Diablillos is a 7,919 ha property located in the Argentine Puna region, which is the southern extension of the Altiplano of southern Peru, Bolivia, and northern Chile. It is a high plateau, separating the Cordillera Oriental to the east from the Andean Cordillera (Cordillera Occidental) to the west. Other major deposits in this region include Taca Taca, Escondida, and Pirquitas.
There are currently seven known mineralized zones on the Diablillos property, with the Oculto zone being the most important and the best explored. Oculto is a high-sulphidation epithermal silver-gold deposit derived from remnant hot springs activity following Tertiary-age local magmatic and volcanic activity with strong supergene overprinting.
Remaining payment of US$7M due to SSR in 2025
|Geology||High-sulphidation epithermal silver-gold deposit|
|Location||Salta Province, Argentina
Approx. 160 km southwest of city of Salta, along border between Provinces of Salta and Catamarca
|Elevation||Between 4,100 to 4,650 MASL|
|Nearby Projects in Salta||Lindero (Fortuna Silver)
Taca Taca (First Quantum)
Rio Grande (Aldebaran)
El Quevar (Golden Minerals)
|Drilling to Date||Approx. 100,000m with expenditures of +US$40 million|
|Stage||Updated PEA expected to be completed in Q4/2021.
All dollar ($) figures are presented in US dollars unless otherwise stated. Base Case metal prices used in this analysis are $1,650 per gold (“Au”) ounce (“oz”) and $24.00 per silver (“Ag”) oz.
PEA Study Highlights:
- Robust Economics:
- Pre-Tax NPV5% of $678.5 Million (CAD$ 882.1 Million) with an Pre-Tax IRR of 44.3% (Base Case);
- After-Tax NPV5% of $364.0 Million (CAD$ 473.2 Million) with an After-Tax IRR of 30.2% (Base Case).
- 7,000 tonnes per day (“tpd”) production rate with an initial mine life of up to 16 years.
- Average annual production:
- Average annual production in first 5 years of 8.0 Moz Ag and 44.3 koz Au, or 11.4 Moz AgEq;
- Average Life-of-Mine (“LOM”) production of 4.2 Moz Ag and 52.0 koz Au, or 8.5 Moz AgEq.
- Low cash operating costs:
- All-in Sustaining Cash Costs (“AISC”) during first 5 years of $10.41/oz AgEq;
- All-in Sustaining Cash Costs (“AISC”) during average Life-of-Mine (“LOM”) of $11.97/oz AgEq.
- Initial Capital Expenditure of $255.0 million, with payback period of 2.6 years.
- Several potential opportunities have been identified that may significantly further enhance the economic returns as detailed later in this release.
Commodity Price Sensitivity Analysis
|Silver Price ($/oz)||$20.40||$24.00||$27.60|
|Gold Price ($/oz)||$1,400||$1,650||$1,900|
|After-tax NPV (5%, US$ million)||$190||$364||$538|
|After-tax NPV (5%, CAD$ million)||$247||$473||$700|
|After-Tax IRR (%)||20%||30%||39%|
1Note: Based on USD/CAD F/X rate of: 1:30 : 1
The PEA was prepared in accordance with National Instrument 43-101 Standards of Disclosure for Mineral Projects (“NI 43-101”). The PEA was led by Mining Plus Peru S.A.C. with contributions from Hanlon Engineering & Associates Inc. (a subsidiary of GR Engineering Services Limited) and SAXUM Engineering LLC locally in Argentina.
Summary of Economic Results
The table below summarizes the key economic results and parameters of the PEA study.
Summary of Project Economics
|Life of mine||years||16|
|Total mineralized material mined||M tonnes||37.4|
|Total contained silver||M oz||86.9|
|Total contained gold||k oz||939.8|
|Strip ratio||Waste : ore||3.6|
|Head grade – silver (first 5 years / LOM)||g/t||130.5 / 72.2|
|Head grade – gold (first 5 years / LOM)||g/t||0.65 / 0.78|
|Recoveries – silver (first 5 years / LOM)||%||77.4 / 73.4|
|Recoveries – gold (first 5 years / LOM)||%||85.9 / 86.0|
|Average Production – silver (first 5 years / LOM)||M oz||8.0 / 4.2|
|Average Production – gold (first 5 years / LOM)||k oz||44.3 / 52.0|
|Operating cash costs LOM – silver equivalent||$/oz AgEq||9.83|
|Operating cash costs LOM – gold equivalent||$/oz AuEq||816|
|AISC (LOM) – silver equivalent (first 5 years / LOM)||$/oz AgEq||10.41 / 11.97|
|AISC (LOM) – gold equivalent (first 5 years / LOM)||$/oz AuEq||818 / 993|
|Initial Capital Costs||$ M||255.0|
|Sustaining Capital Costs||$ M||23.4|
|Pre-Tax NPV5%||$ M||678.5|
|After-Tax NPV5%||$ M||364.0|
The complete NI 43-101 technical report is available here
The Company cautions that the PEA is preliminary in nature and is intended to provide an initial, high-level review of the project’s economic potential. The PEA replaces and supersedes the Company's previous 2018 PEA study. There is no certainty that the results of the PEA will be realized. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
Oculto Mineral Resource Estimate – As of September 8, 2021
(000 oz Ag)
(000 oz Au)
|Measured & Indicated||37,294||70||0.71||84,139||848|
|Measured & Indicated||3,899||48||1.23||6,026||155|
|Measured & Indicated||41,193||68||0.76||90,165||1,002|
- Mineral Resources are not Mineral Reserves and have not demonstrated economic viability.
- The MRE has been categorized in accordance with the CIM Definition Standards (CIM, 2014).
- All figures are rounded to reflect the relative accuracy of the estimates. Minor discrepancies may occur due to rounding to appropriate significant figures.
- The Mineral Resource was estimated by Ms Muñoz QP(Geo), Independent Qualified Person under NI 43-101., of Mining Plus Consultants who takes responsibility for it.
- The Mineral Resource is sub-horizontal with sub-vertical feeder with a reasonable prospect for eventual economic extraction by open pit methods with a 3.67 strip ratio.
- The Mineral Resource is reported inside a whittle pit shell with a cut-off grade of 35 g/t silver equivalent, estimated using a gold price of US $1750 and silver price of US $25.
- The silver equivalent is based in the following formula AgEq = Ag + Au*70.
- The resource models used ordinary kriging (OK) grade estimation within a three-dimensional block model with mineralized zones defined by wireframed solids and constrained by Whittle pits shell, the 2m composite grades were capped where appropriate.
- All tonnages reported are dry metric tonnes and ounces of contained gold are troy ounces.
- Bulk density was assigned to the block model as averages of the oxidation zone subset by alteration.
- Average bulk density for the Oxides is 2.18 t/m3 for the M&I category and 2.14 t/m3 for the Inferred category.
- Average bulk density for the Transition Zone is 2.41 t/m3 for the M&I and Inferred category.
- Average bulk density is 1.82 t/m3 for cover material, and 2.15 t/m3 for waste material.
- Mining Plus is not aware of any environmental, permitting, legal, title, taxation, sociopolitical, marketing, or other relevant issues that could materially affect the potential development of the Mineral Resource Estimate.
Mineral Resources at the Diablillos Project are considered as potentially mineable by an open pit method and are estimated based on drilling conducted prior to AbraSilver and more recent drilling done by the Company between 2019 - 2021. The Mineral Resource includes an updated Resource for the Oculto deposit. The Mineral Resource is reported inside a Whittle pit shell with a reasonable cutoff grade of 35 g/t silver equivalent, based on a gold price of US$1750/oz and silver price of US$25/oz, mining costs and metallurgical recovery from the previous studies.
The Mineral Resource is summarized as at September 8, 2021 and has been estimated in alignment with the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Estimation of Mineral Resource and Mineral Reserves Best Practices Guidelines (CIM, 2019) and the Mineral Resource Estimate has been categorized in accordance with the CIM Definition Standards (CIM, 2014) and comprises a Measured, Indicated and Inferred Mineral Resource.
Mineral Resource Estimate Sensitivity
Cut-Off Grade Sensitivity of Measured & Indicated Mineral Resources
The Mineral Resources Estimate were estimated by Ms. Maria Muñoz, MAIG QP(Geo). Ms. Muñoz is a full-time employee of Mining Plus Peru SAC and is an independent Qualified Person ("QP") as defined by the National Instrument 43-101. The Mineral Resources have been classified in accordance with CIM Definition Standards for Mineral Resources and Mineral Reserves.
AbraSilver has completed the very successful Phase I exploration program, consisting of approximately 15,000 metres on the Oculto deposit. The Company intersected multiple high-grade zones of silver, gold and copper and successfully achieved all three of its top priorities with the drill program, namely:
- Identify additional gold resources in the deeper oxide gold zone;
- Extend silver-gold mineralization northeast of the Whittle Pit boundary;
- Define a shallow gold zone (from surface to ~100m depth) which would benefit early open pit mining operations.
In total, the Phase I drill program had a high-grade hit rate of approximately 90% of the drill holes intersecting high-grade mineralization over significant widths. See the detailed Drill Results Table for Phase I here. The program, included several world-class drill intercepts including:
The Company is currently conducting its Phase II exploration program, which will consist of a minimum of 10,000 metres of diamond drilling. The Phase II drill program will focus on the following priority targets:
- Oculto Northeast extension: Several previous drill holes in the Oculto Northeast zone intersected substantial gold values, which are not included in the current resource. It is expected that the Whittle Pit on the main Oculto deposit could be expanded in this direction to incorporate additional high-grade resources.
- Laderas Zone: The Laderas Zone is located approximately 500 metres north of Oculto deposit on the Diablilllos property. Previous shallow drilling at Laderas intersected significant gold and copper intercepts over broad widths.
- The Northern Arc: The Northern Arc contains a cluster of prospects that lies approximately three to four kilometres north-northeast of the centre of the Oculto deposit. All have near surface, high grade gold intercepts in epithermal mineralisation similar in style to Oculto, with potential for shallow resources that could be trucked to a future treatment plant at Oculto. The Cerro Viejo area shows potential for porphyry mineralization.
The Diablillos property hosts several zones of high-sulphidation epithermal alteration and mineralization with strong supergene overprinting. There are several known mineralized zones on the Diablillos property, with the Oculto zone being the principal deposit. Oculto is strongly oxidized down to depths in the order of 300 m to 400 m below surface. The precious metal mineralization throughout the deposit occurs as extremely fine grains along fractures and in breccias or coating the inside of vugs and weathered cavities.
Gold and silver mineralization ascended along steeply dipping feeder structures and was deposited in siliceous breccia zones. Mineralizing fluids also migrated laterally along shallowly dipping favourable permeability horizons where it was deposited along with silicification. Gold is associated with a deeper permeability horizon and with shallow zones associated with the feeder structures, while there is a secondary enriched silver zone related to a weathering horizon. Both steeply dipping and shallowly dipping zones were taken into account in the new resource estimate.
Over US$50 million has been spent on exploration at Diablillos totaling over 100,000 meters of drilling in over 450 holes.
|1983||Secretaría de Minería de la Nación||1,409 rock chip samples (includes 190 outcrop and 271 slope debris samples from Diablillos Sur)|
|1984 - 1987||Shell C.A.R.S||A Rock geochemical survey; three Winkie drill holes|
|1987||Ophir Partnership||37 rotary drill holes (approximately 30 m deep) in the Corderos, Pedernales, Laderas, and Jasperoide areas|
|1989 - 1991||BHP||Geological mapping (1:1,000 to 1:7,500 scale); 380 rock chip samples; 1,200 m of bulldozer trenches; 55 air RC holes (6,833 m)|
|1993||Pacific Rim Mining Corporation||Five diamond drill holes (1,001.8 m) in the Oculto Zone|
|1994||Pacific Rim Mining Corporation||148 km of chain and compass grid; geological mapping; 122 line-km of ground magnetic survey; 34 line-km of induced polarization (IP) survey; 213 hand auger samples; 2.5 km of trenching; 250+ rock chip samples; 12 diamond drill holes (2,013.9 m)|
|1996 - 1997||Barrick Gold Corp||Geological mapping; surface sampling; RC drilling; CSAMT survey; mag survey; environmental impact study; metallurgical test work|
|2003||Pacific Rim Mining Corporation
(for Silver Standard)
|20 diamond drill holes (3,046 m)|
|2005||Pacific Rim Mining Corporation
(for Silver Standard)
|Five diamond drill holes each at Renacuajo and Alpaca|
|2007||Pacific Rim Mining Corporation
(for Silver Standard)
|45 diamond drill holes (9,600 m) on Oculto; one hole (203 m) at Laderos; three holes (unknown length) at Pedernales; five holes (unknown length) at Los Corderos; four HQ-size diamond drill holes sampled for metallurgical tests|
|2008||Pacific Rim Mining Corporation
(for Silver Standard)
|52 diamond drill holes (7,910 m), three of these for geotechnical studies; additional metallurgical studies|
|2009||Silver Standard Resources||Mineral Resource estimate|
|2011 - 2012||Silver Standard Resources||Internal Preliminary Economic Assessment, rock chip sampling, 1,679 m diamond drilling (19 holes)|
|2017||AbraSilver||28 drillholes and a total of 3,148.5m|
|2018||AbraSilver||Preliminary Economic Asessment including Resource estimate|
|2019||AbraSilver||Phase I Drilling Campaign with 2 diamond drill holes (844 m),|
|2020 - 2021||AbraSilver||Phase II Drilling Campaign of 55 drillholes and a total of 15,143 m expanding Oculto to North, West and East and testing new targets|