The Puerto Rico project hosts the former Puerto Rico, San José and Zaragoza mines situated along a 12 km long, 1 km wide structural zone. This zone hosts extensive underground workings and prospect pits, with high grade Ag, Zn, Pb and Cu mineralization on surface and in the underground workings that is open for extension in all directions. Very little modern exploration has ever been carried out on what is clearly a district-scale target. There are reported to be over 200 historical workings in the district, with the Puerto Rico and San José mines accounting for over 90% of the historically mined tonnage (1 Mt). Non-mechanized mining by the Vendors at the Puerto Rico project over the past three years, has resulted in the sale of approximately 20,000 tonnes of mineralized material grading > 20% Zn.
Based on exposures in underground workings, the mineralized system hosts multiple high-grade mantos and chimneys separated by lower grade wallrock. To assist with due diligence and in order to verify historical geochemical analyses, the Company arranged for the collection of 33 samples on the Puerto Rico Property during a site visit consisting of: four grab samples from mine dumps or selective samples from outcrops to test specific mineralized zones, six underground grab samples, 10 rock chip samples from outcrops, and 13 underground rock chip samples. Highlights from the sampling include:
- 7% Zn, 4.0% Pb and 180 ppm Ag over 1.0 metre in sample3 A49819;
- 5% Zn, 6.1% Pb and 118 ppm Ag over 1.0 metre in sample3 A49811;
- 0% Zn, 15.7% Pb and 309 ppm Ag in grab sample1,3 A49820; and
- 9% Zn, 12.7% Pb and 299 ppm Ag in grab sample1,3 A49803.
1 Grab samples are selective samples and are not necessarily representative of the mineralization hosted on the property
2 Approximate location
3 Zinc grades quoted are from Zinc oxides
6 mining concessions granted in 2004-2009 for 50 years.
- 5 km south of the US border.
- Vendors are members in the local Ejido.
- Located in “Sustainable Use of Natural Resources” zone, within a Reserve.
- Small scale non-mechanized mining is currently underway by vendors.
- Road access: 242km (3.5 hours) from city of Musquiz (pop: 37,200).
- High Grade, Direct-Shipping Ore
- Commercial production by Kansas City Smelting and Refining (1896-1900)
- ASARCO (1906-1918) mined approximately 1Mt of high grade direct shipping ore (40% Zn).
- Mining on a semi-commercial scale (1970’s to 1985), largely focused on the Puerto Rico and San José Mine areas.
- Over 200 historical workings in the property, with 4,000 metres of underground development.
Current Mining Activity
- Small Scale Semi-Commercial Mining
- The vendors mine > 20% Zn ore using small scale (12 tpd) non-mechanized mining. Sides and backs from the current mining operation are highly mineralized, and are left in place as they grade <20% Zn.
- Over the last 3 years, they have direct-shipped approximately 20,000 tonnes of ore for processing in Monclova, approximately 200km away.
Project Geology & Historical Exploration
- Mineralization hosted along a 12km long, north-northwest fold-thrust corridor.
- Mineralization hosted by Cupido Limestone Formation, Controlled by faults and flexures along the axis of overturned anticline.
- Very limited modern exploration
- Drilling on the property, by the Consejo de Recursos Minerales (“CRM”) and the Metal Mining Agency of Japan (“MMAJ”) during the late 1970’s, was limited to just 16 core holes in the northern section of the property, as land to the south was unavailable. All historical core holes are off target of the main CRD system.
- The CRM and MMAJ undertook geochemical sampling (784 rock chip and soils) and IP & EM on a small area in the north.
- Freeport McMoRan undertook geochemical sampling (63 rock chip and grab samples) on the Puerto Rico and San Jose Mines.
- Independent sampling by SRK for their NI 43-101 Technical Report dated June 12, 2017 yielded the following results from samples taken from the Puerto Rico Mine workings:
Puerto Rico Mine - Chip Samples Independent Verification Samples Collected for Geochemical Analyses
Recent Exploration & Due Diligence
- Recent due diligence work suggests extensive remaining mineralization around historic workings.
- Stacked Ag-Pb-Zn-Cu mantos over a 50 metre width.
- Interstitial wall rock mineralized with galena rich stockworks and massive sulphide replacement of limestone beds.
- Average stope width is reported to be 4 to 10 metres.
Analytical Results of Samples from Puerto Rico Mine (McAnulty, 2009)
Results of Geochemical Samples Collected by Freeport McMoRan in 2008. Samples analysed by ICP and Fire Assay for Silver
Independent sampling for 43-101, property-wide, surface and underground, including host rocks
Maps & Figures