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Southern Silver Provides Mineral Resource Update that Includes Newly Identified Shallow High-grade Deposit at the Cerro Las Minitas Project

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Southern Silver Provides Mineral Resource Update that Includes Newly Identified Shallow High-grade Deposit at the Cerro Las Minitas Project






Mineral Resource Update:


Indicated 140Mozs AgEq or 2.3Blbs ZnEq: 42.7Mozs Ag, 364Mlbs Pb, and 903Mlbs Zn; and


Inferred 210Mozs AgEq or 3.5Blbs ZnEq: 80.0Mozs Ag, 571Mlbs Pb, and 1,029Mlbs Zn


Southern Silver Exploration Corp. (TSX-V:SSV) (OTCQX:SSVFF) reports that Kirkham Geosystems Ltd. has completed an update of its independent Mineral Resource Estimate on the Cerro Las Minitas project in Durango State, Mexico. The updated MRE significantly expands sulphide resources in the La Bocona deposit through the incorporation of the North Felsite zone into the resource model. The revised estimate utilizes the same metal pricing and metallurgical recoveries as the previous 2021 MRE, utilizes a Net Smelter Return cut-off, as detailed in Table 1, and reports average grades on a AgEq, ZnEq and $US/t NSR basis. The Mineral Resource estimates for the South Skarn, Blind-El Sol Skarn Front and Las Victorias deposits and the small oxide resource initially estimated in 2021, remains unchanged in this current update.


The newly modelled mineral resources represent an approximate 63% increase in the size of the La Bocona deposit (on a AgEq basis) and an overall 4.5% increase in the mineral resources of the entire project.


The now extended La Bocona deposit projects laterally along the eastern margin of the central intrusion and together with the previously identified South Skarn deposit forms a 1,200 metre long, semi-continuous zone of mineralization featuring three separate higher-grade “shoots” which project to 500m below surface and remain open at depth for further resource expansion (Figure 1).


Vice President of Exploration, Rob Macdonald stated “ This latest resource update represents one more step in the continued evolution of the Cerro La Minitas project through the identification of further shallow, high-grade mineralization which is accretive to the existing mineral resources on the property and adjacent to the planned project infrastructure. Future work will maintain a focus on adding value to the project early in the production time-line for maximum economic benefit. This includes: further engineering upgrades to the project design; a detailed review of the capital expenditures; the addition of gold payables to the cash-flow model; and pre-concentration to improve the project economics. Mineralization remains open at depth, particularly on the eastern side of the Cerro which with further exploration can continue to add high margin mineralization early in the production scenario.”


Figure 1: South Skarn and La Bocona deposits looking southwest at NSR = US$60/t, US$90/t and US$150/t cut-offs. Mineralization now extends over 1200m along strike on the east side of the Cerro.



Resource Model Highlights:


Compared to the 2021 Mineral Resource estimate, the 2023 update, at a US$60/t NSR cut-off, features:

  • Indicated Mineral Resources: A 0.18Mt increase to 12.5Mt averaging 106g/t Silver, 0.07g/t Gold, 0.2% Copper, 1.3% Lead and 3.3% Zinc (349g/t AgEq; 8.5% ZnEq) equalling a US$130/t NSR value, containing:42.7 million ounces of silver; 29 thousand ounces of gold; 46 million pounds of copper, 364 million pounds of lead; and 903 million pounds of zinc.

    This equates to 140 million ounces silver equivalent or 2.3 billion pounds zinc equivalent; and

  • Inferred Mineral Resources: A 1.4Mt increase to 21.0Mt averaging 118g/t Silver, 0.1g/t Gold, 0.2% Copper, 1.2% Lead and 2.2% Zinc (311g/t AgEq; 7.6% ZnEq) equalling a US$123/t NSR value containing:80.0 million ounces of silver; 85 thousand ounces of gold; 101 million pounds of copper, 571 million pounds of lead; and 1,029 million pounds of zinc (1.03 billion pounds Zn).

    This equates to 210 million ounces silver equivalent or 3.5 billion pounds zinc equivalent.


The new Mineral Resource Estimate incorporates results from 26 additional drill holes totalling 11,801.5 metres which tested the north-western extension the La Bocona deposit. Mineralization was also identified in several holes specifically along the northern margin of the central intrusion that were not incorporated into the new resource update and with further drilling, represent additional expansion opportunities.


NSR Calculation Parameters


The NSR values were calculated using average long-term prices of $20/oz. silver, $1,650/oz. gold, $3.25/lb. copper, $1.00/lb. lead and $1.20/lb. zinc. Metallurgical test work identified three saleable concentrates for the Skarn zones and two from the Blind, El Sol and Las Victorias zones (BESS). NSR values for each concentrate were calculated utilizing the parameters summarized in Table 1 and summed to determine a total NSR value for each block.


Gold recovery was not assessed in the sulphide concentrates and as a result was not included in the NSR calculation. Work is proceeding to determine gold recoveries/payables from the sulphide concentrates. Results are pending.


All prices are stated in $USD.


Table 1: Variables considered in the NSR calculations for each concentrate.



Table 2: Base-case Sulphide Mineral Resource Estimate for CLM Project Utilizing a US$60/t NSR cut-off value:


  1. The current Resource Estimate was prepared by Garth Kirkham, P.Geo., of Kirkham Geosystems Ltd.
  2. All 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”).
  3. Mineral resources were constrained using continuous mining units demonstrating reasonable prospects of eventual economic extraction.
  4. Silver Equivalents were calculated from the interpolated block values using relative recoveries and prices between the component metals and silver to determine a final AgEq value. The same methodology was used to calculate the ZnEq value.
  5. Silver Equivalents and NSR$/t values were calculated using average long-term prices of $20/oz. silver, $1,650/oz. gold, $3.25/lb. copper, $1.0/lb. lead and $1.20/lb. zinc. Metal recoveries, payables and deductions are reported in Table 1. All prices are stated in $USD.
  6. Mineral resources are not mineral reserves until they have demonstrated economic viability. Mineral resource estimates do not account for a resource’s mineability, selectivity, mining loss, or dilution.
  7. An Inferred Mineral Resource has a lower level of confidence than that applying to an Indicated Mineral Resource and must not be converted to a Mineral Reserve. It is reasonably expected that the majority of Inferred Mineral Resources could be upgraded to Indicated Mineral Resources with continued exploration.
  8. All figures are rounded to reflect the relative accuracy of the estimate and therefore numbers may not appear to add precisely.

Model Parameters for the Bocona/North Felsite and North Felsite HW Zones

  • The estimate was carried out using separate block models constrained by 3D wireframes of the individual mineralized zones. The block model is comprised of an array of blocks measuring 10m x 1m x 10m which are sub-blocked to 1m x 1m x 1m, with grades for Ag, Au, Cu, Pb and Zn interpolated using Ordinary Kriging within the Bocona/North Felsite zone and Inverse Distance to the Second Power (ID2) weighting for the North Felsite Hangingwall zones. NSR/t, silver equivalent and zinc equivalent values were subsequently calculated from the interpolated block grades.
  • The interpolation was carried out in two passes using progressively larger search radii along strike and down dip of 60m x 60m to a maximum of 100m x 100m. Composites were restricted to a minimum of 3 and a maximum of 9 composites, with a maximum of 3 composites from any one drill hole.
  • Bulk densities were based on sample interval measurements taken by Southern field personnel. For each sample interval, sub-samples were taken from each individual length of core and the weighted average for the sample used. Density values were interpolated on a block-by-block basis using an inverse distance to the second power. An average value of 2.85 t/m3 was assigned to blocks that were not interpolated.
  • Silver composite values have been capped in order to remove the effects of potential overestimation due to statistical outliers. The threshold chosen was 700 g/t silver for the Bocona/North Felsite and North Felsite HW zones. In addition, outlier values for the co-product metals were capped at the threshold levels of 1.5 g/t gold, 2% copper, 18% lead and 10% zinc at Bocona/North Felsite and 2 g/t gold, 0.2% copper, 3% lead and 5% zinc for the North Felsite HW zones, respectively.
  • The mineralized zones were initially defined by Southern personnel and subsequently adjusted and redefined, validated and verified by KGL. The mineralized wire frames were defined using a combination of geological constraints and grade boundaries in addition to consideration of potential reasonable mining thickness. Intervals that were not sampled were assigned a zero grade.
  • For all zones, blocks are classified as Inferred if they are included within 100m of at least one drill hole intercept. Blocks within 40m of the nearest intercept, and estimated by at least two drill holes were classified as Indicated. However, an interpreted boundary is the final determination of indicated and inferred resources in order to remove outlier blocks and the “spotted dog” effect. In addition, continuous potentially underground mining panels were created to demonstrate “reasonable prospect of eventual economic extraction”.


Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. Inferred Resources are considered too speculative geologically to have economic considerations applied to them that would enable them to be classified as Mineral Reserves. An Inferred Mineral Resource has a lower level of confidence than that applying to an Indicated Mineral Resource and must not be converted to a Mineral Reserve. It is reasonably expected that the majority of Inferred Mineral Resources could be upgraded to Indicated Mineral Resources with continued exploration.


Qualified Persons


The independent Qualified Person for the mineral resource disclosure for the project is Garth Kirkham, P.Geo., Principal, Kirkham Geosystems Ltd., who has reviewed and approved the contents of this release.‎ In accordance with National Instrument 43-101 Standards of Disclosure for Mineral Projects, Robert Macdonald, P.Geo, Vice President Exploration, is the Qualified Person for the Company and has validated and approved the technical and scientific content of this news release.


Risk Factors


Southern Silver is aware this project is subject to the same types of risks that large precious and base metal projects experience at an early stage of development in Mexico. The Company has engaged experienced management and specialized consultants to identify, manage and mitigate those risks. However, the types of risks will change as the project evolves and more information becomes available.


About Southern Silver Exploration Corp.


Southern Silver Exploration Corp. is an exploration and development company with a focus on the identification of world-class mineral deposits in major jurisdictions, advancing them either directly or through joint-venture relationships. Our specific emphasis is on advancing the 100% owned Cerro Las Minitas project, one of the world’s largest undeveloped silver-lead-zinc deposits, to a production decision.


Southern has assembled a team of highly experienced technical, operational and transactional professionals to support our efforts in developing (recent robust PEA) the Cerro Las Minitas project into a premier, high-grade, silver-lead-zinc mine. Our property portfolio also includes the Oro porphyry copper-gold project and the Hermanas gold-silver vein project where permitting applications for a drilling is underway; both are located in southern New Mexico, USA.








Posted March 23, 2023

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