21:34:29 EDT Thu 15 Apr 2021
Enter Symbol
or Name
USA
CA



Login ID:
Password:
Save
Calibre Mining Corp (2)
Symbol CXB
Shares Issued 333,205,144
Close 2021-04-08 C$ 1.84
Recent Sedar Documents

Calibre, Rio Tinto to drill 5,500 m at Borosi in 2021

2021-04-08 08:10 ET - News Release

Mr. Darren Hall reports

RIO TINTO EXPLORATION AND CALIBRE MINING INITIATE 2021 EXPLORATION PROGRAM INCLUDING 5,500 METRE DRILLING CAMPAIGN PRIORITIZING PROSPECTIVE NEAR-SURFACE COPPER AND COPPER-GOLD MINERALIZATION

Calibre Mining Corp. has provided an update on the Borosi exploration project held under an earn-in option agreement between Rio Tinto Exploration (RTX) and Calibre. Calibre controls a 100-per-cent interest in the Borosi concessions located in the prolific Mining Triangle region of northeastern Nicaragua. RTX has the right to earn a 75-per-cent interest by spending $45-million (U.S.) over 11 years on the project (see Calibre news release dated Feb. 24, 2020). The Borosi exploration program is being directed by RTX through a partnership agreement with Calibre as project operator.

Highlights

  • 667-square-kilometre land package strategically positioned over the historic Siuna and Rosita gold/copper mining camps;
  • Host to prospective copper and copper-gold porphyry and related skarn-style mineralization;
  • Over $20-million in exploration work completed by Calibre over the past 10 years;
  • Project includes Primavera copper-gold porphyry deposit discovered by Calibre in 2011;
  • Borosi is relatively underexplored for bulk tonnage porphyry-style base and precious metals systems;
  • An initial 5,500 metres of diamond drilling planned for 2021.

Darren Hall, president and chief executive officer, commented: "We are excited to launch the 2021 exploration program with our partner Rio Tinto. Partnering with Rio Tinto, a global mining industry leader, provides a significant opportunity to leverage the discovery potential of our large portfolio of base metals properties while we continue to focus on growing gold resources within our 100-per-cent-owned exploration and operating properties in support of our hub-and-spoke operating model."

2021 exploration program

Since entering the Borosi option agreement in February, 2020, the RTX team has conducted extensive evaluation of exploration data stemming from Calibre's work over the past 10 years, as well as Rio's own information sources and data archives that go back several decades. More than 50 prospective target areas have been identified within the Borosi concessions. Four of these areas have been prioritized for a first-pass drilling campaign totalling 5,500 metres commencing in early Q2 2021. Additionally, an orientation survey has been initiated to characterize the broader geochemical expression surrounding the Primavera copper-gold porphyry deposit discovered by Calibre in 2011. The results of this work will provide an important benchmark to guide future regional reconnaissance work to be carried out under the RTX-Calibre exploration alliance agreement the companies also entered in early 2020.

The four areas targeted for first-pass drill testing have been selected based on a combination of factors that include favourable geologic setting, surficial geochemical signature and geophysical expression. Three of the targeted areas are located within 12 km of the town of Siuna and the fourth, Carpatos, is located northeast of Rosita. Summary descriptions of these areas are provided below.

Carpatos

The Carpatos prospect is located 25 km northeast of the town of Rosita. The targeted area covers a six square km geophysical magnetics high and coincident copper-molybdenum and distal zinc-lead-gold soil geochemical anomalies, which remain open to the south. Expansion of the soil sampling grid is under way and will continue in parallel with exploration drilling expected to commence in April. Approximately 1,500 metres of reconnaissance drilling are planned as a first-pass test of the Carpatos target. The Carpatos mineral concession block adjoins Calibre's 100-per-cent-owned Eastern Borosi concession block, where Calibre has recently initiated an exploration and infill drilling program.

Dona Francesca

Dona Francesca is located five km to the northeast of the town of Siuna. The target is defined by a two square km copper-gold-in-soil anomaly and coincident induced polarization (IP) and resistivity geophysical anomalies. Wide-spaced reconnaissance drilling completed along a three km trend in 2017 yielded abundant evidence of porphyry-style alteration and veining hosted within porphyry intrusive host rocks. Observations from drill hole NS17-053 included strong potassic alteration and associated A- and B-style quartz-magnetite-plus-or-minus-chalcopyrite veinlets and geochemically anomalous copper and gold values over a 120 m downhole interval. Approximately 1,000 metres of reconnaissance drilling are planned as a first-pass test of the Dona Francesca target.

Timbuco

Located approximately three km north of Dona Francesca, the Timbuco target area comprises a 12 square km copper-in-soil geochemical anomaly, the largest in the Borosi project concession package. Approximately 1,000 metres of reconnaissance drilling are planned as a first pass test of the Timbuco target.

Mina Victoria -- Cerro Asa

The Mina Victoria -- Cerro Asa targets encompass a cluster of gold-copper-in-soil geochemical anomalies that extend an over eight square km area. Surface trenching completed in 2013 intersected anomalous gold and copper values that included 45 metres averaging 0.40 gram per tonne Au and 0.19 per cent Cu in trench VTR13-001 and 10.2 metres grading 0.70 g/t Au and 0.11 per cent Cu in trench VTR13-021. The mineralization is associated with northeast-oriented porphyry intrusive dikes, which crosscut the local volcanic and sedimentary host sequence. Approximately 2,000 metres of reconnaissance drilling are planned as a first-pass test of the Mina Victoria and Cerro Asa targets.

Calibre's Borosi properties host inferred gold-silver and copper-gold mineral resources at the Cerro Aeropuerto skarn and the Primavera copper-gold porphyry deposits.

The Cerro Aeropuerto deposit contains gold, silver and within a system of quartz veins and associated replacement skarn plus or minus base metals mineralization. The National Instrument 43-101-compliant inferred mineral resource estimate for the Cerro Aeropuerto deposit is provided in the "Cerro Aeropuerto NI 43-101 inferred mineral resource" table.

   CERRO AEROPUERTO NI 43-101 INFERRED MINERAL RESOURCE
                     (April 11, 2011)
 
              Grade      Grade     Contained     Contained
Tonnes      (Au g/t)   (Ag g/t)   Au (ounces)   Ag (ounces)

6,052,000      3.64      16.16       707,750     3,144,500      

1. CIM definition standards were followed for the resource 
   estimate.

2. The 2011 resource models used inverse distance squared 
   grade estimation within a three-dimensional block model 
   with mineralized zones defined by wire framed solids.

3. A lower cut-off grade of 0.6 g/t AuEq (gold equivalent) 
   was used for reporting mineral resources.

4. Gold equivalent (AuEq) grades were calculated using 
   $1,058 per ounce Au for gold and $16.75/oz Ag for silver, 
   and metallurgical recoveries and net smelter returns are 
   assumed to be 100 per cent.

5. Resource estimates for Cerro Aeropuerto are detailed in 
   the technical report titled "NI 43-101 Technical Report 
   and Resource Estimation of the Cerro Aeropuerto and La 
   Luna Deposits, Borosi Concessions, Nicaragua" by Todd 
   McCracken, dated April 11, 2011.

6. The quantity and grades of reported inferred resources 
   in this estimation are uncertain in nature and there has 
   been insufficient exploration to define these inferred 
   resources as an indicated or measured mineral resource. 
   It is uncertain if further exploration will result in 
   upgrading them to an indicated or measured mineral 
   resource category.

7. Numbers may not add exactly due to rounding.

8. Mineral resources that are not mineral reserves do not 
   have demonstrated economic viability.

Primavera copper-gold porphyry deposit

The Primavera deposit is characterized by porphyry-style copper-gold mineralization hosted within a series of diorite porphyry dikes that have intruded a sequence of andesitic volcanic rocks. Mineralization occurs in both rock types and is typical of porphyry deposits. As Nicaragua's first porphyry-style copper-gold discovery, Primavera provides good evidence for the region's potential for the discovery of new porphyry-style copper plus gold systems.

In addition to Primavera, several other prospective areas have been identified within the 20 square km Primavera project area, as demonstrated by anomalous gold and copper in rock and soil samples, magnetic and radiometric geophysical anomalies, and geological mapping.

The NI 43-101-compliant inferred mineral resource estimate for Primavera is provided in the "Primavera NI 43-101 open-pit constrained inferred mineral resource" table.

         PRIMAVERA NI 43-101 OPEN-PIT CONSTRAINED INFERRED MINERAL RESOURCE
                                   (Jan. 31, 2017)
 

               Grade      Grade    Grade     Contained     Contained      Contained
Tonnes       (Au g/t)   (Ag g/t)   (Cu %)   Au (ounces)   Ag (ounces)    Cu (pounds)

27,790,000      0.60       1.22     0.23       535,000     1,094,000    140,070,000     

1. CIM definition standards were followed for the resource estimate.

2. The 2016 resource models used ordinary kriging grade estimation within a 
   three-dimensional block model with mineralized zones defined by wire framed 
   solids (HG is high grade, LG is low grade and sap is saprolite).

3. A base cut-off grade of 0.5 g/t AuEq was used for reporting mineral resources.

4. Gold equivalent (AuEq) grades have been calculated using $1,300/oz Au for gold, 
   $2.40 per pound for copper and $20/oz Ag for silver, and metallurgical recoveries 
   are assumed to be equal for all metals.

5. The mineral resource is constrained used a pit shell generated with reasonable 
   mining parameters.

6. Resource estimates for the Primavera project are detailed in the NI 43-101 technical 
   report titled "Primavera Project" by Todd McCracken, dated Jan. 31, 2017.

7. The quantity and grade of reported inferred resources in this estimation are 
   uncertain in nature and there has been insufficient exploration to define these 
   inferred resources as an indicated or measured resource. It is uncertain if further 
   exploration will result in upgrading them to indicated or measured mineral resource 
   category.

8. Numbers may not add exactly due to rounding.

9. Mineral resources that are not mineral reserves do not have demonstrated economic 
   viability.

Quality assurance/quality control

Calibre maintains a quality assurance/quality control (QA/QC) program for all its exploration projects using industry best practices. Key elements of the QA/QC program include a verifiable chain of custody for samples, regular insertion of certified reference standards and blanks, and duplicate check assays. Drill core is halved and shipped in sealed bags to Bureau Veritas in Managua, Nicaragua, an independent analytical services provider with global certifications for quality management systems ISO 9001:2008, environmental management: ISO 14001 and safety management: OH SAS 18001 and AS4801. Prior to analysis, samples are prepared at Veritas's Managua facility and then shipped to its analytical facility in Vancouver, Canada. Gold analyses are routinely performed via fire assay/AA finish methods. For greater precision of high-grade material, samples assaying 10 g/t Au or higher are reassayed by fire assay with a gravimetric finish. Analyses for silver and other elements of interest are performed via induction coupled plasmaspectrometry (ICP).

Qualified person

The scientific and technical data contained in this news release have been reviewed and approved by Mark A. Petersen, PGeo, vice-president of exploration, and a qualified person as defined by NI 43-101.

About Calibre Mining Corp.

Calibre Mining is a Canadian-listed gold mining and exploration company with two 100-per-cent-owned operating gold mines in Nicaragua. The company is focused on sustainable operating performance and a disciplined approach to growth. Since the acquisition of the Limon and Libertad gold mines and the Pavon gold project, Calibre has proceeded to integrate its operations into a hub-and-spoke operating model, whereby the company can take advantage of reliable infrastructure, favourable transportation costs and multiple high-grade mill feed sources that can be processed at either Limon or Libertad, which have a combined 2.7 million tonnes of annual mill throughput capacity.

We seek Safe Harbor.

© 2021 Canjex Publishing Ltd. All rights reserved.