# SONORO ANNOUNCES UPDATED MINERAL RESOURCE ESTIMATE AND ROBUST UPDATED PEA FOR CERRO CALICHE GOLD PROJECT: AFTER-TAX NPV OF USD $224 MILLION AND AFTER-TAX IRR OF 50%

Canonical Atlas analysis: https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8

Original source: https://money.tmx.com/en/quote/SGO/news/7704353287797242/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce

Publisher: tmx

Original announcement: 2026-02-28T13:00:00.000Z

Analysis by Minestarters Atlas

Atlas analysis published: Unknown date

Atlas analysis updated: Unknown date

- Company: Sonoro Gold Corp.

- Ticker: SGO

- Exchange: TSX

- Region: Sonora State, Mexico

- Primary commodity: Gold

- Secondary commodities: Silver

- Document categories: Resource update, Metallurgy

- Extracted: 2026-09-14 22:54:21 UTC

Narrative sentiment: 0.90 · Bullish

## Minestarters Atlas summary

Sonoro Gold Corp. announced an updated Mineral Resource Estimate and Preliminary Economic Assessment for its Cerro Caliche gold project in Sonora State, Mexico. The PEA outlines a robust open pit, heap leach operation with an after-tax NPV of $224 million and an IRR of 50% at base case prices. The updated MRE reports 51.75 Mt at 0.37 g/t Au and 3.7 g/t Ag \(644 koz AuEq\) in the Measured and Indicated categories, with an additional 8.8 Mt at 0.34 g/t AuEq \(97 koz AuEq\) Inferred.

Reasoning: The updated Mineral Resource Estimate and Preliminary Economic Assessment for the Cerro Caliche gold project demonstrate robust economics and increased resource confidence, supporting a viable open pit, heap leach operation.

- Positive factor: Robust project economics demonstrated by updated PEA with strong after-tax NPV and IRR

- Positive factor: Significant Measured and Indicated Mineral Resources reported

- Positive factor: NI 43-101 compliant and QP signed estimate

- Positive factor: Open pit, heap leach operation with strong gold recovery

- Positive factor: Potential for future expansion of mine capacity and LOM

- Negative factor: PEA is preliminary and includes Inferred Mineral Resources

- Negative factor: Silver recovery is low at 27%

- Negative factor: Only preliminary bench-scale testwork is implied for metallurgy

Facts used in scoring: 14

## Classification and evidence

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: Mineral Resources have been estimated in accordance with Canadian Institute of Mining and Metallurgy and Petroleum \("CIM"\) definitions, as required under National Instrument 43-101 \("NI43-101"\).

Evidence · text

> Mineral Resources have been estimated in accordance with Canadian Institute of Mining and Metallurgy and Petroleum \("CIM"\) definitions, as required under National Instrument 43-101 \("NI43-101"\).

**QP/CP Signed**

Polarity: positive

Definition: 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: Eugene Puritch, P.Eng, FEC, CET, Andrew Bradfield, P.Eng., William Stone, PhD, P.Geo., Fred Brown, P.Geo., Jarita Barry, P.Geo., David Burga, P.Geo., and D. Grant Feasby, P.Eng all of P&E Mining Consultants Inc. are independent of the Company and are Qualified Persons as defined in NI 43-101.

Evidence · text

> Eugene Puritch, P.Eng, FEC, CET, Andrew Bradfield, P.Eng., William Stone, PhD, P.Geo., Fred Brown, P.Geo., Jarita Barry, P.Geo., David Burga, P.Geo., and D. Grant Feasby, P.Eng all of P&E Mining Consultants Inc. are independent of the Company and are Qualified Persons as defined in NI 43-101.

**Measured Resource**

Polarity: positive

Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves.

Why it applies: The resource estimate includes a Measured category of 9,683 k tonnes at 0.41 g/t Au.

Evidence · table

> Measured

Context: 9,683

**Indicated Resource**

Polarity: positive

Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.

Why it applies: The resource estimate includes an Indicated category of 42,070 k tonnes at 0.36 g/t Au.

Evidence · table

> Indicated

Context: 42,070

**Inferred Resource**

Polarity: negative

Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone.

Why it applies: The resource estimate includes an Inferred category of 8,801 k tonnes at 0.33 g/t Au.

Evidence · table

> Inferred

Context: 8,801

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: Mineral Resources have been reported using a cut-off of 0.13 g/t AuEq.

Evidence · text

> Mineral Resources have been reported using a cut-off of 0.13 g/t AuEq.

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: The document title explicitly states "UPDATED MINERAL RESOURCE ESTIMATE".

Evidence · text

> UPDATED MINERAL RESOURCE ESTIMATE

**PEA-Supporting**

Polarity: neutral

Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.

Why it applies: The updated PEA utilizes the pit-constrained updated Mineral Resource Estimate prepared by P&E.

Evidence · text

> The updated PEA utilizes the pit-constrained updated Mineral Resource Estimate prepared by P&E.

**Heap Leach Route**

Polarity: neutral

Definition: Processing via heap leach — lower CAPEX and OPEX, lower recovery expected.

Why it applies: The PEA demonstrates the potential viability for an open pit, heap leach mining operation.

Evidence · text

> open pit, heap leach mining operation

**Strong Recovery**

Polarity: positive

Story-specific tag

Definition: No canonical definition is currently available.

Why it applies: Gold recovery of 72% for a heap leach operation is within the strong band \(65-75%\).

Evidence · text

> Gold recovery of 72%

**Low Recovery**

Polarity: negative

Definition: Recovery below the weak band for the commodity and processing route.

Why it applies: Silver recovery of 27% for a heap leach operation is below the weak band \(45%\).

Evidence · text

> silver recovery of 27%

**Bench Scale Only**

Polarity: negative

Definition: Only preliminary bench tests completed — no locked-cycle or pilot work.

Why it applies: The PEA is preliminary in nature and does not mention higher-scale metallurgical testwork like pilot or locked-cycle tests.

Evidence · text

> The updated PEA is preliminary in nature

**Mill Route**

Polarity: neutral

Definition: Processing via mill or concentrator \(CIL, CIP, tank leach, flotation\).

Why it applies: the document describes a flotation route \("concentrate"\)

## Extracted facts

Stored fact records: 14. Some facts used in scoring do not have a stored record.

## Resource Estimates (12)

### measured

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-resource-facts-0)

Cerro Caliche · gold

#### Identity

- Project: Cerro Caliche
- Commodity: gold
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Resource scope

- Estimate type: resource
- Effective date: 2025-12-04T00:00:00.000Z
- Reporting standards: ni\_43\_101
- QP Signed: Yes
- Qualified person names: Eugene Puritch, Andrew Bradfield, William Stone, Fred Brown, Jarita Barry, David Burga, D. Grant Feasby
- Resource group id: resource:1d8b74bb8a03c42a078c
- Mining method: combined

#### Resource Data

- Category: measured
- Tonnes: 9683000
- Grade: 0.43
- Grade Unit: g/t
- Contained Metal: 133000
- Contained Unit: oz
- Cutoff Grade: 0.13
- Cutoff Unit: g/t AuEq

#### Prior Estimate

- Resource Date: 2025-12-04

#### Metal Equivalent

- Metal Eq. Grade: 0.43
- Metal Eq. Unit: g/t AuEq
- Assumptions Disclosed: Yes

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The Measured gold equivalent resource provides a consolidated view of the high-confidence metal content.

- Positive factor: High confidence Measured category resource

- Positive factor: Metal equivalent grade provides a combined value for gold and silver

Evidence · table

> 0.43

Context: 9,683

#### Tags used in scoring

**Measured Resource**

Polarity: positive

Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves.

Why it applies: category is "measured"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: 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 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: the release compares against a previous estimate

**PEA-Supporting**

Polarity: neutral

Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.

Why it applies: the release names the study this estimate supports

### measured

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-resource-facts-1)

Cerro Caliche · silver

#### Identity

- Project: Cerro Caliche
- Commodity: silver
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Resource scope

- Estimate type: resource
- Effective date: 2025-12-04T00:00:00.000Z
- Reporting standards: ni\_43\_101
- QP Signed: Yes
- Qualified person names: Eugene Puritch, Andrew Bradfield, William Stone, Fred Brown, Jarita Barry, David Burga, D. Grant Feasby
- Resource group id: resource:1d8b74bb8a03c42a078c
- Mining method: combined

#### Resource Data

- Category: measured
- Tonnes: 9683000
- Grade: 3.5
- Grade Unit: g/t
- Contained Metal: 1086000
- Contained Unit: oz
- Cutoff Grade: 0.13
- Cutoff Unit: g/t AuEq

#### Prior Estimate

- Resource Date: 2025-12-04

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The Measured silver resource adds to the project's overall metal content and confidence.

- Positive factor: High confidence Measured category resource

Evidence · table

> 3.5

Context: 9,683

#### Tags used in scoring

**Measured Resource**

Polarity: positive

Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves.

Why it applies: category is "measured"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: 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 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: the release compares against a previous estimate

**PEA-Supporting**

Polarity: neutral

Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.

Why it applies: the release names the study this estimate supports

### indicated

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-resource-facts-2)

Cerro Caliche · gold

#### Identity

- Project: Cerro Caliche
- Commodity: gold
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Resource scope

- Estimate type: resource
- Effective date: 2025-12-04T00:00:00.000Z
- Reporting standards: ni\_43\_101
- QP Signed: Yes
- Qualified person names: Eugene Puritch, Andrew Bradfield, William Stone, Fred Brown, Jarita Barry, David Burga, D. Grant Feasby
- Resource group id: resource:38cd1ce7b68394231d6e
- Mining method: combined

#### Resource Data

- Category: indicated
- Tonnes: 42070000
- Grade: 0.38
- Grade Unit: g/t
- Contained Metal: 511000
- Contained Unit: oz
- Cutoff Grade: 0.13
- Cutoff Unit: g/t AuEq

#### Prior Estimate

- Resource Date: 2025-12-04

#### Metal Equivalent

- Metal Eq. Grade: 0.38
- Metal Eq. Unit: g/t AuEq
- Assumptions Disclosed: Yes

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The Indicated gold equivalent resource consolidates the metal content, enhancing the project's overall confidence.

- Positive factor: Large Indicated category resource provides significant confidence and scale

- Positive factor: Metal equivalent grade provides a combined value for gold and silver

Evidence · table

> 0.38

Context: 42,070

#### Tags used in scoring

**Indicated Resource**

Polarity: positive

Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.

Why it applies: category is "indicated"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: 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 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: the release compares against a previous estimate

**PEA-Supporting**

Polarity: neutral

Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.

Why it applies: the release names the study this estimate supports

### indicated

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-resource-facts-3)

Cerro Caliche · silver

#### Identity

- Project: Cerro Caliche
- Commodity: silver
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Resource scope

- Estimate type: resource
- Effective date: 2025-12-04T00:00:00.000Z
- Reporting standards: ni\_43\_101
- QP Signed: Yes
- Qualified person names: Eugene Puritch, Andrew Bradfield, William Stone, Fred Brown, Jarita Barry, David Burga, D. Grant Feasby
- Resource group id: resource:38cd1ce7b68394231d6e
- Mining method: combined

#### Resource Data

- Category: indicated
- Tonnes: 42070000
- Grade: 3.8
- Grade Unit: g/t
- Contained Metal: 5144000
- Contained Unit: oz
- Cutoff Grade: 0.13
- Cutoff Unit: g/t AuEq

#### Prior Estimate

- Resource Date: 2025-12-04

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The Indicated silver resource contributes to the overall metal content and confidence of the project.

- Positive factor: Large Indicated category resource adds significant confidence and scale

Evidence · table

> 3.8

Context: 42,070

#### Tags used in scoring

**Indicated Resource**

Polarity: positive

Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.

Why it applies: category is "indicated"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: 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 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: the release compares against a previous estimate

**PEA-Supporting**

Polarity: neutral

Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.

Why it applies: the release names the study this estimate supports

### inferred

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-resource-facts-4)

Cerro Caliche · gold

#### Identity

- Project: Cerro Caliche
- Commodity: gold
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Resource scope

- Estimate type: resource
- Effective date: 2025-12-04T00:00:00.000Z
- Reporting standards: ni\_43\_101
- QP Signed: Yes
- Qualified person names: Eugene Puritch, Andrew Bradfield, William Stone, Fred Brown, Jarita Barry, David Burga, D. Grant Feasby
- Resource group id: resource:40eeacc7f940420aa8e6
- Mining method: combined

#### Resource Data

- Category: inferred
- Tonnes: 8801000
- Grade: 0.34
- Grade Unit: g/t
- Contained Metal: 97000
- Contained Unit: oz
- Cutoff Grade: 0.13
- Cutoff Unit: g/t AuEq

#### Prior Estimate

- Resource Date: 2025-12-04

#### Metal Equivalent

- Metal Eq. Grade: 0.34
- Metal Eq. Unit: g/t AuEq
- Assumptions Disclosed: Yes

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The Inferred gold equivalent resource provides additional potential but with lower confidence, as noted in the PEA.

- Positive factor: Adds to the overall resource base

- Positive factor: Metal equivalent grade provides a combined value for gold and silver

- Negative factor: Inferred category has lower geological confidence

Evidence · table

> 0.34

Context: 8,801

#### Tags used in scoring

**Inferred Resource**

Polarity: negative

Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone.

Why it applies: category is "inferred"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: 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 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: the release compares against a previous estimate

**PEA-Supporting**

Polarity: neutral

Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.

Why it applies: the release names the study this estimate supports

### inferred

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-resource-facts-5)

Cerro Caliche · silver

#### Identity

- Project: Cerro Caliche
- Commodity: silver
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Resource scope

- Estimate type: resource
- Effective date: 2025-12-04T00:00:00.000Z
- Reporting standards: ni\_43\_101
- QP Signed: Yes
- Qualified person names: Eugene Puritch, Andrew Bradfield, William Stone, Fred Brown, Jarita Barry, David Burga, D. Grant Feasby
- Resource group id: resource:40eeacc7f940420aa8e6
- Mining method: combined

#### Resource Data

- Category: inferred
- Tonnes: 8801000
- Grade: 3.7
- Grade Unit: g/t
- Contained Metal: 1040000
- Contained Unit: oz
- Cutoff Grade: 0.13
- Cutoff Unit: g/t AuEq

#### Prior Estimate

- Resource Date: 2025-12-04

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The Inferred silver resource contributes to the overall metal content but with lower confidence.

- Positive factor: Adds to the overall resource base

- Negative factor: Inferred category has lower geological confidence

Evidence · table

> 3.7

Context: 8,801

#### Tags used in scoring

**Inferred Resource**

Polarity: negative

Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone.

Why it applies: category is "inferred"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: 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 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: the release compares against a previous estimate

**PEA-Supporting**

Polarity: neutral

Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.

Why it applies: the release names the study this estimate supports

### measured

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-resource-facts-8)

Cerro Caliche · gold

#### Identity

- Project: Cerro Caliche
- Commodity: gold
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Resource scope

- Estimate type: resource
- Effective date: 2025-12-04T00:00:00.000Z
- Reporting standards: ni\_43\_101
- QP Signed: Yes
- Qualified person names: Eugene Puritch, Andrew Bradfield, William Stone, Fred Brown, Jarita Barry, David Burga, D. Grant Feasby
- Resource group id: resource:d0cbf9b3879a4db4bfc7
- Mining method: combined

#### Resource Data

- Category: measured
- Tonnes: 9683
- Grade: 0.41
- Grade Unit: g/t
- Cutoff Grade: 0.13
- Cutoff Unit: g/t AuEq

#### Prior Estimate

- Resource Date: 2025-12-04

#### Metal Equivalent

- Metal Eq. Grade: 0.43
- Metal Eq. Unit: g/t AuEq
- Assumptions Disclosed: Yes

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The Measured gold resource provides high confidence and contributes significantly to the project's economics. \(Expanded from multi-commodity resource table for completeness.\)

- Positive factor: High confidence Measured category resource

- Positive factor: Good gold grade for an open pit heap leach operation

Evidence · table

> 0.41

Context: 9,683

#### Tags used in scoring

**Measured Resource**

Polarity: positive

Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves.

Why it applies: category is "measured"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: 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 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

**No Contained Metal**

Polarity: negative

Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting.

Why it applies: contained\_metal was not reported

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: the release compares against a previous estimate

**PEA-Supporting**

Polarity: neutral

Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.

Why it applies: the release names the study this estimate supports

### measured

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-resource-facts-9)

Cerro Caliche · silver

#### Identity

- Project: Cerro Caliche
- Commodity: silver
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Resource scope

- Estimate type: resource
- Effective date: 2025-12-04T00:00:00.000Z
- Reporting standards: ni\_43\_101
- QP Signed: Yes
- Qualified person names: Eugene Puritch, Andrew Bradfield, William Stone, Fred Brown, Jarita Barry, David Burga, D. Grant Feasby
- Resource group id: resource:d0cbf9b3879a4db4bfc7
- Mining method: combined

#### Resource Data

- Category: measured
- Tonnes: 9683
- Grade: 3.5
- Grade Unit: g/t
- Cutoff Grade: 0.13
- Cutoff Unit: g/t AuEq

#### Prior Estimate

- Resource Date: 2025-12-04

#### Metal Equivalent

- Metal Eq. Grade: 0.43
- Metal Eq. Unit: g/t AuEq
- Assumptions Disclosed: Yes

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The Measured gold resource provides high confidence and contributes significantly to the project's economics. \(Expanded from multi-commodity resource table for completeness.\)

- Positive factor: High confidence Measured category resource

- Positive factor: Good gold grade for an open pit heap leach operation

Evidence · table

> 3.5

Context: 9,683

#### Tags used in scoring

**Measured Resource**

Polarity: positive

Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves.

Why it applies: category is "measured"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: 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 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

**No Contained Metal**

Polarity: negative

Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting.

Why it applies: contained\_metal was not reported

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: the release compares against a previous estimate

**PEA-Supporting**

Polarity: neutral

Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.

Why it applies: the release names the study this estimate supports

### indicated

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-resource-facts-10)

Cerro Caliche · gold

#### Identity

- Project: Cerro Caliche
- Commodity: gold
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Resource scope

- Estimate type: resource
- Effective date: 2025-12-04T00:00:00.000Z
- Reporting standards: ni\_43\_101
- QP Signed: Yes
- Qualified person names: Eugene Puritch, Andrew Bradfield, William Stone, Fred Brown, Jarita Barry, David Burga, D. Grant Feasby
- Resource group id: resource:2757c6a75581c995e5c4
- Mining method: combined

#### Resource Data

- Category: indicated
- Tonnes: 42070
- Grade: 0.36
- Grade Unit: g/t
- Cutoff Grade: 0.13
- Cutoff Unit: g/t AuEq

#### Prior Estimate

- Resource Date: 2025-12-04

#### Metal Equivalent

- Metal Eq. Grade: 0.38
- Metal Eq. Unit: g/t AuEq
- Assumptions Disclosed: Yes

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The Indicated gold resource significantly increases the project's confidence and scale, supporting the PEA. \(Expanded from multi-commodity resource table for completeness.\)

- Positive factor: Large Indicated category resource adds significant confidence and scale

- Positive factor: Good gold grade for an open pit heap leach operation

Evidence · table

> 0.36

Context: 42,070

#### Tags used in scoring

**Indicated Resource**

Polarity: positive

Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.

Why it applies: category is "indicated"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: 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 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

**No Contained Metal**

Polarity: negative

Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting.

Why it applies: contained\_metal was not reported

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: the release compares against a previous estimate

**PEA-Supporting**

Polarity: neutral

Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.

Why it applies: the release names the study this estimate supports

### indicated

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-resource-facts-11)

Cerro Caliche · silver

#### Identity

- Project: Cerro Caliche
- Commodity: silver
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Resource scope

- Estimate type: resource
- Effective date: 2025-12-04T00:00:00.000Z
- Reporting standards: ni\_43\_101
- QP Signed: Yes
- Qualified person names: Eugene Puritch, Andrew Bradfield, William Stone, Fred Brown, Jarita Barry, David Burga, D. Grant Feasby
- Resource group id: resource:2757c6a75581c995e5c4
- Mining method: combined

#### Resource Data

- Category: indicated
- Tonnes: 42070
- Grade: 3.8
- Grade Unit: g/t
- Cutoff Grade: 0.13
- Cutoff Unit: g/t AuEq

#### Prior Estimate

- Resource Date: 2025-12-04

#### Metal Equivalent

- Metal Eq. Grade: 0.38
- Metal Eq. Unit: g/t AuEq
- Assumptions Disclosed: Yes

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The Indicated gold resource significantly increases the project's confidence and scale, supporting the PEA. \(Expanded from multi-commodity resource table for completeness.\)

- Positive factor: Large Indicated category resource adds significant confidence and scale

- Positive factor: Good gold grade for an open pit heap leach operation

Evidence · table

> 3.8

Context: 42,070

#### Tags used in scoring

**Indicated Resource**

Polarity: positive

Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.

Why it applies: category is "indicated"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: 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 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

**No Contained Metal**

Polarity: negative

Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting.

Why it applies: contained\_metal was not reported

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: the release compares against a previous estimate

**PEA-Supporting**

Polarity: neutral

Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.

Why it applies: the release names the study this estimate supports

### inferred

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-resource-facts-12)

Cerro Caliche · gold

#### Identity

- Project: Cerro Caliche
- Commodity: gold
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Resource scope

- Estimate type: resource
- Effective date: 2025-12-04T00:00:00.000Z
- Reporting standards: ni\_43\_101
- QP Signed: Yes
- Qualified person names: Eugene Puritch, Andrew Bradfield, William Stone, Fred Brown, Jarita Barry, David Burga, D. Grant Feasby
- Resource group id: resource:8a4dc5a38f3c713bd6c2
- Mining method: combined

#### Resource Data

- Category: inferred
- Tonnes: 8801
- Grade: 0.33
- Grade Unit: g/t
- Cutoff Grade: 0.13
- Cutoff Unit: g/t AuEq

#### Prior Estimate

- Resource Date: 2025-12-04

#### Metal Equivalent

- Metal Eq. Grade: 0.34
- Metal Eq. Unit: g/t AuEq
- Assumptions Disclosed: Yes

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The Inferred gold resource provides additional potential but carries lower confidence, as noted in the PEA. \(Expanded from multi-commodity resource table for completeness.\)

- Positive factor: Adds to the overall resource base

- Negative factor: Inferred category has lower geological confidence and cannot be converted to reserves

Evidence · table

> 0.33

Context: 8,801

#### Tags used in scoring

**Inferred Resource**

Polarity: negative

Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone.

Why it applies: category is "inferred"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: 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 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

**No Contained Metal**

Polarity: negative

Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting.

Why it applies: contained\_metal was not reported

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: the release compares against a previous estimate

**PEA-Supporting**

Polarity: neutral

Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study.

Why it applies: the release names the study this estimate supports

### inferred

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-resource-facts-13)

Cerro Caliche · silver

#### Identity

- Project: Cerro Caliche
- Commodity: silver
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Resource scope

- Estimate type: resource
- Effective date: 2025-12-04T00:00:00.000Z
- Reporting standards: ni\_43\_101
- QP Signed: Yes
- Qualified person names: Eugene Puritch, Andrew Bradfield, William Stone, Fred Brown, Jarita Barry, David Burga, D. Grant Feasby
- Resource group id: resource:8a4dc5a38f3c713bd6c2
- Mining method: combined

#### Resource Data

- Category: inferred
- Tonnes: 8801
- Grade: 3.7
- Grade Unit: g/t
- Cutoff Grade: 0.13
- Cutoff Unit: g/t AuEq

#### Prior Estimate

- Resource Date: 2025-12-04

#### Metal Equivalent

- Metal Eq. Grade: 0.34
- Metal Eq. Unit: g/t AuEq
- Assumptions Disclosed: Yes

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The Inferred gold resource provides additional potential but carries lower confidence, as noted in the PEA. \(Expanded from multi-commodity resource table for completeness.\)

- Positive factor: Adds to the overall resource base

- Negative factor: Inferred category has lower geological confidence and cannot be converted to reserves

Evidence · table

> 3.7

Context: 8,801

#### Tags used in scoring

**Inferred Resource**

Polarity: negative

Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone.

Why it applies: category is "inferred"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: 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 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

**No Contained Metal**

Polarity: negative

Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting.

Why it applies: contained\_metal was not reported

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: the release compares against a previous estimate

**PEA-Supporting**

Polarity: neutral

Definition: 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 (2)

### Fact 1

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-metallurgical-facts-6)

Cerro Caliche · gold

#### Identity

- Project: Cerro Caliche
- Commodity: gold
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Test Work

- Program Status: scoping
- Processing Route: heap leach

#### Recovery

- Recovery: 72 %
- Recovery Basis: actual\_test
- Head Grade: 0.36
- Head Grade Unit: g/t

#### Lab

- Consultant: P&E Mining Consultants Inc.

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The 72% gold recovery is strong for a heap leach operation and is a key positive factor for the project's economics.

- Positive factor: Strong gold recovery for a heap leach operation

- Positive factor: Supports the economic viability outlined in the PEA

- Negative factor: Preliminary nature of PEA implies bench-scale testwork

Evidence · text

> Gold recovery of 72%

#### Tags used in scoring

**Heap Leach Route**

Polarity: neutral

Definition: Processing via heap leach — lower CAPEX and OPEX, lower recovery expected.

Why it applies: processing\_route matches the heap\_leach signal

### Fact 2

[Link to this fact](https://atlas-extractions.minestarters.com/news/sonoro-announces-updated-mineral-resource-estimate-and-robust-updated-pea-for-ce--213ffe7b-0d83-4031-805e-cc001a9881d8#fact-metallurgical-facts-7)

Cerro Caliche · silver

#### Identity

- Project: Cerro Caliche
- Commodity: silver
- Region: mexico
- Reported Region: Sonora State, Mexico
- Ticker: SGO

#### Test Work

- Program Status: scoping
- Processing Route: heap leach

#### Recovery

- Recovery: 27 %
- Recovery Basis: actual\_test
- Head Grade: 3.7
- Head Grade Unit: g/t

#### Lab

- Consultant: P&E Mining Consultants Inc.

#### Location

- Loc. Confidence: medium

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-02-28T00:00:00.000Z

Reasoning: The 27% silver recovery is low for a heap leach operation, indicating potential for metal loss or requiring further optimization.

- Negative factor: Low silver recovery for a heap leach operation

- Negative factor: Preliminary nature of PEA implies bench-scale testwork

Evidence · text

> silver recovery of 27%

#### Tags used in scoring

**Heap Leach Route**

Polarity: neutral

Definition: Processing via heap leach — lower CAPEX and OPEX, lower recovery expected.

Why it applies: processing\_route matches the heap\_leach signal

**Low Recovery**

Polarity: negative

Definition: Recovery below the weak band for the commodity and processing route.

Why it applies: 27% is below the weak band \(75%\)

## 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.