ATAC Announces Updated Resource Estimate for the Osiris Deposit, Yukon
Original announcement by tmx on
- Company
- ATAC Resources Ltd.
- Ticker
- ATC
- Exchange
- TSX
- Region
- Yukon
- Primary commodity
- Gold
- Secondary commodities
- None reported
- Document categories
- Resource update, Metallurgy
- Extracted
- 2026-09-17 11:43:38 UTC
Analysis by Minestarters Atlas
Minestarters Atlas analysis
Summary
ATAC Resources Ltd. has released an updated Mineral Resource Estimate for its Osiris Deposit in Yukon, reporting 732,000 Indicated ounces of gold at 4.12 g/t and 1,044,000 Inferred ounces of gold at 3.47 g/t. This update successfully converted 43% of the 2018 maiden Inferred Resource to the Indicated category, leading to an overall increase in contained gold ounces. Comprehensive metallurgical testwork confirmed viable processing paths for the refractory Carlin-style mineralization, with projected overall gold recoveries of 83% and up to 92% for specific methods.
Reasoning: ATAC Resources announced an updated resource estimate for its Osiris Deposit, showing a significant upgrade of 43% of the 2018 Inferred resource to the Indicated category, increasing total contained gold ounces. Metallurgical testwork confirmed viable processing routes for the refractory Carlin-style mineralization with strong gold recoveries, although one route noted high acid consumption. The overall average grade of the total resource declined compared to the prior estimate.
Positive factors
- Significant conversion of Inferred resources to Indicated category (43%)
- Overall contained gold ounces increased from prior estimate
- High-grade nature of the deposit (Carlin-style)
- Viable processing paths confirmed with strong gold recoveries for refractory ore
- Multiple zones remain open for extension
Negative factors
- Overall average grade of the total resource decreased compared to the prior Inferred estimate
- High acid consumption noted for one of the processing routes (acid pressure oxidation)
- No specific effective date provided for the current resource estimate
Low confidence — this extraction should be reviewed alongside the original source.
Facts used in scoring: 7
Classification and evidence
Cut-off Disclosedpositive
Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.
Why it applies: A current resource fact retains the disclosed cut-off grade
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 Resource Estimate”
Mill Routeneutral
Processing via mill or concentrator (CIL, CIP, tank leach, flotation).
Why it applies: the document describes a flotation route ("flotation")
POX/BIOX Routeneutral
Pressure or bio-oxidation for refractory ore — high CAPEX and OPEX.
Why it applies: the document describes a pox_biox route ("pressure oxidation")
Extracted facts
Stored fact records: 7. Some facts used in scoring do not have a stored record.
Resource Estimates (6)
indicatedOsiris Deposit, Rackla Gold Property · goldTonnes: 4658000Grade: 604000Grade Unit: ouncesContained Metal: 604000Contained Unit: ozView all detailsHide details
Identity
- Project
- Osiris Deposit, Rackla Gold Property
- Commodity
- gold
- Region
- canada_yt
- Reported Region
- Yukon
- Ticker
- ATC
Resource scope
- Estimate type
- resource
- Reporting standards
- ni_43_101
- QP Signed
- Yes
- Qualified person names
- Steven Ristorcelli
- Resource group id
- resource:594f226087668a88c5cd
- Mining method
- open_pit
- Ownership percent
- 100 %
Resource Data
- Category
- indicated
- Tonnes
- 4658000
- Grade
- 604000
- Grade Unit
- ounces
- Contained Metal
- 604000
- Contained Unit
- oz
- Cutoff Grade
- 1
- Cutoff Unit
- g/t
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2022-07-28T00:00:00.000Z
Reasoning: This represents a substantial portion of the newly upgraded Indicated resource, with a strong grade for an open-pit scenario, contributing significantly to the overall resource confidence.
Positive factors
- High-grade open-pit indicated resource
- Contributes to significant category upgrade from prior estimate
Evidence · table
“604,000”
Context: 4,658,000
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
PEA-Supportingneutral
Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.
Why it applies: the release names the study this estimate supports
indicatedOsiris Deposit, Rackla Gold Property · goldTonnes: 870400Grade: 128000Grade Unit: ouncesContained Metal: 128000Contained Unit: ozView all detailsHide details
Identity
- Project
- Osiris Deposit, Rackla Gold Property
- Commodity
- gold
- Region
- canada_yt
- Reported Region
- Yukon
- Ticker
- ATC
Resource scope
- Estimate type
- resource
- Reporting standards
- ni_43_101
- QP Signed
- Yes
- Qualified person names
- Steven Ristorcelli
- Resource group id
- resource:07816c4e419bfd3202de
- Mining method
- underground
- Ownership percent
- 100 %
Resource Data
- Category
- indicated
- Tonnes
- 870400
- Grade
- 128000
- Grade Unit
- ounces
- Contained Metal
- 128000
- Contained Unit
- oz
- Cutoff Grade
- 2
- Cutoff Unit
- g/t
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2022-07-28T00:00:00.000Z
Reasoning: This high-grade underground indicated resource adds to the overall confidence and flexibility of the deposit, contributing to the significant category upgrade.
Positive factors
- High-grade underground indicated resource
- Contributes to significant category upgrade from prior estimate
Evidence · table
“128,000”
Context: 870,400
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
PEA-Supportingneutral
Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.
Why it applies: the release names the study this estimate supports
indicatedOsiris Deposit, Rackla Gold Property · goldTonnes: 5528400Grade: 732000Grade Unit: ouncesContained Metal: 732000Contained Unit: ozView all detailsHide details
Identity
- Project
- Osiris Deposit, Rackla Gold Property
- Commodity
- gold
- Region
- canada_yt
- Reported Region
- Yukon
- Ticker
- ATC
Resource scope
- Estimate type
- resource
- Reporting standards
- ni_43_101
- QP Signed
- Yes
- Qualified person names
- Steven Ristorcelli
- Resource group id
- resource:68f2ff02fdc2e9bae864
- Mining method
- combined
- Ownership percent
- 100 %
Resource Data
- Category
- indicated
- Tonnes
- 5528400
- Grade
- 732000
- Grade Unit
- ounces
- Contained Metal
- 732000
- Contained Unit
- oz
Prior Estimate
- Prior Tonnes
- 12387077.51
- Prior Grade
- 4.23
- Prior Contained Metal
- 1685000
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2022-07-28T00:00:00.000Z
Reasoning: The conversion of a large portion of the prior Inferred resource to Indicated is a strong de-risking signal, significantly improving the confidence in the project's economics, despite a slight decrease in overall average grade.
Positive factors
- Significant category upgrade (43% of 2018 Inferred converted to Indicated)
- Substantial Indicated contained gold ounces
- High average grade for a total resource
Negative factors
- Overall average grade of the total resource (Indicated + Inferred) decreased compared to the prior Inferred estimate
Evidence · table
“732,000”
Context: 5,528,400
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 Undisclosednegative
High-grade interval reported without stating the cut-off grade used for compositing.
Why it applies: no cutoff_grade was 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
Tonnage Declinenegative
Resource tonnage decreased vs prior estimate — pit optimization removed marginal material or geological model revised down.
Why it applies: 5528400 against 12387077.51 previously
Grade Improvementpositive
Average resource grade improved vs prior estimate — better deposit economics.
Why it applies: 732000 against 4.23 previously
Contained Metal Declinenegative
Contained metal decreased vs prior despite tonnage growth — grade dilution exceeds volume gain.
Why it applies: 732000 against 1685000 previously
Resource Updateneutral
Revised estimate for an existing resource — compare to prior to assess progress.
Why it applies: the release compares against a previous estimate
PEA-Supportingneutral
Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.
Why it applies: the release names the study this estimate supports
inferredOsiris Deposit, Rackla Gold Property · goldTonnes: 5370000Grade: 530000Grade Unit: ouncesContained Metal: 530000Contained Unit: ozView all detailsHide details
Identity
- Project
- Osiris Deposit, Rackla Gold Property
- Commodity
- gold
- Region
- canada_yt
- Reported Region
- Yukon
- Ticker
- ATC
Resource scope
- Estimate type
- resource
- Reporting standards
- ni_43_101
- QP Signed
- Yes
- Qualified person names
- Steven Ristorcelli
- Resource group id
- resource:80de882fdc5484d951f2
- Mining method
- open_pit
- Ownership percent
- 100 %
Resource Data
- Category
- inferred
- Tonnes
- 5370000
- Grade
- 530000
- Grade Unit
- ounces
- Contained Metal
- 530000
- Contained Unit
- oz
- Cutoff Grade
- 1
- Cutoff Unit
- g/t
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2022-07-28T00:00:00.000Z
Reasoning: This inferred open-pit resource adds substantial ounces to the project's potential, maintaining a reasonable grade for future exploration and conversion.
Positive factors
- Adds significant ounces to the overall resource base
- Good grade for an open-pit inferred resource
Evidence · table
“530,000”
Context: 5,370,000
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
PEA-Supportingneutral
Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.
Why it applies: the release names the study this estimate supports
inferredOsiris Deposit, Rackla Gold Property · goldTonnes: 3990000Grade: 514000Grade Unit: ouncesContained Metal: 514000Contained Unit: ozView all detailsHide details
Identity
- Project
- Osiris Deposit, Rackla Gold Property
- Commodity
- gold
- Region
- canada_yt
- Reported Region
- Yukon
- Ticker
- ATC
Resource scope
- Estimate type
- resource
- Reporting standards
- ni_43_101
- QP Signed
- Yes
- Qualified person names
- Steven Ristorcelli
- Resource group id
- resource:2812e032cb07fd421e6e
- Mining method
- underground
- Ownership percent
- 100 %
Resource Data
- Category
- inferred
- Tonnes
- 3990000
- Grade
- 514000
- Grade Unit
- ounces
- Contained Metal
- 514000
- Contained Unit
- oz
- Cutoff Grade
- 2
- Cutoff Unit
- g/t
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2022-07-28T00:00:00.000Z
Reasoning: This inferred underground resource provides additional ounces at a good grade, indicating potential for future development and resource expansion.
Positive factors
- Adds significant ounces to the overall resource base
- Good grade for an underground inferred resource
Evidence · table
“514,000”
Context: 3,990,000
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
PEA-Supportingneutral
Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.
Why it applies: the release names the study this estimate supports
inferredOsiris Deposit, Rackla Gold Property · goldTonnes: 9360000Grade: 1044000Grade Unit: ouncesContained Metal: 1044000Contained Unit: ozView all detailsHide details
Identity
- Project
- Osiris Deposit, Rackla Gold Property
- Commodity
- gold
- Region
- canada_yt
- Reported Region
- Yukon
- Ticker
- ATC
Resource scope
- Estimate type
- resource
- Reporting standards
- ni_43_101
- QP Signed
- Yes
- Qualified person names
- Steven Ristorcelli
- Resource group id
- resource:8601a69fa52305548aaf
- Mining method
- combined
- Ownership percent
- 100 %
Resource Data
- Category
- inferred
- Tonnes
- 9360000
- Grade
- 1044000
- Grade Unit
- ounces
- Contained Metal
- 1044000
- Contained Unit
- oz
Prior Estimate
- Prior Tonnes
- 12387077.51
- Prior Grade
- 4.23
- Prior Contained Metal
- 1685000
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2022-07-28T00:00:00.000Z
Reasoning: The Inferred resource provides significant future potential, contributing to the overall contained metal growth, but the decrease in average grade compared to the prior estimate warrants attention.
Positive factors
- Substantial Inferred contained gold ounces
- Contributes to overall contained metal growth
Negative factors
- Overall average grade of the total resource (Indicated + Inferred) decreased compared to the prior Inferred estimate
Evidence · table
“1,044,000”
Context: 9,360,000
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 Undisclosednegative
High-grade interval reported without stating the cut-off grade used for compositing.
Why it applies: no cutoff_grade was 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
Tonnage Declinenegative
Resource tonnage decreased vs prior estimate — pit optimization removed marginal material or geological model revised down.
Why it applies: 9360000 against 12387077.51 previously
Grade Improvementpositive
Average resource grade improved vs prior estimate — better deposit economics.
Why it applies: 1044000 against 4.23 previously
Contained Metal Declinenegative
Contained metal decreased vs prior despite tonnage growth — grade dilution exceeds volume gain.
Why it applies: 1044000 against 1685000 previously
Resource Updateneutral
Revised estimate for an existing resource — compare to prior to assess progress.
Why it applies: the release compares against a previous estimate
PEA-Supportingneutral
Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.
Why it applies: the release names the study this estimate supports
Metallurgical Results (1)
pressure oxidationOsiris Deposit, Rackla Gold Property · goldRecovery: 92 %View all detailsHide details
Identity
- Project
- Osiris Deposit, Rackla Gold Property
- Commodity
- gold
- Region
- canada_yt
- Reported Region
- Yukon
- Ticker
- ATC
Test Work
- Program Status
- detailed
- Test Type
- pressure oxidation
- Processing Route
- acid pressure oxidation and cyanidation
Recovery
- Recovery
- 92 %
- Recovery Basis
- actual_test
Lab
- Laboratory
- Blue Coast Research
- Consultant
- Blue Coast Research
Review
- Needs Review
- No
- Historical
- No
Dates
- Event date
- 2022-07-28T00:00:00.000Z
Reasoning: Achieving an exceptional 92% gold recovery with acid pressure oxidation is a strong technical result, but the high acid consumption due to carbonate content presents a potential economic challenge that needs optimization.
Positive factors
- Exceptional recovery for refractory ore via acid pressure oxidation
Negative factors
- High acid consumption due to elevated carbonate content
Evidence · text
“up to 92% recovery after cyanidation. However, the elevated carbonate content of the feed material incurs a high acid consumption.”
Tags used in scoring
POX/BIOX Routeneutral
Pressure or bio-oxidation for refractory ore — high CAPEX and OPEX.
Why it applies: processing_route matches the pox_biox signal
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.