Altamira Gold Announces Significant Increase in Mineral Resources at the Maria Bonita Porphyry Gold Deposit, Cajueiro District, Brazil
Original announcement by newsfile on
- Company
- Altamira Gold Corp.
- Ticker
- ALTA
- Exchange
- Unavailable
- Region
- Brazil
- Primary commodity
- Gold
- Secondary commodities
- None reported
- Document categories
- Resource update
- Extracted
- 2026-09-21 13:19:09 UTC
Analysis by Minestarters Atlas
Atlas analysis published:
Minestarters Atlas analysis
Summary
Altamira Gold has announced a significant update to the Maria Bonita porphyry gold resource in Brazil, reporting a 90% increase in total tonnage compared to the 2025 maiden estimate. The updated resource includes 25Mt of Indicated and 70Mt of Inferred resources at a 0.24 g/t gold cut-off, driven by successful step-out drilling.
Reasoning: The update shows massive scale expansion in both tonnage and contained gold, significantly de-risking the project's potential as a bulk-tonnage porphyry asset.
Positive factors
- Tonnage growth of 90% vs maiden estimate
- Contained gold growth of 82% vs maiden estimate
- Significant expansion in Inferred category (150% increase)
- High-grade sector growth at 0.5 g/t cut-off
- QA/QC disclosed with SGS Geosol and standard methods
- QP/CP sign-off by Volodymyr Myadzel and Fernando Benegas
Negative factors
- Apparent width only (true widths not yet determined)
Facts used in scoring: 4
Classification and evidence
Tonnage Growthpositive
Significant tonnage increase (≥15%) vs prior estimate with grade maintained or improved.
Why it applies: Total resource tonnage increased by 90% compared to the 2025 maiden estimate.
Evidence · text
“total resource tonnage increasing by 90%”
Contained Metal Growthpositive
True scale improvement — contained metal ounces/tonnes increased vs prior, accounting for both tonnage and grade changes.
Why it applies: Contained gold increased by 82% compared to the maiden estimate.
Evidence · text
“contained gold by 82%”
NI 43-101 Compliantpositive
Resource estimate prepared in compliance with NI 43-101 (Canada) — high reporting standard.
Why it applies: The resource estimate was prepared in accordance with NI 43-101 standards.
Evidence · text
“updated Mineral Resource Estimate ("MRE") for the Maria Bonita porphyry gold deposit”
QA/QC Disclosedpositive · Story-specific tag
Release includes QA/QC disclosure — certified lab, QP sign-off, or stated methods (blanks, standards, duplicates).
Why it applies: The release details laboratory (SGS Geosol), methods (fire assay, ICP), and QC protocols (blanks, standards, duplicates).
Evidence · text
“half core is submitted to SGS Geosol... inserting control samples randomly... field duplicates, independent reference samples and "blank" samples.”
Apparent Width Onlynegative · Story-specific tag
Interval given as downhole width with no true width or drill orientation — apparent width may overstate true thickness.
Why it applies: The document explicitly states that true widths have not yet been determined.
Evidence · text
“True widths have not yet been determined.”
Extracted facts
Stored fact records: 4. Some facts used in scoring do not have a stored record.
Resource Estimates (4)
indicatedCajueiro Project · goldTonnes: 25000000Grade: 0.5Grade Unit: g/tContained Metal: 403877Contained Unit: ozView all detailsHide details
Identity
- Project
- Cajueiro Project
- Commodity
- gold
- Region
- brazil
- Reported Region
- Brazil
- Ticker
- ALTA
Resource scope
- Estimate type
- resource
- Effective date
- 2026-09-16T00:00:00.000Z
- Reporting standards
- ni_43_101
- QP Signed
- Yes
- Qualified person names
- Volodymyr Myadzel, Fernando Benegas
- Resource group id
- resource:604caeb51faeff21bf6a
- Deposit or zone
- Maria Bonita
- Mining method
- open_pit
- Material type
- fresh
- Resource basis
- gross
Resource Data
- Category
- indicated
- Tonnes
- 25000000
- Grade
- 0.5
- Grade Unit
- g/t
- Contained Metal
- 403877
- Contained Unit
- oz
- Cutoff Grade
- 0.24
- Cutoff Unit
- g/t gold
Prior Estimate
- Resource Date
- 2026-09-16
Lab
- Laboratory
- SGS Geosol
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2026-09-21T00:00:00.000Z
Reasoning: Strong Indicated resource component for a porphyry deposit.
Positive factors
- Significant tonnage and grade maintenance
Evidence · text
“Indicated Resources of 25Mt @ 0.50g/t gold (403,877oz contained)”
Tags used in scoring
Indicated Resourcepositive
Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.
Why it applies: category is "indicated"
Cut-off Disclosedpositive
Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.
Why it applies: cutoff_grade is stated
QP/CP Signedpositive
Qualified Person (QP) or Competent Person (CP) named and signed off — a member of a recognized professional association (e.g., AusIMM, SME, AIG, P.Geo) with relevant experience.
Why it applies: qp_signed is true
NI 43-101 Compliantpositive
Resource estimate prepared in compliance with NI 43-101 (Canada) — high reporting standard.
Why it applies: reporting_standards includes ni_43_101
Resource Updateneutral
Revised estimate for an existing resource — compare to prior to assess progress.
Why it applies: the release compares against a previous estimate
inferredCajueiro Project · goldTonnes: 70000000Grade: 0.41Grade Unit: g/tContained Metal: 908477Contained Unit: ozView all detailsHide details
Identity
- Project
- Cajueiro Project
- Commodity
- gold
- Region
- brazil
- Reported Region
- Brazil
- Ticker
- ALTA
Resource scope
- Estimate type
- resource
- Effective date
- 2026-09-16T00:00:00.000Z
- Reporting standards
- ni_43_101
- QP Signed
- Yes
- Qualified person names
- Volodymyr Myadzel, Fernando Benegas
- Resource group id
- resource:0149a29c905cf4b05d87
- Deposit or zone
- Maria Bonita
- Mining method
- open_pit
- Material type
- fresh
- Resource basis
- gross
Resource Data
- Category
- inferred
- Tonnes
- 70000000
- Grade
- 0.41
- Grade Unit
- g/t
- Contained Metal
- 908477
- Contained Unit
- oz
- Cutoff Grade
- 0.24
- Cutoff Unit
- g/t gold
Prior Estimate
- Resource Date
- 2026-09-16
Lab
- Laboratory
- SGS Geosol
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2026-09-21T00:00:00.000Z
Reasoning: Large scale expansion of the resource footprint.
Positive factors
- 150% increase in contained ounces vs maiden
Evidence · text
“Inferred Resources of 70Mt @ 0.41g/t gold (908,477oz)”
Tags used in scoring
Inferred Resourcenegative
Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone.
Why it applies: category is "inferred"
Cut-off Disclosedpositive
Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.
Why it applies: cutoff_grade is stated
QP/CP Signedpositive
Qualified Person (QP) or Competent Person (CP) named and signed off — a member of a recognized professional association (e.g., AusIMM, SME, AIG, P.Geo) with relevant experience.
Why it applies: qp_signed is true
NI 43-101 Compliantpositive
Resource estimate prepared in compliance with NI 43-101 (Canada) — high reporting standard.
Why it applies: reporting_standards includes ni_43_101
Resource Updateneutral
Revised estimate for an existing resource — compare to prior to assess progress.
Why it applies: the release compares against a previous estimate
indicatedCajueiro Project · goldTonnes: 1490000Grade: 0.65Grade Unit: g/tContained Metal: 30899Contained Unit: ozView all detailsHide details
Identity
- Project
- Cajueiro Project
- Commodity
- gold
- Region
- brazil
- Reported Region
- Brazil
- Ticker
- ALTA
Resource scope
- Estimate type
- resource
- Effective date
- 2026-09-16T00:00:00.000Z
- Reporting standards
- ni_43_101
- QP Signed
- Yes
- Qualified person names
- Volodymyr Myadzel, Fernando Benegas
- Resource group id
- resource:07e667da8e42d6dee610
- Deposit or zone
- Maria Bonita
- Mining method
- open_pit
- Material type
- saprolite
- Resource basis
- gross
Resource Data
- Category
- indicated
- Tonnes
- 1490000
- Grade
- 0.65
- Grade Unit
- g/t
- Contained Metal
- 30899
- Contained Unit
- oz
- Cutoff Grade
- 0.24
- Cutoff Unit
- g/t gold
Prior Estimate
- Resource Date
- 2026-09-16
Lab
- Laboratory
- SGS Geosol
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2026-09-21T00:00:00.000Z
Reasoning: Provides high-grade near-surface component.
Positive factors
- Near-surface saprolite resource identified
Evidence · text
“saprolite Indicated resources of 1.49Mt @ 0.65g/t (30,899oz)”
Tags used in scoring
Indicated Resourcepositive
Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.
Why it applies: category is "indicated"
Cut-off Disclosedpositive
Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.
Why it applies: cutoff_grade is stated
QP/CP Signedpositive
Qualified Person (QP) or Competent Person (CP) named and signed off — a member of a recognized professional association (e.g., AusIMM, SME, AIG, P.Geo) with relevant experience.
Why it applies: qp_signed is true
NI 43-101 Compliantpositive
Resource estimate prepared in compliance with NI 43-101 (Canada) — high reporting standard.
Why it applies: reporting_standards includes ni_43_101
Resource Updateneutral
Revised estimate for an existing resource — compare to prior to assess progress.
Why it applies: the release compares against a previous estimate
inferredCajueiro Project · goldTonnes: 1420000Grade: 0.38Grade Unit: g/tContained Metal: 17172Contained Unit: ozView all detailsHide details
Identity
- Project
- Cajueiro Project
- Commodity
- gold
- Region
- brazil
- Reported Region
- Brazil
- Ticker
- ALTA
Resource scope
- Estimate type
- resource
- Effective date
- 2026-09-16T00:00:00.000Z
- Reporting standards
- ni_43_101
- QP Signed
- Yes
- Qualified person names
- Volodymyr Myadzel, Fernando Benegas
- Resource group id
- resource:9f889243e25b53c06ad1
- Deposit or zone
- Maria Bonita
- Mining method
- open_pit
- Material type
- saprolite
- Resource basis
- gross
Resource Data
- Category
- inferred
- Tonnes
- 1420000
- Grade
- 0.38
- Grade Unit
- g/t
- Contained Metal
- 17172
- Contained Unit
- oz
- Cutoff Grade
- 0.24
- Cutoff Unit
- g/t gold
Prior Estimate
- Resource Date
- 2026-09-16
Lab
- Laboratory
- SGS Geosol
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2026-09-21T00:00:00.000Z
Reasoning: Near-surface component.
Evidence · text
“Inferred Resources of 1.42Mt@0.38g/t (17,172oz)”
Tags used in scoring
Inferred Resourcenegative
Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone.
Why it applies: category is "inferred"
Cut-off Disclosedpositive
Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.
Why it applies: cutoff_grade is stated
QP/CP Signedpositive
Qualified Person (QP) or Competent Person (CP) named and signed off — a member of a recognized professional association (e.g., AusIMM, SME, AIG, P.Geo) with relevant experience.
Why it applies: qp_signed is true
NI 43-101 Compliantpositive
Resource estimate prepared in compliance with NI 43-101 (Canada) — high reporting standard.
Why it applies: reporting_standards includes ni_43_101
Resource Updateneutral
Revised estimate for an existing resource — compare to prior to assess progress.
Why it applies: the release compares against a previous estimate
How Atlas produces this analysis
Minestarters Atlas uses automated extraction to summarize mining announcements, identify reported measurements, and classify supporting evidence. Sentiment reflects the extracted narrative and classification rules; it is an interpretation, not a reported measurement. Evidence quotes and context are provided where available. Missing data, low-confidence results, and review flags indicate limitations. Check the original publisher announcement before relying on an interpretation.