Calibre Mining increases mineral reserves
Published by Jessica Casey,
Global Mining Review,
Calibre Mining Corp. has announced the results of the company’s updated mineral reserves and mineral resources at its El Limon and La Libertad mining complexes in Nicaragua as of 31 December 2020. Calibre’s 202% increase in mineral reserves supports a strong foundation for a multi-year ‘Hub-and-Spoke’ production and growth strategy. With the largest mineral reserve base in the last 10 years, and the highest reserve grade on record, the company has increased confidence in its ability to generate strong cash flow providing a platform to fund organic growth.
100% owned mineral reserves and mineral resources highlights:
- 202% increase in mineral reserves to 864 000 oz since year-end 2019 and after 2020 depletion.
- Largest mineral reserve since 2010 with the highest grade on record, 4.49 g/t gold (Au).
- 296 000 oz increase in Libertad mineral reserves, from zero at year-end 2019.
- 137% increase in Limon opencast mineral reserves after depletion.
- Total indicated mineral resources of 1 532 000 oz.
- Total inferred mineral resources of 1 314 000 oz.
- New discoveries at Atravesada and Panteon during 2020.
- 60 000 m, exploration and resource growth drilling programme underway.
Darren Hall, President and CEO, stated: “Our investment in exploration in 2020 has resulted in the largest mineral reserve since 2010 and the highest reserve grade of 4.49 g/t Au on record which provides an excellent foundation for future growth. I am very pleased with how the team has integrated our assets utilising our ‘Hub and Spoke’ operating model and positively exceeded production and cost guidance in our first full year of operation.”
“These assets have produced over 5 million oz and yet during 2020 we discovered two new zones at Limon demonstrating the continued upside discovery potential from this long lived and prolific epithermal gold district. With the largest mineral reserve base in a decade and a 60 000 m discovery and resource expansion drilling programme underway, Calibre is well positioned to execute and expand our multi-year ‘Hub-and-Spoke’ operating model including advancing satellite sources like our Eastern Borosi Project in northeastern Nicaragua.”
Priority resource expansion opportunities
- Expansion potential at the Limon underground deposits including Veta Nueva, Atravesada and Panteon.
- Expansion potential along strike and down plunge of the Limon opencast.
- Good potential within the Pavon mineral concessions for new discoveries and resource expansion.
- 60 000 m drilling programme underway at Limon, Libertad, Eastern Borosi and Pavon.
Limon’s total mineral reserves increased 98% since 31 December 2019 to 568 000 oz of gold, net of 2020 production. This was driven by mineral reserves at the Limon opencasts increasing by 137% to 462 000 oz of gold and mineral reserves at Limon underground deposits increasing from 91 000 to 102 000 oz of Au, both net of depletion. Limon opencast mineral reserve grade remained flat while Limon underground mineral reserve grade increased by 12% to 5.14 g/t Au from 4.6 g/t Au on 31 December 2019. Limon’s underground mineral reserve growth was largely driven by two new mineralised shoots at Panteon discovered during the year. Total mineral reserve and resource depletion at Limon during the year amounted to 94 000 oz with the Limon Central pit being the largest contributor.
Infill drilling during the year upgraded inferred mineral resources into the indicated mineral resource category with total indicated mineral resources growing 46% to 1 154 000 oz (inclusive of reserves) with grades increasing by 22% from 2.23 g/t Au to 2.71 g/t Au.
The Limon mineral concessions have historically produced over 3 million oz and continue delivering reliable production with new opportunities for resource discovery and expansion potential. Having discovered the Panteon ore shoots earlier in 2020, the company is excited to announce that the 31 December 2020 resource includes an Atravesada maiden indicated mineral resource of 171 000 t grading 6.20 g/t Au containing 34 000 oz and an inferred mineral resource of 215 000 t grading 6.36 g/t Au containing 44 000 oz. The company expects to grow its mineral resources in 2021 with its multi-rig exploration programme which continues to focus on high-grade resource extensions at Panteon, Atravesada, Veta Nueva and the Limon opencasts.
Mineral reserves at Libertad and Pavon increased from zero on 31 December 2019 to 296 000 oz of gold at a grade of 4.71 g/t Au, net of 2020 production. Jabali underground added 477 000 t grading 3.92 g/t Au containing 60 000 oz of mineral reserves while Jabali opencasts contributed 139 000 t grading 4.25 g/t Au containing 19 000 oz. As recently announced, Pavon added 200 000 open pit oz, 1.28 million t grading 4.86 g/t Au (see news release dated 16 March 2021). Pavon will play an integral role in the ‘Hub-and-Spoke’ model over the coming years with the first ore delivered to Libertad in early 2021. The Pavon project represents a newly emerging gold district in Nicaragua in a region that has remained largely under-explored until now. Two diamond drill rigs are currently testing the potential for lateral and vertical extensions to the Pavon Norte and Central vein systems.
Total indicated mineral resources at Libertad and Pavon increased by 18% from 320 000 to 378 000 oz of gold (inclusive of reserves) as a portion of Jabali underground and Socorro opencast material was upgraded from inferred mineral resources, partially offsetting depletion at the Jabali Antenna opencast. Stockpiles of high-grade ore purchased from artisanal mining collectives added 55 000 t grading 9.3 g/t Au containing 16 000 oz.
The Libertad mineral concessions have produced over 2 million oz historically. Current exploration drilling is testing near mine targets with potential for additional near surface opencast resources. In addition, the company’s field crews continue to identify new areas of prospective gold mineralisation and follow-up drilling on emerging resource growth opportunities at satellite targets such as Amalia located within 35 km of the Libertad mill.
Eastern Borosi Project
Calibre controls a 100% interest in the Eastern Borosi Gold-Silver Property (EBP), located in northeastern Nicaragua. The EBP concession block encompasses a past producing district scale system of near surface epithermal gold-silver veins that hosts inferred resources totalling 4.4 million t averaging 4.9 g/t Au and 80 g/t Ag containing 700 500 oz of gold and 11 359 500 of silver. The project is located approximately 400 km by road from the company’s Libertad Complex, which has approximately 1.5 million tpy of surplus processing capacity, providing a low-cost opportunity for organic growth. Calibre’s interest in EBP grew from 30% to 100% during the year, increasing our attributable inferred ounces over year-end 2019.
Exploration to date at EBP has delineated approximately 20 km of prospective vein structures that occur along three principal northeast trending fault zones. A comprehensive re-interpretation of available exploration data was recently completed to define the broader regional scale controls to mineralisation at EBP. This work has resulted in a new targeting framework that the company’s exploration team is incorporating into its plans for a 7500 m reconnaissance drilling programme which is expected to commence during 2H21.
The company is actively advancing the EBP satellite to be the next potential ‘Spoke’ providing mill feed to the Libertad processing facility. During 2021, Calibre will complete 7500 m of infill, geotechnical and metallurgical drilling to advance EBP to a pre-feasibility study with results expected by this time next year.
Read the article online at: https://www.globalminingreview.com/exploration-development/31032021/calibre-mining-increases-mineral-reserves/
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