences and a sliding scale royalty on gold production, typically ranging from approximately 3% to 5% depending on the gold price. STATEMENTS Historical Exploration Results - Competent Person’s Compliance Statement The Company is not aware of any new information or data that materially affects the information included in the relevant historical market announcements referenced herein. Cautionary Statement All of Castle’s projects in Australia are considered grassroots or at a relatively early stage of exploration. There has been insufficient exploration to define a Mineral Resource. No Competent Person has done sufficient work in accordance with JORC Code 2012 to determine conclusively or to estimate in what quantities gold or other minerals are present. It is possible that, following further evaluation and/or exploration work, confidence in the information used to identify areas of interest may be reduced when reported under the JORC Code (2012). Forward Looking Statement Statements regarding Castle’s plans, forecasts and projections with respect to its mineral properties and programmes are forward looking statements. There can be no assurance that Castle’s plans for the development of its mineral properties will proceed. There can be no assurance that Castle will be able to confirm the presence of Mineral Resources or Ore Reserves, that any mineralisation will proveto be economic or that a mine will be successfully developed on any of Castle’s mineral properties. The performance of Castle may be influenced by factors outside the control of the Company, its Directors, staff or contractors. Rule 5.5 ASX Listing Rules Appendix 5B (17/07/20) Page 1 + See chapter 19 of the ASX Listing Rules for defined terms. Appendix 5B Mining exploration entity or oil and gas exploration entity quarterly cash flow report Name of entity Castle Minerals Limited ABN Quarter ended (“current quarter”) 83 116 095 802 31 March 2026 Consolidated statement of cash flows Current quarter $A’000 Year to date (9 months) $A’000 1. Cash flows from operating activities - - 1.1 Receipts from customers 1.2 Payments for (346) (1,776) (a) exploration & evaluation (b) development - - (c) production - - (d) staff costs (113) (240) (e) administration and corporate costs (256) (917) 1.3 Dividends received (see note 3) - - 1.4 Interest received 4 8 1.5 Interest and other costs of finance paid - - 1.6 Income taxes paid - - 1.7 Government grants and tax incentives - - 1.8 Other (provide details if material) - - 1.9 Net cash from / (used in) operating activities (711) (2,925) 2. Cash flows from investing activities - (100) 2.1 Payments to acquire or for: (a) entities (b) tenements - - (c) property, plant and equipment - - (d) exploration & evaluation - - (e) investments - - (f) other non-current assets - - Appendix 5B Mining exploration entity or oil and gas exploration entity quarterly cash flow report ASX Listing Rules Appendix 5B (17/07/20) Page 2 + See chapter 19 of the ASX Listing Rules for defined terms. Consolidated statement of cash flows Current quarter $A’000 Year to date (9 months) $A’000 2.2 Proceeds from the disposal of: - - (a) entities (b) tenements - - (c) property, plant and equipment - - (d) investments - - (e) other non-current assets - - 2.3 Cash flows from loans to other entities - - 2.4 Dividends received (see note 3) - - 2.5 Other (provide details if material) Transaction costs associated with investment in entities - (35) 2.6 Net cash from / (used in) investing activities - (135) 3. Cash flows from financing activities - 3,030 3.1 Proceeds from issues of equity securities (excluding convertible debt securities) 3.2 Proceeds from issue of convertible debt securities - - 3.3 Proceeds from exercise of options - - 3.4 Transaction costs related to issues of equity securities or convertible debt securities - (211) 3.5 Proceeds from borrowings - - 3.6 Repayment of borrowings - - 3.7 Transaction costs related to loans and borrowings - - 3.8 Dividends paid - - 3.9 Other (Principal elements of lease payments) - - 3.10 Net cash from / (used in) financing activities - 2,819 4. Net increase / (decrease) in cash and cash equivalents for the period 4.1 Cash and cash equivalents at beginning of period 2,963 2,500 4.2 Net cash from / (used in) operating activities (item 1.9 above) (711) (2,925) 4.3 Net cash from / (used in) investing activities (item 2.6 above) - (135) Appendix 5B Mining exploration entity or oil and gas exploration entity quarterly cash flow report ASX Listing Rules Appendix 5B (17/07/20) Page 3 + See chapter 19 of the ASX Listing Rules for defined terms. Consolidated statement of cash flows Current quarter $A’000 Year to date (9 months) $A’000 4.4 Net cash from / (used in) financing activities (item 3.10 above) - 2,819 4.5 Effect of movement in exchange rates on cash held (2) (9) 4.6 Cash and cash equivalents at end of period 2,250 2,250 5. Reconciliation of cash and cash equivalents at the end of the quarter (as shown in the consolidated statement of cash flows) to the related items in the accounts Current quarter $A’000 Previous quarter $A’000 5.1 Bank balances 2,250 2,963 5.2 Call deposits - - 5.3 Bank overdrafts - - 5.4 Other (provide details) - - 5.5 Cash and cash equivalents at end of quarter (should equal item 4.6 above) 2,250 2,963 6. Payments to related parties of the entity and their associates Current quarter $A'000 6.1 Aggregate amount of payments to related parties and their associates included in item 1 - 6.2 Aggregate amount of payments to related parties and their associates included in item 2 - Note: if any amounts are shown in items 6.1 or 6.2, your quarterly activity report must include a description of, and an explanation for, such payments. Appendix 5B Mining exploration entity or oil and gas exploration entity quarterly cash flow report ASX Listing Rules Appendix 5B (17/07/20) Page 4 + See chapter 19 of the ASX Listing Rules for defined terms. 7. Financing facilities Note: the term “facility’ includes all forms of financing arrangements available to the entity. Add notes as necessary for an understanding of the sources of finance available to the entity. Total facility amount at quarter end $A’000 Amount drawn at quarter end $A’000 7.1 Loan facilities - - 7.2 Credit standby arrangements - - 7.3 Other (please specify) - - 7.4 Total financing facilities - - 7.5 Unused financing facilities available at quarter end - 7.6 Include in the box below a description of each facility above, including the lender, interest rate, maturity date and whether it is secured or unsecured. If any additional financing facilities have been entered into or are proposed to be entered into after quarter end, include a note providing details of those facilities as well. n/a 8. Estimated cash available for future operating activities $A’000 8.1 Net cash from / (used in) operating activities (item 1.9) (711) 8.2 (Payments for exploration & evaluation classified as investing activities) (item 2.1(d)) - 8.3 Total relevant outgoings (item 8.1 + item 8.2) (711) 8.4 Cash and cash equivalents at quarter end (item 4.6) 2,250 8.5 Unused finance facilities available at quarter end (item 7.5) - 8.6 Total available funding (item 8.4 + item 8.5) 2,250 8.7 Estimated quarters of funding available (item 8.6 divided by item 8.3) 3.17 Note: if the entity has reported positive relevant outgoings (ie a net cash inflow) in item 8.3, answer item 8.7 as “N/A”. Otherwise, a figure for the estimated quarters of funding available must be included in item 8.7. 8.8 If item 8.7 is less than 2 quarters, please provide answers to the following questions: 8.8.1 Does the entity expect that it will continue to have the current level of net operating cash flows for the time being and, if not, why not? Answer: n/a 8.8.2 Has the entity taken any steps, or does it propose to take any steps, to raise further cash to fund its operations and, if so, what are those steps and how likely does it believe that they will be successful? Answer: n/a 8.8.3 Does the entity expect to be able to continue its operations and to meet its business objectives and, if so, on what basis? Answer: n/a Note: where item 8.7 is less than 2 quarters, all of questions 8.8.1, 8.8.2 and 8.8.3 above must be answered. Appendix 5B Mining exploration entity or oil and gas exploration entity quarterly cash flow report ASX Listing Rules Appendix 5B (17/07/20) Page 5 + See chapter 19 of the ASX Listing Rules for defined terms. Compliance statement 1 This statement has been prepared in accordance with accounting standards and policies which comply with Listing Rule 19.11A. 2 This statement gives a true and fair view of the matters disclosed. Date: 16 April 2026 Authorised by: Board of Directors (Name of body or officer authorising release – see note 4) Notes 1. This quarterly cash flow report and the accompanying activity report provide a basis for informing the market about the entity’s activities for the past quarter, how they have been financed and the effect this has had on its cash position. An entity that wishes to disclose additional information over and above the minimum required under the Listing Rules is encouraged to do so. 2. If this quarterly cash flow report has been prepared in accordance with Australian Accounting Standards, the definitions in, and provisions of, AASB 6: Exploration for and Evaluation of Mineral Resources and AASB 107: Statement of Cash Flows apply to this report. If this quarterly cash flow report has been prepared in accordance with other accounting standards agreed by ASX pursuant to Listing Rule 19.11A, the corresponding equivalent standards apply to this report. 3. Dividends received may be classified either as cash flows from operating activities or cash flows from investing activities, depending on the accounting policy of the entity. 4. If this report has been authorised for release to the market by your board of directors, you can insert here: “By the board”. If it has been authorised for release to the market by a committee of your board of directors, you can insert here: “By the [name of board committee – eg Audit and Risk Committee]”. If it has been authorised for release to the market by a disclosure committee, you can insert here: “By the Disclosure Committee”. 5. If this report has been authorised for release to the market by your board of directors and you wish to hold yourself out as complying with recommendation 4.2 of the ASX Corporate Governance Council’s Corporate Governance Principles and Recommendations, the board should have received a declaration from its CEO and CFO that, in their opinion, the financial records of the entity have been properly maintained, that this report complies with the appropriate accounting standards and gives a true and fair view of the cash flows of the entity, and that their opinion has been formed on the basis of a sound system of risk management and internal control which is operating effectively.