Producing Assets Eastern Borosi Gold-Silver


Calibre controls an undivided 100% interest in the Eastern Borosi Gold-Silver Property (the “Property” or “EBP”), located in the northeastern Nicaraguan low-sulphidation, epithermal district that hosts numerous high-grade, gold-silver vein systems. The vein systems hosting the current Inferred Resource of 4,418,000 tonnes at 4.9 g/t Au and 80 g/t Ag containing 700,500 ounces Au and 11,359,000 Ag ounces remain open to further expansion along with numerous undrilled targets. From 2014 to 2020, IAMGOLD Corporation (“IAMGOLD”) spent over US$10 million on the Property in order to earn a 70% interest in the Property. As of August 13, 2020, Calibre restructured the deal with IAMGOLD - see Calibre news release dated August 13, 2020 (click here).

Consideration for IAMGOLD’s 70% interest in the EBP includes (i) 2,253,961 common shares of Calibre (US$3 million), (ii) US$1 million in cash payable 12 months after the date of the acquisition agreement, and (iii) a 2.0% Net Smelter Return royalty (the “NSR Royalty”) on future production from the Property. Calibre has the right to purchase 1.0% of the NSR Royalty for US$2 million and a right of first refusal on the remaining 1.0% NSR Royalty.


  • The 176 km2 EBP hosts NI 43-101 Inferred Mineral Resources containing 700,500 ounces of gold and 11.4 million ounces of silver among six epithermal vein style deposits with a combined 4.4 million tonnes averaging 4.93 g/t Au and 80 g/t Ag (prepared by Roscoe Postle Associates Inc. dated May 11, 2018 with mineral resource summary provided below);
  • Mineral resources have been defined in six vein systems that are exposed along an eight-by-ten kilometre structural corridor that remains open for resource expansion and discovery to the northeast and southwest;
  • The “Mining Triangle” of northeast Nicaragua of which EBP is a part has produced in excess of 8 million ounces1 of gold but remains significantly underexplored;
  • The initial infill and geotechnical drilling program is focused on Guapinol, the adjacent Vancouver, and the Riscos de Oro (“Riscos”) deposits which contain combined inferred resources of 1.97 million tonnes averaging 8.15 g/t Au and 69 g/t Ag containing 515,000 ounces of gold and 4,371,000 ounces of silver;
  • Calibre has made significant progress during Q1, 2021 to acquire surface land rights and commence technical work and baseline environmental studies to support an Environmental Impact Assessment;
  • EBP is located approximately 400 km by road from the Company's 2.2 million tonne per annum Libertad Mill which is currently less than 50% utilized;

Calibre intends to commence exploration drilling in Q3 to test the potential for expanding the Guapinol-Vancouver and Riscos de Oro resources, as well as high priority targets along the principal vein trends at EBP

Following the consolidation of project ownership to a 100% basis in August 2020 (see Calibre news release dated August 20, 2020), the Company initiated a comprehensive evaluation of EBP’s overall exploration and development potential. The work was completed by members of Calibre’s in-house exploration and technical services teams working in collaboration with external exploration and mining consultants. Key outcomes of the evaluation included firstly the recognition of the potential for further development of a high-grade open pit resource at the Guapinol and Vancouver deposits in combination with an underground resource at Riscos de Oro. A second outcome was the recognition of EBP’s significant potential for expansion of currently defined resources in combination with new discoveries on multiple other targets that have so far remained largely untested by exploration drilling.

The current drilling program includes 22,000 metres of infill, geotechnical and metallurgical drilling to support technical studies to evaluate development options for Guapinol-Vancouver and Riscos de Oro. The Company also plans to initiate a 7,500 metre exploration drilling program beginning in Q3 to test the potential to expand resources at Guapinol-Vancouver and Riscos de Oro, as well as first pass testing of high priority gold-silver targets along the principal structural trends in the district. During the past 11 years, a total of 40 kilometres of exploration and resource delineation drilling and 2 kilometres of surface trenching have been completed at EBP.

Strong Resource Expansion Potential

Between 2016 and 2019 drilling on five earlier stage targets intercepted high-grade gold-silver mineralization demonstrating further exploration upside that merits further follow-up. Highlights of previously reported drill results outside of current resources include:

  • Cadillac Zone: 2.6 metres Estimated True Width ("ETW") averaging 8.93 g/t Au and 57.4 g/t Ag between 65.6 and 69.7 metres down-hole in drill hole LS15-008;
  • San Cristobal Zone: 5.7 metres ETW averaging 10.92 g/t Au and 859.0 g/t Ag between 87.8 and 95.9 metres down-hole in drill hole SC18-002;
  • Veta Loca Zone: 5.4 metres ETW averaging 10.15 g/t Au and 6.9 g/t Ag between 88.8 and 94.3 metres down-hole in drill hole GP16-046;
  • La Luna South Zone: 12.7 metres ETW averaging 5.75 g/t Au and 34.3 g/t Ag between 53.0 and 68.9 metres down-hole in drill hole LL18-012.

(see Calibre news releases dated September 15, 2016, February 1, 2018 and December 1, 2018)

To view a PDF of the Eastern Borosi Plan Map, long sections, and location of NI-43-101 Inferred Mineral Resources please go to the following link:

Link 1 - Eastern Borosi Property Maps & Long Sections

Mineral resources have been defined in six vein systems that are exposed along an eight-by-ten kilometre structural trend that remains open to the northeast and southwest.  Calibre intends to (i) evaluate the potential to expand known resources where the vein systems remain open along strike and at depth, (ii) identify and test new vein systems along the structural trend, and (iii) evaluate the opportunity to leverage the resource potential of the Property as part of the Company’s ‘hub-and-spoke’ operating philosophy. Click here to see Deposit Location Map.

Mineral resources have been defined in six vein systems that are exposed along an eight-by-ten kilometre structural trend that remains open to the northeast and southwest.

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