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. (TSX: CXB; OTCQX: CXBMF) (the “Firm” or “Calibre”) is happy to supply an replace on the Borosi exploration challenge held beneath an earn-in possibility settlement between Rio Tinto Exploration (LSE:RIO) (“RTX”) (“Rio Tinto”) and Calibre. Calibre controls a 100% curiosity within the Borosi concessions positioned within the prolific Mining Triangle area of northeastern Nicaragua. RTX has the appropriate to earn a 75% curiosity by spending US$45 million over eleven years within the challenge ( see Calibre information launch dated February 24, 2020 ). The Borosi exploration program is being directed by RTX by way of a partnership settlement with Calibre as challenge operator.

Highlights

• 667km² land bundle strategically positioned over the historic Siuna and Rosita gold/copper mining camps
• Host to potential copper and copper-gold porphyry and associated skarn fashion mineralization
• Over $20 million in exploration work accomplished by Calibre over the previous ten years
• Challenge contains Primavera copper-gold porphyry deposit found by Calibre in 2011
• Borosi is comparatively under-explored for bulk tonnage porphyry fashion base and treasured metals techniques
• An preliminary 5,500 metres of diamond drilling deliberate for 2021

Darren Corridor, President and Chief Govt Officer, commented: “We’re excited to launch the 2021 exploration program with our accomplice Rio Tinto. Partnering with Rio Tinto, a worldwide mining trade chief, offers a major alternative to leverage the invention potential of our massive portfolio of base metals properties whereas we proceed to concentrate on rising gold sources inside our 100% owned exploration and working properties in help of our ‘Hub-and-Spoke’ working mannequin.”

2021 Exploration Program

Since coming into the Borosi possibility settlement in February 2020, the RTX staff has performed intensive analysis of exploration knowledge stemming from Calibre’s work over the previous 10 years in addition to Rio’s personal data sources and knowledge archives that return a number of many years. Greater than 50 potential goal areas have been recognized inside the Borosi concessions. 4 of those areas have been prioritized for a primary go drilling marketing campaign totaling 5,500 metres commencing in early Q2 2021. Moreover, an orientation survey has been initiated to characterize the broader geochemical expression surrounding the Primavera copper-gold porphyry deposit found by Calibre in 2011. The outcomes of this work will present an vital benchmark to information future regional reconnaissance work to be carried out beneath the RTX-Calibre Exploration Alliance settlement the businesses additionally entered in early 2020.

The 4 areas focused for first go drill testing have been chosen based mostly on a mix of things that embrace favorable geologic setting, surficial geochemical signature, and geophysical expression. Three of the focused areas are positioned inside 12 km of the city of Siuna and the fourth, Carpatos, is positioned northeast of Rosita. Abstract descriptions of those areas are supplied beneath:

Carpatos

The Carpatos prospect is positioned 25 km northeast of the city of Rosita. The focused space covers a 6 km² geophysical magnetics excessive and coincident copper-molybdenum and distal zinc-lead-gold soil geochemical anomalies which stay open to the south. Enlargement of the soil sampling grid is underway and can proceed in parallel with exploration drilling anticipated to start in April. Roughly 1,500 metres of reconnaissance drilling is deliberate as a primary go take a look at of the Carpatos goal. The Carpatos mineral concession block adjoins Calibre’s 100% owned Japanese Borosi concession block the place Calibre has just lately initiated an exploration and infill drilling program.

Doña Francesca

Doña Francesca is positioned 5 km to the northeast of the city of Siuna. The goal is outlined by a 2 km² copper-gold in soil anomaly and coincident induced polarization (IP) and resistivity geophysical anomalies. Vast spaced reconnaissance drilling accomplished alongside a 3 km development in 2017 yielded considerable proof of porphyry fashion alteration and veining hosted inside porphyry intrusive host rocks. Observations from drill gap NS17-053 included robust potassic alteration and related “A” and “B” fashion quartz-magnetite + chalcopyrite veinlets and geochemically anomalous copper and gold values over a 120m downhole interval. Roughly 1,000 metres of reconnaissance drilling is deliberate as a primary go take a look at of the Doña Francesca goal.

Timbuco

Positioned roughly 3 km north of Doña Francesca , the Timbuco goal space includes a 12 km² copper in soil geochemical anomaly, the biggest within the Borosi challenge concession bundle. Roughly 1,000 metres of reconnaissance drilling is deliberate as a primary go take a look at of the Timbuco goal.

Mina Victoria – Cerro Asa

The Mina Victoria – Cerro Asa targets embody a cluster of gold-copper in soil geochemical anomalies that extends over 8 km² space. Floor trenching accomplished in 2013 intersected anomalous gold and copper values that included 45m averaging 0.40 g/t Au and 0.19% Cu in trench VTR13-001 and 10.2 meters grading 0.70 g/t Au and 0.11% Cu in trench VTR13-021. The mineralization is related to northeast oriented porphyry intrusive dykes which crosscut the native volcanic and sedimentary host sequence. Roughly 2,000 metres of reconnaissance drilling is deliberate as a primary go take a look at of the Mina Victoria and Cerro Asa targets.

Calibre’s Borosi properties host inferred gold-silver and copper-gold mineral sources on the Cerro Aeropuerto skarn and the Primavera copper-gold porphyry deposits.

The Cerro Aeropuerto deposit incorporates gold, silver and inside a system of quartz veins and related alternative skarn + base metals mineralization. The NI 43-101 compliant Inferred Mineral Useful resource estimate for the Cerro Aeropuerto deposit is supplied within the desk beneath:

Cerro Aeropuerto NI 43-101 Inferred Mineral Useful resource (April 11, 2011)

<sup>1. CIM definition requirements had been adopted for the useful resource estimate.
2. The 2011 useful resource fashions used inverse distance squared grade estimation inside a three-dimensional block mannequin with mineralized zones outlined by wireframed solids.
3. A decrease cutoff grade of 0.6 g/t AuEq (gold-equivalent) was used for reporting mineral sources.
4. Gold Equal (AuEq) grades had been calculated utilizing $1,058/oz Au for gold and $16.75/oz Ag for silver, and metallurgical recoveries and web smelter returns are assumed to be 100%.
5. Useful resource Estimates for Cerro Aeropuerto are detailed within the technical report titled ‘NI 43-101 Technical Report and Useful resource Estimation of the Cerro Aeropuerto and La Luna Deposits, Borosi Concessions, Nicaragua’ by Todd McCracken, dated April 11, 2011.
6. The amount and grades of reported inferred sources on this estimation are unsure in nature and there was inadequate exploration to outline these inferred sources as an indicated or measured mineral useful resource. It’s unsure if additional exploration will end in upgrading them to an indicated or measured mineral useful resource class.
7. Numbers might not add precisely as a result of rounding.
8. Mineral Sources that aren’t mineral reserves don’t have demonstrated financial viability.</sup>

Primavera Copper-Gold Porphyry Deposit (“Primavera”)

• The Primavera deposit is characterised by porphyry fashion copper-gold mineralization hosted inside a sequence of diorite porphyry dikes which have intruded a sequence andesitic volcanic rocks. Mineralization happens in each rock varieties and is typical of porphyry deposits. As Nicaragua’s first porphyry fashion copper-gold discovery, Primavera offers good proof for the area’s potential for the invention of latest porphyry fashion copper + gold techniques.
• Along with Primavera, a number of different potential areas have been recognized inside the 20 km² Primavera challenge space, 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 Useful resource estimate for Primavera is supplied within the desk beneath:

Primavera NI 43-101 Open Pit Constrained Inferred Mineral Useful resource (January 31, 2017)

<sup>1. CIM definition requirements had been adopted for the useful resource estimate.
2. The 2016 useful resource fashions used peculiar kriging grade estimation inside a three-dimensional block mannequin with mineralized zones outlined by wireframed solids (HG=excessive grade, LG= low grade, sap=saprolite).
3. A base cutoff grade of 0.5 g/t AuEq was used for reporting mineral sources.
4. Gold Equal (AuEq) grades have been calculated utilizing $1300/oz Au for gold, $2.40/lb for Copper, and $20.00/oz Ag for silver and metallurgical recoveries are assumed to be equal for all metals.
5. The mineral useful resource is constrained used a pit shell generated with cheap mining parameters.
6. Useful resource Estimates for the Primavera challenge are detailed within the NI 43-101 Technical Report titled ‘Primavera Challenge’ by Todd McCracken, dated January 31, 2017.
7. The amount and grade of reported Inferred sources on this estimation are unsure in nature and there was inadequate exploration to outline these Inferred sources as an indicated or measured useful resource. It’s unsure if additional exploration will end in upgrading them to indicated or measure mineral useful resource class.
8. Numbers might not add precisely as a result of rounding.
9. Mineral Sources that aren’t mineral reserves don’t have demonstrated financial viability.</sup>

Link – RTX Earn-in Map

High quality Assurance/High quality Management

Calibre maintains a High quality Assurance/High quality Management (“QA/QC”) program for all its exploration initiatives utilizing trade finest practices. Key components of the QA/QC program embrace verifiable chain of custody for samples, common insertion of licensed reference requirements and blanks, and duplicate test assays. Drill core is halved and shipped in sealed baggage to Bureau Veritas in Managua, Nicaragua, an impartial analytical companies supplier with international certifications for High quality Administration Programs ISO 9001:2008, Environmental Administration: ISO14001 and Security Administration OH SAS 18001 and AS4801. Previous to evaluation, samples are ready at Veritas’ Managua facility after which shipped to its analytical facility in Vancouver, Canada. Gold analyses are routinely carried out by way of hearth assay/AA end strategies. For larger precision of high-grade materials, samples assaying 10 g/t Au or larger are re-assayed by hearth assay with gravimetric end. Analyses for silver and different components of curiosity are carried out by way of Induction Coupled Plasmaspectrometry (“ICP”).

Certified Particular person

The scientific and technical knowledge contained on this information launch has been reviewed and accredited by Mark A. Petersen, P.Geo., VP Exploration, and a Certified Particular person as outlined by NI 43-101.

ON BEHALF OF THE BOARD

“Darren Corridor”

Darren Corridor, Chief Govt Officer

For additional data, please contact:

Ryan King
Vice President, Company Improvement & IR
T: (604) 628-1012
E: calibre@calibremining.com
W: www.calibremining.com

About Calibre Mining Corp.

Calibre Mining is a Canadian-listed gold mining and exploration firm with two 100%-owned working gold mines in Nicaragua. The Firm is concentrated on sustainable working efficiency and a disciplined strategy to development. Because the acquisition of the Limon, Libertad gold mines and Pavon Gold Challenge, Calibre has proceeded to combine its operations right into a ‘Hub-and-Spoke’ working mannequin, whereby the Firm can benefit from dependable infrastructure, favorable transportation prices, and a number of high-grade mill feed sources that may be processed at both Limon or Libertad, which have a mixed 2.7 million tonnes of annual mill throughput capability.

Cautionary Observe Relating to Ahead Wanting Info

This information launch contains sure “forward-looking data” and “forward-looking statements” (collectively “forward-looking statements”) inside the which means of relevant Canadian securities laws. All statements on this information launch that handle occasions or developments that we count on to happen sooner or later are forward-looking statements. Ahead-looking statements are statements that aren’t historic information and are recognized by phrases corresponding to “count on”, “plan”, “anticipate”, “challenge”, “goal”, “potential”, “schedule”, “forecast”, “price range”, “estimate”, “intend” or “consider” and related expressions or their adverse connotations, or that occasions or circumstances “will”, “would”, “might”, “may”, “ought to” or “would possibly” happen Ahead-looking statements essentially contain assumptions, dangers and uncertainties, sure of that are past Calibre’s management. For an inventory of danger elements relevant to the Firm, please consult with Calibre’s annual data kind for the yr ended December 31, 2019, out there on www.sedar.com . This listing isn’t exhaustive of the elements which will have an effect on Calibre’s forward-looking statements.

Calibre’s forward-looking statements are based mostly on the relevant assumptions and elements administration considers cheap as of the date hereof, based mostly on the data out there to administration at such time. Calibre doesn’t assume any obligation to replace forward-looking statements if circumstances or administration’s beliefs, expectations or opinions ought to change aside from as required by relevant securities legal guidelines. There may be no assurance that forward-looking statements will show to be correct, and precise outcomes, efficiency or achievements may differ materially from these expressed in, or implied by, these forward-looking statements. Accordingly, undue reliance shouldn’t be positioned on forward-looking statements.