19-26 - Bramaderos Main drilling results define areas of higher-grade gold and copper within large porphyry system - Further drilling will aim to extend these higher-grade zones
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: http://www.cornerstoneresources.com/i/pdf/NR19-26Figures.pdf.
HIGHLIGHTS:
Bramaderos Main: Assay results from the complete hole BMDD001, and from the top 200m of BMDD002 have been received.
The results confirm zones of higher-grade gold and copper within a large low-grade gold-copper porphyry system. The geometry of the large gold-copper porphyry system at and near surface correlates strongly with the geometry of the upper-most part of a large plunging and vertically extensive magnetic body.
Early results from trenching and drilling indicate that the higher-grade zones can be mapped at surface and in drill holes as well-defined sub-vertical zones (Figures 1 - 4). At least three of these zones can be seen at surface in the early exploration datasets and trend NW (Figures 1 and 2).
Cornerstone Vice President, Exploration Yvan Crepeau said:
"The drilling results from Bramaderos Main are already outlining higher-grade zones within this large porphyry system. Target areas are becoming clearer as we complete more drilling. We've only drilled 2 holes, but we can already see clear opportunity for a sizeable gold-copper system extending from surface outcrop to at least 300m below surface, and with opportunity to extend laterally by in excess of 500m."
Cornerstone believes Bramaderos Main demonstrates strong potential because:
- Higher grade zones exist and have only been partially drill tested on one cross section to date with BMDD001
- Multiple targets for high grade zones can be defined and will be drill tested. BMDD002 cross section shows the target zone has been drilled and assays are still to come for the bottom 600m of the drill hole
- Highly rated targets are identified on the NE side of the Bramaderos Main prospect and probably trend NW (Figures 1 and 2)
- The higher-grade domains occur within a much larger lower grade gold-copper porphyry system which correlates strongly with the geometry of a large magnetic body
- Improved modelling of magnetics suggests a more sub-vertical system and with considerable vertical extent
- The area below the main Bramaderos Hill, measuring 500m in diameter, is also now emerging as a significant target supported by several datasets
Key intersections from BMDD001 and the top 200m only of BMDD002 are shown below, together with a summary table of trench results that go some way to defining the multiple targets at surface of higher-grade gold and copper areas. Planning is underway for additional trenching in the NW part of Bramaderos Main, and for additional drilling.
| Hole ID | From (m) | To (m) | Interval (m) | Au (g/t) | Ag (g/t) | Cu (%) |
| BMDD001 | 3.45 | 669.5 | 666.0 | 0.26 | 1.06 | 0.10 |
| incl. | 3.45 | 175.4 | 171.95 | 0.52 | 1.79 | 0.16 |
| incl. | 78.8 | 175.4 | 96.6 | 0.61 | 2.08 | 0.18 |
| and | 301.05 | 425.75 | 124.7 | 0.41 | 1.70 | 0.16 |
| incl. | 301.05 | 364.2 | 63.15 | 0.50 | 2.09 | 0.19 |
| and | 458.7 | 535.0 | 76.3 | 0.19 | 0.78 | 0.11 |
| and | 547.4 | 608.7 | 61.3 | 0.14 | 0.85 | 0.10 |
| BMDD002 | 8.44 | 68.65 | 60.21 | 0.18 | 0.82 | 0.10 |
| 68.65 | 199.35* | 130.7* | 0.31 | 1.71 | 0.13 | |
| incl. | 175.65 | 199.35* | 23.7 | 0.35 | 1.85 | 0.17 |
*BMDD002 END OF HOLE depth is 835m. It has been sampled in its entirety, but assay results have only been returned to a depth of 199.35m to date. Complete assays are expected in September.
| Trench ID | Interval (m) | Au (g/t) | Cu (%) |
| BM01 | 105.7 | 0.32 | 0.09 |
| incl. | 59.6 | 0.43 | 0.11 |
| BM02 | 140.6 | 0.57 | 0.15 |
| incl. | 68.2 | 0.8 | 0.18 |
| BM07 | 215.7 | 0.5 | 0.09 |
| incl. | 121.8 | 0.61 | 0.09 |
| BM08 | 105.6 | 0.47 | 0.14 |
| BM14 | 615.14 | 0.52 | 0.11 |
| incl. | 122.6 | 0.55 | 0.17 |
| and | 17.2 | 0.71 | 0.23 |
| and | 97.0 | 0.61 | 0.16 |
| and | 134.9 | 0.5 | 0.07 |
| and | 179.7 | 0.6 | 0.09 |
Limon drilling: LMDD003 was abandoned at 127.33m due to poor ground conditions. Another drill hole will be drilled adjacent to the position of LMDD003. The top of the target zone is between 400m and 500m down hole (Figure 5).
Second drill rig at Bramaderos: A second drilling rig has been engaged for the Bramaderos project and will be mobilized to commence drilling at the West Zone epithermal gold target during August (Figure 5).
The drilling program will comprise at least 5 drill holes for a minimum 1,000m and target interpreted hydrothermal breccia-hosted epithermal gold mineralization that in surface trenching has delivered (see Cornerstone news release dated November 8, 2017):
- 28m at 3.9g/t gold in trench 8
- Including 15.6m at 6.1g/t gold
- 30m at 0.9g/t gold in trench 10
- Including 9.8m at 1.7g/t gold
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 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 in the Cascabel gold-enriched copper porphyry joint venture in north west Ecuador. Exploraciones Novomining S.A. ("ENSA"), an Ecuadorian company owned by SolGold Plc and Cornerstone, holds 100% of the Cascabel concession. Subject to the satisfaction of certain conditions, including SolGold's fully funding the project through to completion of a feasibility study, SolGold will own 85% of the equity of ENSA and Cornerstone will own the remaining 15% of ENSA. SolGold is funding 100% of the exploration at Cascabel and is the operator of the project. SolGold shall receive 90% of Cornerstone's distribution of earnings or dividends from ENSA to which Cornerstone would otherwise be entitled until such time as the amounts so received equal the aggregate amount of expenditures incurred by SolGold that would have otherwise been payable by Cornerstone, plus interest thereon from the dates such expenditures were incurred at a rate per annum equal to LIBOR plus 2 per cent until such time as SolGold is fully reimbursed. In addition, Cornerstone has an indirect interest in the project comprised of 9.2% of the shares of joint venture partner and project operator SolGold Plc, for a total 22.8% direct and indirect interest in Cascabel. 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
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