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 12:33:18 UTC
Analysis by Minestarters Atlas
Minestarters Atlas analysis
Summary
Altamira Gold Corp. has announced an updated Mineral Resource Estimate for the Maria Bonita porphyry gold deposit in Brazil, showing a 90% increase in total tonnage and an 82% increase in contained gold compared to the 2025 maiden estimate. The Indicated resource now stands at 25Mt @ 0.50g/t gold, while Inferred resources have expanded to 70Mt @ 0.41g/t gold.
Reasoning: The update shows massive scale expansion for the Maria Bonita deposit, with both tonnage and contained ounces increasing significantly compared to the maiden estimate.
Positive factors
- Significant tonnage growth (90%)
- Substantial contained gold increase (82%)
- Strong Inferred category growth (150%)
- Expansion of high-grade sector
- Open mineralized system
Facts used in scoring: 4
Classification and evidence
Tonnage Growthpositive
Tonnage increase reaching the strong tier vs prior estimate, with grade maintained or improved.
Why it applies: Total resource tonnage increased by 90% compared to the 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%”
Category Upgradepositive
Resource confidence improved — Inferred upgraded to Indicated, or Indicated to Measured. De-risking signal.
Why it applies: The release highlights significant growth in both Indicated and Inferred categories.
Evidence · text
“represents a 150% increase in the contained ounces in the Inferred category and a 12% increase in contained ounces in the Indicated category”
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: Volodymyr Myadzel and Fernando Benegas are named as Qualified Persons.
Evidence · text
“under the direction of Volodymyr Myadzel, PhD, MAIG, a consultant to the Company and a Qualified Person”
Cut-off Disclosedpositive
Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.
Why it applies: The MRE is reported at a cut-off grade of 0.24 g/t gold.
Evidence · text
“reported at a cut-off grade of 0.24 g/t gold”
Resource Updateneutral
Revised estimate for an existing resource — compare to prior to assess progress.
Why it applies: The source explicitly discloses a revised resource estimate
Evidence · text
“updated Mineral Resource Estimate”
Extracted facts
Stored fact records: 4. Some facts used in scoring do not have a stored record.
Resource Estimates (4)
indicatedMaria Bonita · goldTonnes: 25000000Grade: 0.5Grade Unit: g/tContained Metal: 403877Contained Unit: ozView all detailsHide details
Identity
- Project
- Maria Bonita
- 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:0a30bcf2b2f5a43e720a
- Deposit or zone
- Maria Bonita
- Mining method
- open_pit
- Material type
- fresh
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
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2026-09-21T00:00:00.000Z
Reasoning: Strong Indicated resource 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
inferredMaria Bonita · goldTonnes: 70000000Grade: 0.41Grade Unit: g/tContained Metal: 908477Contained Unit: ozView all detailsHide details
Identity
- Project
- Maria Bonita
- 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:021aa7b8b77894f24bf4
- Deposit or zone
- Maria Bonita
- Mining method
- open_pit
- Material type
- fresh
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
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2026-09-21T00:00:00.000Z
Reasoning: Large scale expansion in the Inferred category.
Positive factors
- Massive expansion of Inferred scale
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
indicatedMaria Bonita · goldTonnes: 1490000Grade: 0.65Grade Unit: g/tContained Metal: 30899Contained Unit: ozView all detailsHide details
Identity
- Project
- Maria Bonita
- 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:9e56f768a445029223fd
- Deposit or zone
- Maria Bonita
- Mining method
- open_pit
- Material type
- saprolite
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
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2026-09-21T00:00:00.000Z
Reasoning: Near-surface saprolite resource provides early access potential.
Positive factors
- Higher grade near-surface component
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
inferredMaria Bonita · goldTonnes: 1420000Grade: 0.38Grade Unit: g/tContained Metal: 17172Contained Unit: ozView all detailsHide details
Identity
- Project
- Maria Bonita
- 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:d730c7558d5cdca4beb9
- Deposit or zone
- Maria Bonita
- Mining method
- open_pit
- Material type
- saprolite
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
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2026-09-21T00:00:00.000Z
Reasoning: Near-surface saprolite 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.