Bramaderos Project Update, Ecuador

OTTAWA, March 17, 2021 - Cornerstone Capital Resources Inc. ("Cornerstone" or "the Company") (TSXV-CGP) (F-GWN) (B-GWN) (OTC-CTNXF) is pleased to provide an update on its Bramaderos gold and copper joint venture in southern Ecuador in which it has a 12.5% interest carried by JV partner and project operator Sunstone Metals Inc. (ASX: STM) through to the start of commercial production (see "About Bramaderos", below).

Figures related to this news release can be seen in PDF format by accessing the version of this release on the Company's website (www.cornerstoneresources.com) or by clicking on the link below:

https://cornerstoneresources.com/site/assets/files/5804/nr21-06figures.pdf.

HIGHLIGHTS:

• Two latest holes (ESDD008 and ESDD009) at Espiritu extend the known strike length of the silver-gold mineralization to 700m
  
  
• Drill hole ESDD009 intersected 2 significant lodes of silver-gold-zinc-lead mineralization including:
  
  
  • 2.5m at 65.9g/t silver, 1.63g/t gold from 369.5m
    
    
  • 0.5m at 141g/t silver, 0.28g/t gold, 0.52% copper, 2.73% lead and 1.15% zinc from 370m
    
    
  • 0.6m at 154g/t silver, 6.46g/t gold from 371.4m (only 140m below surface)
    
    
• Detailed soil geochemistry has defined several significant anomalous areas to the south-east for drilling
  
  
• Espiritu is one of several similar targets within the Bramaderos project area
  

Cornerstone VP Exploration, Yvan Crepeau, said:

"These results provide more evidence that Espiritu is a large silver-gold system. It is still early days in the exploration of this system, and we are still developing models for the style and geometry of mineralization, that will in turn enable us to better target the higher-grade areas.

"The early benefits of this approach are seen in drill hole ESDD009, which delivered the highest gold grades we have seen in the system.

"We are seeing the suggestion of groupings of discrete surface anomalies - seen clearly in Figure 3 - that we believe probably reflect higher grade shoots, and which will be the focus of ongoing work. We will be exploring individual targets within an area 700m x 1,500m. Locally these areas contain very high grades of silver and we are getting closer to understanding the controls on those higher grades.

"Once ESDD011 is completed (Figure 2) we will review all data to plan the next phase of drilling. This will include drilling at Espiritu Southeast (Figure 3) where Espiritu style veining is present at surface and corresponds with a cluster of silver-in-soil anomalies over a strike length of 400m. Espiritu is just one of several similar targets within the Bramaderos Project area, which require further exploration."

FURTHER INFORMATION:

Assay results and geological interpretation from holes ESDD008 & 9 show multiple silver-gold bearing structures with various orientations (Figure 1) with local high-grade mineralization (Table 1), including the highest gold grades yet drilled at Espiritu.

Drilling of hole ESDD008 was completed at 359.97m. Drill hole ESDD009 was completed at 451.35m and intersected veins a further 250m south of ESDD008 (Figure 1), now taking the strike extent of the Espiritu silver-gold system to 700m.

Drill Holes ESDD008 and 009 were drilled at shallow angles to surface, and partly following topography, and have only tested to a maximum vertical depth of 140m below surface.

Evidence of multiple lodes continues to be identified in drilling. Narrow high-grade zones appear to narrow and thicken, and better mineralization is interpreted to occur at vein intersections. This is interpreted to generate sub-vertical higher-grade shoots as seen in holes ESDD005 and 006, and to be tested with hole ESDD011 in progress.

Table 1: Details of assay results from holes ESDD008 and ESDD009:

Figure 2 is a cross section showing drill holes ESDD005, 006, and current hole ESDD011.

Figure 3 shows the status of the broader Espiritu target area with infill soil geochemistry highlighting multiple anomalies for follow-up.

Espiritu drill hole locations are shown in Table 2 in the Figures.

About Bramaderos

Measuring 4,948 hectares, the Bramaderos project is located approximately 130km from the Loja provincial capital in southern Ecuador. The project is easily accessible via the Pan American Highway that crosses the property.

The Bramaderos concession is owned by La Plata Minerales S.A. ("PLAMIN"), which in turn is owned 87.5% by Sunstone (the project operator) and 12.5% by Cornerstone. Cornerstone's 12.5% interest is carried by Sunstone through to the start of commercial production and repayable at Libor plus 2% out of 90% of Cornerstone's share of earnings or dividends from the Bramaderos project (see news release 20-01 dated January 7, 2020).

More information about the property can be found at www.cornerstoneresources.com.

Qualified Person:

Yvan Crepeau, MBA, P.Geo., Cornerstone's Vice President, Exploration and a qualified person in accordance with National Instrument 43-101, is responsible for supervising the exploration program at the Bramaderos project for Cornerstone and has reviewed and approved the information contained in this news release.

Sampling and assaying

Surface and drill core samples from Espiritu were sent to the LAC y Asociados Cia. Ltda. Sample Preparation Facility in Cuenca, Ecuador for sample preparation. The standard sample preparation for drill core samples (Code PRP-910) is: Drying the sample, crushing to size fraction 70% <2mm and splitting the sample to a 250g portion by riffle or Boyd rotary splitter. The 250g sample is then pulverised to >85% passing 75 microns and then split into two 50g pulp samples. Then one of the pulp samples was sent to the MS Analytical Laboratory in Vancouver (Unit 1, 20120 102nd Avenue, Langley, BC V1M 4B4, Canada) for gold and base metal analysis.

PLAMIN uses a fire assay gold technique for Au assays (FAS-111) and a four acid multi element technique (IMS-230) for a suite of 48 elements. FAS-111 involves Au by Fire Assay on a 30-gram aliquot, fusion and atomic absorption spectroscopy (AAS) at trace levels. IMS-20 is considered a near total 4 acid technique using a 20g aliquot followed by multi-element analysis by ICP-AES/MS at ultra-trace levels. This analysis technique is considered suitable for this style of mineralization.

Standards, blanks and duplicates are inserted ~1/28 samples. The values of the standards range from low to high grade and are considered appropriate to monitor performance of values near cut-off and near the mean grade of the deposit. The check sampling results are monitored and performance issues are communicated to the laboratory if necessary.

Sample security was managed through sealed individual samples and sealed bags of multiple samples for secure delivery to the laboratory by permanent staff of the joint venture. MS Analytical is an internationally accredited laboratory that has all its internal procedures heavily scrutinized in order to maintain their accreditation. MS Analytical is accredited to ISO/IEC 17025 2005 Accredited Methods.

PLAMIN's sampling techniques and data have been audited multiple times by independent mining consultants during various project assessments. These audits have concluded that the sampling techniques and data management are to industry standards. All historical data has been validated to the best degree possible and migrated into a database.

Rock samples are collected by PLAMIN's personnel, placed in plastic bags, labeled and sealed, and stored in a secure place until delivery by PLAMIN employees to the LAC y Asociados ISO 9001-2008 certified sample preparation facility in Cuenca, Ecuador.

Rock samples are prepared crushing to 70% passing 2 mm (10 mesh), splitting 250 g and pulverizing to 85% passing 75 microns (200 mesh) (MSA code PRP-910). Prepared samples are then shipped to MS Analytical Services (MSA), an ISO 9001-2008 laboratory in Langley, BC, Canada, where samples are assayed for a multi-element suite (MSA code IMS-136, 15.0 g split, Aqua Regia digestion, ICP-AES/MS finish) and gold by Fire Assay (MSA code FAS-111, 30 g fusion, AAS finish). Over limit results for Cu (>1%) are systematically re-assayed (MSA code ICF-6Cu, 0.2 g, 4-acid digestion, ICP-AES finish). Gold is assayed using a 30 g split, Fire Assay (FA) and AAS finish (MSA code FAS 111). Over limit results for Au (>10 g/t) are systematically re-assayed (MSA code FAS-415, FA, 30g., gravimetric finish).

Soil samples are dried at low temperature, screened to 80 mesh (MSA code PRP-757); a 15 grams portion is then assayed for a multi-elements suite (MSA code IMS-136, Aqua Regia digestion, ICP-AES/MS finish).

Quality assurance / Quality control (QA/QC)

The MSA Analytical Laboratory is a qualified assayer that performs and makes available internal assaying controls. Duplicates, certified blanks and standards are systematically used (1 control sample every 20-25 samples) as part of PLAMIN's QA/QC program. Rejects, a 100 g pulp for each rock sample, are stored for future use and controls.

About Cornerstone

Cornerstone Capital Resources Inc. is a mineral exploration company with a diversified portfolio of projects in Ecuador and Chile, including the Cascabel gold-enriched copper porphyry joint venture in northwest Ecuador. Cornerstone has a 21.4% direct and indirect interest in Cascabel comprised of (i) a direct 15% interest in the project financed through to completion of a feasibility study and repayable at Libor plus 2% out of 90% of its share of the earnings or dividends from an operation at Cascabel, plus (ii) an indirect interest comprised of 7.5% of the shares of joint venture partner and project operator SolGold plc Exploraciones Novomining S.A. ("ENSA"), an Ecuadoran company owned by SolGold and Cornerstone, holds 100% of the Cascabel concession. Subject to the satisfaction of certain conditions, including SolGold's fully funding the project through to feasibility, SolGold plc will own 85% of the equity of ENSA and Cornerstone will own the remaining 15% of ENSA.

Further information is available on Cornerstone's website: www.cornerstoneresources.com and on Twitter. For investor, corporate or media inquiries, please contact:

Investor Relations:
Mario Drolet; Email: Mario@mi3.ca; Tel. (514) 904-1333

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Cautionary Notice:
This news release may contain 'Forward-Looking Statements' that involve risks and uncertainties, such as statements of Cornerstone's beliefs, plans, objectives, strategies, intentions and expectations. The words "potential," "anticipate," "forecast," "believe," "estimate," "intend", "trends", "indicate", "expect," "may," "should," "could", "project," "plan," or the negative or other variations of these words and similar expressions are intended to be among the statements that identify 'Forward-Looking Statements.' Although Cornerstone believes that its expectations reflected in these 'Forward-Looking Statements' are reasonable, such statements may involve unknown risks, uncertainties and other factors disclosed in our regulatory filings, viewed on the SEDAR website at www.sedar.com. For us, uncertainties arise from the behaviour of financial and metals markets, predicting natural geological phenomena and from numerous other matters of national, regional, and global scale, including those of an environmental, climatic, natural, political, economic, business, competitive, or regulatory nature. These uncertainties may cause our actual future results to be materially different than those expressed in our Forward-Looking Statements. Although Cornerstone believes the facts and information contained in this news release to be as correct and current as possible, Cornerstone does not warrant or make any representation as to the accuracy, validity or completeness of any facts or information contained herein and these statements should not be relied upon as representing its views after the date of this news release. While Cornerstone anticipates that subsequent events may cause its views to change, it expressly disclaims any obligation to update the Forward-Looking Statements contained herein except where outcomes have varied materially from the original statements.

On Behalf of the Board,
Brooke Macdonald
President and CEO

Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.