Mexico

Cerro Las Minitas Project

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Overview

Mine TypeUnderground
StagePreliminary Economic Assessment
Commodities
  • Silver
  • Gold
  • Lead
  • Zinc
  • Copper
Mining Method
  • Longitudinal stoping
  • Transverse stoping
  • Longhole open stoping
  • Cemented paste backfill
  • Undefined backfill
Mine Life15 years (as of Jan 1, 2022)
ShapshotCerro Las Minitas is one of the Largest and Highest Grade Undeveloped Silver Projects in the World.

270,000 tonnes of Au-Ag-enriched oxide mineralization is not included in the flowsheet. In Q2 2023 the Southern Silver initiated a metallurgical test program to understand gold deportment in both the sulphide and oxide resources.

The atmospheric leach has demonstrated what is likely the most cost-effective gold extraction technique which can be easily incorporated into future financial modelling of the project.

Owners

SourceSource
CompanyInterestOwnership
Southern Silver Exploration Corp. 100 % Indirect
Cerro Las Minitas Project is 100% owned by Southern Silver.

Southern Silver through its subsidiary Minera Plata del Sur, S.A. de C.V. (“MPS”) acquired a 100% interest in the claims. MPS is now the registered title holder of the claims.

Contractors

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Deposit type

  • Skarn
  • Manto

Summary:

From 2010-2021 Southern Silver completed programs of geological mapping, surface geochemical sampling and airborne and ground geophysical surveys in support of 80,904 m of core drilling in 186 holes resulting in the delineation of six mineral deposits: the Blind; El Sol, Las Victorias, Skarn Front, South Skarn and Mina La Bocona deposits on the Cerro Las Minitas Property. The Blind, El Sol and Las Victorias deposits comprise multiple sub-vertical northwest-southeast trending zones of semi massive to massive sulphide mineralization. Mineralization is hosted in the skarnoid- and hornfels-altered margins of monzonite and felsite dykes and may be localized along through-going structures or occur as replacements within stratigraphic units. The mineralized zones can be traced for up to 1000 m along strike and up to 800 m down dip. Sulphide mineralization in the Skarn Front deposit is localized at the outer boundary of the skarnoid alteration zone surrounding the Central Monzonite Intrusion at or near the transition to the recrystallized/marbleized carbonate sediments (marmorized zone). The Skarn Front deposit can be traced for up to 1,100 m along strike and up to 1,000 metres depth. Geological modelling suggests that intersections between the sub-vertical, northwest-trending Blind and El Sol mineralized zones and the generally more shallowly dipping Skarn Front may localize higher-grade shoots of mineralization. Drilling in 2020-22 confirmed laterally extensive skarnoid-style mineralization within the altered halo around the central intrusion in the South Skarn, La Bocona and North Felsite deposits. Mineralization occurs adjacent to the central intrusion and features similar replacement styles as is observed in the Skarn Front deposit. The skarnoid-style mineralization in the La Bocona and South Skarn deposits show a similar variability in metal assemblages as is identified in the Skarn Front deposit, but tends to be more galena biased and is generally associated with elevated silver values when compared to the Skarn Front mineralization. Mineralization in the North Felsite also show a similar variability in metal assemblage, but drilling is currently insufficient to define the mineral zonation accurately. Drilling also identified manto-styled mineralization within the La Bocona deposit which occurs as replacements in the hanging wall of the skarnoid mineralized zone within variably altered marble-skarn-hornfels. The mineralization is strongly silver enriched with elevated lead, arsenic, and gold values. The upper portion of the mineralized zone is strongly oxidized and makes up in part the small oxide resource. To date, mineralization at Cerro Las Minitas has been classified into four types based on surface and underground field observations and the examination of drill core: skarnoid, chimney, manto, and dyke margin. At Cerro Las Minitas, contact metasomatic gold, silver, zinc, lead and copper mineralization formed within the altered sediments adjacent to contacts with the central intrusive complex or larger dykes. Drilling in 2016/17 by Southern Silver discovered that skarnoid mineralization is more continuous at depth, beneath the projections of the Blind and El Sol mineralized zones. Mineralization is localized at the outer boundary of the garnet pyroxene-wollastonite-epidote skarnoid assemblage at or near the transition to the recrystallized/marbleized carbonate sediments (marmorized zone) in an area referred to as the Skarn Front. Mineralization at the outer edge of the Skarn Front tends to be more lead and silver-enriched while mineralization deeper in the skarnoid zone (and adjacent to the central intrusion) more zinc enriched. Drilling in 2020-22 confirmed laterally extensive skarnoid-style mineralization within the altered halo around the central intrusion in the South Skarn, La Bocona and North Felsite deposits. Mineralization occurs adjacent to the central intrusion and features similar replacement styles as is observed in the Skarn Front deposit. The skarnoid-style mineralization in the La Bocona and South Skarn deposits show a similar variability in metal assemblages as is identified in the Skarn Front deposit, but tends to be more galena biased and is generally associated with elevated silver values when compared to the Skarn Front mineralization. Mineralization in the North Felsite also show a similar variability in metal assemblage, but drilling is currently insufficient to define the mineral zonation accurately. Cerro Las Minitas Property straddles the geomorphic provinces of the Sierra Madre Occidental and the Mesa Central (Altiplano) of Mexico in the State of Durango. In Durango, the Mesa Central is an elevated plateau at about 2,000 metres elevation traversed by NW-trending mountain ranges and separated by broad NW-trending valleys. Within this province, Cerro Las Minitas occurs within a belt of prolific Au, Ag, Pb, Zn and Cu deposits that stretches from the highly productive vein deposits of Fresnillo in Zacatecas in the south, to the massive manto deposits of Santa Eulalia in Chihuahua to the north. The Cerro Las Minitas project is located within the Guadalupe Victoria Mining Region, which includes the districts of Avino (Avino Gold and Silver Mines Ltd.), San Sebastian (Hecla Mining Ltd.) and Cerro Las Minitas that constitute a trend of deposits and workings along a 50-kilometre northwest trend. The Cerro Las Minitas property lies within the Minitas Mining District. An aureole of contact metasomatic and replacement deposits of Au, Ag, Pb, Zn, and Cu was produced during the emplacement of the intrusives and is the subject of past mining activities and exploration currently underway at the Cerro Las Minitas Project. Much of mineralization appears to be localized at the Skarn-Marble boundary, where many of the radial faults/fractures are located. Good structural preparation explains the consistency of mineralization within drillholes around the central intrusion. Although detailed structural paragenetic interpretation is ongoing, intersection of N-S, NE-SW and NW-SE structures with the radial faults and fractures around the circumference of the central intrusion appear to localize thicker and higher-grade zones of mineralization. A major regional NW-SE structure localizes a suite of monzonite and felsite dykes in the Blind-El Sol Zone. Mineralization occurs as replacements on dyke margins and in sub-vertical structures that locally channel the intrusions. Here as well, structural intersection may localize thicker and higher grade skarn mineralization. Other Aplite-Monzonite dyke swarms have been mapped around the central intrusion with NNW-SSE and WSW-ENE orientations and may explain some of the hanging wall mineralization drilled outboard of the skarn front. Many dykes are identified outboard of the central intrusion and have not been well drilled and provide other shallow, but higher risk exploration targets.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

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Processing

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Production

CommodityProductUnitsDailyAvg. AnnualLOM
Silver Payable metal koz 70,816
Silver Metal in concentrate koz 5,30079,184
Lead Concentrate kt 000357
Lead Payable metal M lbs 485
Zinc Concentrate kt 001,094
Zinc Payable metal M lbs 1,097
Copper Concentrate kt 000109
Copper Payable metal M lbs 62
Silver Equivalent Metal in concentrate M oz 13190

Operational metrics

Metrics
Daily processing rate 0000
Daily processing capacity 0000
Annual processing capacity 0000000
Tonnes processed 00000
Waste tonnes, LOM 0000
Ore tonnes mined, LOM 00000
Total tonnes mined, LOM 00000
* According to 2022 study.

Production Costs

CommodityUnitsAverage
All-in sustaining costs (AISC) Silver Equivalent USD 000
All-in sustaining costs (sold) Silver Equivalent USD 000
Assumed price Lead USD 000
Assumed price Zinc USD 000
Assumed price Copper USD 000
Assumed price Silver USD 00
* According to 2022 study / presentation.

Operating Costs

Currency2022
UG mining costs ($/t milled) USD 38.7 *  
Processing costs ($/t milled) USD  ....  Subscribe
G&A ($/t milled) USD  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe
* According to 2022 study.

Project Costs

MetricsUnitsLOM Total
Initial CapEx $M USD  ......  Subscribe
Sustaining CapEx $M USD  ......  Subscribe
Closure costs $M USD  ......  Subscribe
Total CapEx $M USD  ......  Subscribe
UG OpEx $M USD  ......  Subscribe
Processing OpEx $M USD 369.6
Refining costs $M USD  ......  Subscribe
G&A costs $M USD 87.8
Total OpEx $M USD  ......  Subscribe
Income Taxes $M USD  ......  Subscribe
Total Taxes $M USD  ......  Subscribe
Gross revenue (LOM) $M USD  ......  Subscribe
Net Operating Income (LOM) $M USD  ......  Subscribe
Net Income (LOM) $M USD  ......  Subscribe
Pre-tax Cash Flow (LOM) $M USD  ......  Subscribe
After-tax Cash Flow (LOM) $M USD  ......  Subscribe
Pre-tax NPV @ 5% $M USD  ......  Subscribe
Pre-tax NPV @ 10% $M USD  ......  Subscribe
Pre-tax NPV @ 8% $M USD  ......  Subscribe
After-tax NPV @ 5% $M USD  ......  Subscribe
After-tax NPV @ 10% $M USD  ......  Subscribe
After-tax NPV @ 8% $M USD  ......  Subscribe
Pre-tax IRR, %  ......  Subscribe
After-tax IRR, %  ......  Subscribe
Pre-tax payback period, years  ......  Subscribe
After-tax payback period, years  ......  Subscribe

Heavy Mobile Equipment

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Personnel

Mine Management

Source Source
Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Aug 29, 2022
....................... Subscription required ....................... Subscription required Subscription required Aug 29, 2022

EmployeesContractorsTotal WorkforceYear
Subscription required Subscription required Subscription required 2022

Aerial view:

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