Altamira Gold Discovers New Mineralized Porphyry Body at Maria Bonita West, Cajueiro Gold District, Brazil

About this update from Altamira Gold Corp

Vancouver, British Columbia--(Newsfile Corp. - August 25, 2026) - Altamira Gold Corp. (TSXV: ALTA) (FSE: T6UP) (OTCQB: EQTRF), (" Altamira " or the " Company ") is pleased to announce the results of four additional drill holes, MBA-040 to 043, which tested the western extension of the Maria Bonita gold porphyry system. Two of these drill holes returned wide intervals of gold mineralization, confirming the presence of a new mineralized early porphyry body, previously detected in hole MBA-036 (70.6m @ 0.5g/t gold); see press release dated May 12, 2026. Highlights: President & CEO Michael Bennett commented; "Our continued exploration drilling program over the western part of the Maria Bonita mineralized porphyry system is delivering highly encouraging results. We have now confirmed a new mineralized porphyry body at Maria Bonita West, with drill holes MBA-042 and MBA-043 delivering two of the widest coherent mineralized intersections encountered in our drilling to date. These positive results suggest that the Maria Bonita system extends further west than previously recognized with the mineralized body remaining open to the west and at depth. With our recently secured land access to the adjacent property, we are now in a strong position to continue drilling westward and evaluate the full potential of this growing mineralized system." CAJUEIRO DISTRICT The Cajueiro district is located approximately 75km NW of the town of Alta Floresta in the state of Mato Grosso (Figure 1) in central western Brazil. The project is easily accessible by road, lies on open farmland and has grid power and a local water supply. Cajueiro is the most advanced of the key projects that Altamira controls in the region (Figure 1). Figure 1: Location of Altamira Gold's projects in the Alta Floresta Belt. To view an enhanced version of this graphic, please visit: https://images.newsfilecorp.com/files/4500/311392_2926bf9384d3585d_001full.jpg The Cajueiro district consists of two independently estimated gold mineral resources at Cajueiro Central and Maria Bonita, plus a series of eight additional untested exploration targets within a radius of 8km of Cajueiro Central. The Cajueiro Central area has a current open pit resource1 of 5.66Mt @ 1.02 g/t gold containing 185,000 oz in the Indicated Resource category and 12.66Mt @ 1.26 g/t gold (515,000 oz) in the Inferred Resource category (estimated using a cut-off grade of 0.25g/t Au and a gold price of US$1,500/oz). The Maria Bonita open-pit resource consists of Indicated Resources of 24.19Mt @ 0.46g/t gold (357,800oz) and Inferred Resources of 25.64Mt @ 0.44g/t gold (362,400oz)2. These resources were calculated using a 0.2 g/t gold cut-off grade and a gold price of US$2,780/oz. These resources include near-surface saprolite Indicated Resources of 2.02Mt @ 0.59g/t gold (38,000oz) and Inferred Resources of 0.68Mt @ 0.40g/t gold (8,700oz). The Maria Bonita porphyry gold deposit forms part of a district-scale portfolio of prospects that are interpreted as having a similar geological origin (Figure 2). The Cajueiro area is characterized by a 15km stretch of former alluvial gold workings along the Teles Pires river. The source of some of this alluvial gold is related to a pronounced east-west corridor of gold anomalies in soils and rock chips and a set of sub-cropping intrusions extending east-west, implying the presence of a long-standing and deep-seated reactivated crustal structure. Figure 2: Cajueiro district mineral resources at Cajueiro Central and Maria Bonita (white labels) and prospects (blue labels with scout drilling, yellow labels not yet drilled). An alignment of six of the targets occur in close spatial association to a pronounced east-west fault corridor marked by later gabbroic dykes.  To view an enhanced version of this graphic, please visit: https://images.newsfilecorp.com/files/4500/311392_2926bf9384d3585d_002full.jpg Mara Bonita West Recent drilling including drill holes MBA-036 to MBA-043 (Table 1) focused on testing the western extension of the early porphyry system that hosts the strongest gold mineralization at Maria Bonita. A separate western body of early porphyry was discovered in MBA-036 (70.6m @ 0.5g/t gold) and mineralized quartz veining within the porphyry and extending into wall rock tuffs were intersected in MBA-037 (122m@ 0.5g/t gold). Subsequent drilling was directed at better delineating both the porphyry and veined zones in the surrounding tuff wall rocks. Recent trenching, drilling and geochemical studies have improved the Company's understanding of the relationship between Maria Bonita East and West. The two areas appear to be separated by a northeast-trending fault zone occupied by late, post-mineral dykes (Figure 3). The West porphyry is located to the west of this zone and has now been confirmed by MBA-042 and MBA-043 (Figure 4). Table 1: Coherent mineralized intercepts for MBA-042 and MBA-043 Holes MBA-042 and MBA-043 both intersected over 200m of continuous, relatively uniform gold grades in quartz veined early porphyry. The holes are adjacent and 100m apart, suggesting good continuity of mineralization between them. Both drill holes ended in mineralization, leaving the Maria Bonita West porphyry body open to the west and at depth. These intervals are inferred to connect with the deeper MBA-036 interval (70.6m @ 0.5g/t gold). Drill holes MBA-040 and MBA-041, completed in the tuff wall rock along the northern margin of the target, intersected, weakly mineralized, locally veined tuffs, and likely define the near-surface northern limit of the more strongly mineralized vein zones in tuff host rocks (Figure 3). However, the contact relationships between these host rocks and the mineralized intrusions at depth remain poorly constrained and require further drilling. Figure 3: Maria Bonita West interpreted solid geology from drilling. To view an enhanced version of this graphic, please visit: https://images.newsfilecorp.com/files/4500/311392_2926bf9384d3585d_003full.jpg The northwest-southeast section (Figure 4) demonstrates that the early porphyry remains open at depth and to the west. With the Company now having access to the adjacent farm, exploration can continue westward with shallow holes designed to map the extent of the porphyry near-surface. As this porphyry contains accessory pyrite, in contrast to the Maria Bonita Central body, trial induced polarization survey lines will be used to test whether the mineralization can be detected as a chargeability anomaly. Figure 4: Northwest-southeast drill section showing MBA-036, MBA-042 and MBA-043 outside the 2025 resource pit and confirming that the mineralized porphyry body remains open to the west and at depth. To view an enhanced version of this graphic, please visit: https://images.newsfilecorp.com/files/4500/311392_2926bf9384d3585d_004full.jpg Drilling has recently been concluded on hole MBA-046 with assay results pending for MBA-044 and 045. The Company plans to continue evaluating the westward extension of the Maria Bonita West porphyry through additional drilling. Soil sampling plus drone and ground geophysics will also be used to help define the extent of the open anomalies to the west and identify additional targets for follow-up exploration. Grant of Stock Options Altamira also announces that it has granted 8,050,000 stock options to directors, officers, employees, and consultants of the Company at an exercise price of C$0.20 per common share. The stock options are exercisable for five years and are subject to vesting over 12 months. The options are subject to the Company's Stock Option Plan. Qualified Person Fernando Benegas, FAusIMM, a consultant to the Company as well as a Qualified Person as defined by National Instrument 43-101, supervised and approved the preparation of the technical information in this news release. About Altamira Gold Corp. The Company is focused on the exploration and development of gold projects within western central Brazil, strategically advancing four projects spanning over 90,000 hectares within the prolific Juruena Gold Belt, an area that has historically yielded over 6 million ounces of placer gold3. The Company's advanced Cajueiro project contains two gold deposits. Ongoing exploration and fieldwork at Cajueiro indicate the presence of multiple hard rock gold occurrences, traceable from historical alluvial gold production, highlighting the region's exceptional gold endowment and potential scalability. With two independently established mineral resources, a highly prospective geological setting and a track record of significant discoveries, the Company is well-positioned to unlock further value across its extensive land package. 1 NI 43-101 Technical Report, Cajueiro Project, Mineral Resource Estimate: Global Resource Engineering, Denver Colorado USA, 10 th  October 2019; Authors K. Gunesch, PE; H. Samari, QP-MMSA; T. Harvey, QP-MMSA 2 NI43-101 Technical Report, Mineral Resource for the Maria Bonita Prospect: VMG Consultoria, Belo Horizonte, Minas Gerais, Brazil. 12 th June 2025; Author V. Myadzel 3 Juliani, C. et al; Gold in Paleoproterozoic (2.1 to 1.77 Ga) Continental Magmatic Arcs at the Tapajós and Juruena Mineral Provinces (Amazonian Craton, Brazil): A New Frontier for the Exploration of Epithermal-Porphyry and Related Deposits. Minerals 2021, 11, 714. https://doi.org/10.3390/min11070714 On Behalf of the Board of Directors, ALTAMIRA GOLD CORP. "Michael Bennett" Michael Bennett President & CEO Tel: +1 604.676.5661 [email protected] www.altamiragold.com Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release. The securities described herein have not been registered under the U.S. Securities Act or any state securities laws and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements under the U.S. Securities Act and any applicable state securities laws. Forward-looking Statements Certain information contained herein constitutes "forward-looking information" under Canadian securities legislation. Forward-looking information includes, but is not limited to, statements regarding the Company's planned exploration activities at Maria Bonita, including soil and stream-sediment sampling, geological mapping, geophysical interpretation, drill-target definition and future drilling; the timing and scope of such programs; the interpretation of geochemical and geophysical anomalies; the potential identification of primary gold sources and intrusion-related mineralization; the potential extension of the current Maria Bonita mineral resource to the west; and the Company's ability to obtain or maintain the necessary surface access, permits and regulatory approvals. Generally, forward-looking information can be identified by the use of forward-looking terminology such as "will", "intends" or variations of such words and phrases or statements that certain actions, events or results "will" occur. Forward-looking statements are based on the opinions and estimates of management as of the date such statements are made and they are subject to known and unknown risks, uncertainties and other factors that may cause the actual results to be materially different from those expressed or implied by such forward-looking statements or forward-looking information, including the receipt of all necessary regulatory approvals. Although management of the Company has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking statements or forward-looking information, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements and forward-looking information. The Company will not update any forward-looking statements or forward-looking information that is incorporated by reference herein, except as required by applicable securities laws. Quality Assurance/Quality Control Drill holes commence in HQ diameter (63.5mm) and proceed to the base of weathering where core diameter is reduced to NQ (47.6mm). Logging and sampling are completed at a secure Company facility located on site. Drill core is cut in half on site by a saw cut or slicer (in soft saprolite). Until dispatch, samples are stored under the supervision the Company's exploration office. The samples are couriered to the assay laboratory using a commercial contractor. Pulps are returned to the Company and archived. For all drilling, half core is submitted to SGS Geosol, a leading commercial laboratory in Brazil and analysed for gold by 50g fire assay, plus a suite of other elements by the ICP atomic absorption method, using standard laboratory procedures. Soil and rock chip samples follow the same analytical protocol. Quality control of drill hole assays follows normal industry procedures of inserting control samples randomly into the submitted batch, comprising field duplicates, independent reference samples and "blank" samples. Selected batches of sample pulps are periodically resubmitted to a third-party laboratory to check the main laboratory precision and accuracy. Drill holes results are quoted as down-hole length weighted intersections. True widths have not yet been determined. Additional information regarding the Company data verification processes is set out in the NI 43-101 Technical Report, Maria Bonita Prospect, June 2025 , which can be found on the Company's website. To view the source version of this press release, please visit https://www.newsfilecorp.com/release/311392

View stock analysis, news, and events for Altamira Gold Corp