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Altamira Gold Confirms That the Maria Bonita Discovery Is a Porphyry Gold Deposit

By: Newsfile

Vancouver, British Columbia--(Newsfile Corp. - June 19, 2024) - Altamira Gold Corp. (TSXV: ALTA) (FSE: T6UP) (OTC Pink: EQTRF), ("Altamira" or the "Company") is pleased to announce various further initiatives to explore the Cajueiro district in the light of the identification of porphyry hosted gold mineralization at the Maria Bonita discovery.


  • Field review of the drill core from the Maria Bonita discovery by renowned expert consultant, Dr R. Sillitoe has confirmed the porphyry origin of the mineralization. "Maria Bonita is undoubtedly a porphyry gold deposit as shown by the control of quartz veinlet intensity and gold grade as well as the A-type character of the quartz veinlets"
  • Dr Sillitoe also notes that "Porphyry systems commonly occur as clusters or alignments so additional examples might be anticipated in the general vicinity of Maria Bonita"
  • Initial diamond drilling previously reported at Maria Bonita has included the following mineralized intercepts showing the consistency of gold mineralization over wide intervals within the quartz porphyry: 146m @ 1.0g/t gold in MBA029; 50m @ 1.4g/t gold in MBA003; 55m @ 1 g/t gold in MBA 002; 50m @ 1 g/t gold in MBA001 and 53m @ 0.7g/t gold in MBA 022
  • The Company has retained expert consultants A.C.A. Howe (UK) and GeophysicsOne (Canada) to undertake interpretations using satellite imagery and proprietary aeromagnetic and radiometric surveys over the Cajueiro district to support the search for additional porphyry bodies

CEO Mike Bennett commented; "Following the receipt of recent drill results at Maria Bonita, we have moved swiftly to further our understanding of the potential of the Cajueiro district, by engaging highly regarded industry specialist consultants. The attribution of a porphyry gold style to the mineralization at Maria Bonita is a very significant development for the company as it is the first discovery of this type in Brazil. This realization provides a framework within which to interpret the current drill results, allows us to better vector further drilling and also opens up new search areas for mineralized intrusive bodies in the Cajueiro district."


The Cajueiro project is located approximately 75km NW of the town of Alta Floresta in the state of Mato Grosso (Figure 1) in central western Brazil and is easily accessible by road and has grid power and local water supply. Cajueiro is the most advanced of three key projects that Altamira controls in the region, the other two being Apiacas and Santa Helena (Figure1).

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Figure 1: Location of the Cajueiro, Apiacas and Santa Helena projects.

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The Cajueiro project has current NI 43-101 resources of 5.66Mt @ 1.02 g/t gold for a total of 185,000 oz in the Indicated Resource category and 12.66Mt @ 1.26 g/t gold for a total of 515,000 oz in the Inferred Resource category (estimated using a gold price of US$1,500/oz). The near-surface oxide portion of the Cajueiro resource contains an estimated 75,000 oz of gold.

Maria Bonita Target

Maria Bonita is located 7km west of the Cajueiro mineral resource and is easily accessible by road. Drilling to date has defined various intercepts of relatively uniform gold mineralization from surface associated with quartz veining and pervasive potassic alteration within a rhyolite intrusive. The best intercept to date is MBA029 which returned 146m @ 1g/t gold from 23m depth.

Initial metallurgical characterisation tests returned very positive gold recoveries of 88% (column leach of saprolite) and 90% (agitated leach in saprolite and fresh rock) on composite drill core samples.

The drill target was defined by a pronounced gold-in-soil anomaly measuring 250m by 300m with values over 400 ppb Au, located within a larger magnetic low feature. There is no outcrop in the immediate project area, however, recent mapping has identified similar rhyolite intrusive rocks one kilometre to the north-east of the discovery area. The intervening area has no outcrop, is largely covered by thick saprolite (8 to 16m depth) and thin alluvium which limits the effectiveness of soil sampling.

The drill core was reviewed on site with consultant Dr Richard Sillitoe, one of the leading global experts in porphyry mineralization, who confirmed an interpretation of the system as a porphyry gold deposit.

Dr Sillitoe concludes; "Maria Bonita is undoubtedly a porphyry gold deposit as shown by the control of quartz veinlet intensity and gold grade by the relative timing of the porphyry phases as well as the A-type character of the quartz veinlets". He further notes; "Maria Bonita is a highly unusual porphyry gold deposit…. [in that]... gold is part of a silicic (rhyolitic) system [with] weakly anomalous tin (20 ppm) and tungsten (11 ppm) contents and the presence of fluorite."

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Figure 2: Interpretative north-south cross-section of drill holes MBA022, and 015 looking west, showing two interpreted zones of early potassic altered and veined mineralized porphyry with later, lesser mineralized porphyry and a post-mineral barren porphyry phase. With the exception of minor late mafic dykes, all of the drill section is in rhyolite porphyry.

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Figure 3: Typical "A-type" quartz veins in "red-rock" altered early rhyolite porphyry

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The drill section shown in Figure 2 is based on geological and grade correlation with textural differentiation and contact relationships interpreted from drill core visible in drill core. The sub-cropping early porphyry phase carries bulk gold mineralization at around 1g/t Au associated with potassic alteration and quartz veining. The younger phases have significantly less quartz veining and a lower gold grade.

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Table 1: Summary of Phase 2 drill results at Maria Bonita

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Three-dimensional geological modelling is ongoing to identify untested extensions to the early porphyry carrying the most consistent gold mineralization.

The Maria Bonita intrusive suite consists of rhyolite porphyries with varying amounts and sizes of quartz and felspar phenocrysts. The early porphyry phase contains locally abundant quartz stockwork veining with typical "A-type" quartz veins (Figure 3). In some places later porphyry intrusive phases have unidirectional solidification textures (USTs) near their inferred upper contacts which can be used to interpret age relationships.

A post-mineral felspar porphyry forms two sets of dykes trending through the mineralized area, as defined by drilling. A similar felspar porphyry has been mapped approximately 1km to the north-east of the centre of the mineralized zone, suggesting a potential continuation of the intrusive system in that direction. A significant soil anomaly associated with an alluvial dispersion train is located along strike to the south west at the Novo Sonho target (Figure 4).

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Figure 4: Local setting of the Maria Bonita gold porphyry showing the mapped post mineral porphyry to the north east of the drilled area. Prior soil sampling has defined the Novo Sonho target to the south west of the gold porphyry and garimpo alluvial workings suggest that a SW-NE corridor of at least 5km, centred on the Maria Bonita porphyry is shedding gold into the south draining streams.

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Dr Sillitoe notes; "Porphyry systems commonly occur as clusters or alignments so additional examples might be anticipated in the general vicinity of Maria Bonita. The most likely location would be along strike of the currently defined system, to either the east or west."

Outcrop is very poor over much of the corridor of interest (Figure 4) and soil sampling results to date may be negatively impacted by transported alluvial cover. Based on a porphyry model, re-interpretation of relevant structural trends has been commissioned from A.C.A. Howe (UK) using available satellite imagery. This study will focus on both the direct extensions of the Maria Bonita intrusive suite and the potential for locating further intrusive centres within the larger Cajueiro exploration title.

Re-interpretation of proprietary regional fixed-wing aeromagnetic and radiometric data has also been commissioned from GeophysicsOne (Canada). These two new expert inputs will be integrated with Company regional geological mapping data to generate new targets for ground follow-up, using soil sampling and drone magnetics, to fully evaluate the porphyry-type potential.

Qualified Person

Guillermo Hughes, FAIG and M AusIMM., a consultant to the Company as well as a Qualified Person as defined by National Instrument 43-101, supervised 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 and copper projects within western central Brazil. The Company holds 6 projects comprising approximately 190,000 hectares, within the prolific Juruena gold belt which historically produced an estimated 7 to 10Moz of placer gold. The Company's advanced Cajueiro project has NI 43-101 resources of 5.66Mt @ 1.02 g/t gold for a total of 185,000 oz in the Indicated Resource category and 12.66Mt @ 1.26 g/t gold for a total of 515,000oz in the Inferred Resource category.

On Behalf of the Board of Directors,


"Michael Bennett"

Michael Bennett
President & CEO

Tel: 604.676.5660

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 with respect to the extension of the Warrants. 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.


Gold analysis has been conducted by SGS method FAA505 (fire assay of 50g charge), with higher grade samples checked by FAA525. Analytical quality is monitored by certified references and blanks. 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. Drill holes results are quoted as down-hole length weighted intersections.

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