Rockcliff Metals Corp. Files Updated Tower Deposit Mineral Resource Estimate
1.03Mt Indicated @ 5.74% CuEq, 0.37Mt Inferred @ 4.29% CuEqSUDBURY, April 16, 2020 - Further to, Rockcliff Metals Corp. (“Rockcliff” or the “Company”) (CSE: RCLF) (FRANKFURT: RO0, WKN: A2H60G) news release dated March 2, 2020, the Company is pleased to announce the filing of a National Instrument 43-101-Standards of Disclosure for Mineral Projects (“NI 43-101”) technical report titled “Technical Report and Updated Mineral Resource Estimate of the Tower Copper (Zinc-Gold-Silver) Project, Manitoba, Canada (the “Technical Report”) in respect of an updated Mineral Resource Estimate prepared by P&E Mining Consultants Inc. (“P&E”) on the Tower Property. The Tower Property is part of the Company’s Manitoba property portfolio and is located within the prolific Flin Flon-Snow Lake greenstone belt. A copy of the Technical Report is available on the Company’s SEDAR issuer profile at www.SEDAR.com and the Company’s website at http://rockcliffmetals.com.
Highlights of the Updated Tower Mineral Resource Estimate Compared to Previous Resource Estimate
- Indicated copper grade increased by 26% (4.69% from 3.73%).
- Indicated gold grade increased by 55% (0.85g/t from 0.55 g/t).
- Indicated zinc grade increased by 26% (1.32% from 1.05%).
- Indicated silver grade increased by 37% (23.7g/t from 17.3g/t).
- Indicated contained copper metal content increased by 19% (106.1Mlbs from 89.2Mlbs).
- Indicated tonnes decreased by 5% (1.03Mt from 1.08Mt).
Alistair Ross, President and CEO commented, “We continue to be pleasantly surprised by the Tower property drilling results. The significant increase in the copper grade to one of the highest grade deposits in the camp at 4.69% Cu bodes well for the PEA analysis. We look forward to receiving the additional drill assay results on holes completed this year since this study was completed.”
The Technical Report prepared by P&E with an effective date of March 2, 2020 is summarized below.
Tower Property Updated Mineral Resource Estimate at 1.5% CuEq cut-off(1-10)
| Classification | Tonnes (k) | Cu (%) | Zn (%) | Au (g/t) | Ag (g/t) | CuEq (%) | Cu (Mlbs) | Zn (Mlbs) | Au (koz) | Ag (koz) | CuEq (Mlbs) |
| Indicated | 1,026 | 4.69 | 1.32 | 0.85 | 23.7 | 5.74 | 106.0 | 29.8 | 28.1 | 783 | 129.8 |
| Inferred | 367 | 3.53 | 1.05 | 0.57 | 18.0 | 4.29 | 28.6 | 8.5 | 6.8 | 212 | 34.7 |
1) Mineral Resources which are not Mineral Reserves do not have demonstrated economic viability. The estimate of Mineral Resources may be materially affected by environmental, permitting, legal, marketing, or other relevant issues.
2) Mineral Resources were estimated using the Canadian Institute of Mining, Metallurgy and Petroleum (CIM), CIM Standards on Mineral Resources and Reserves, Definitions and Guidelines prepared by the CIM Standing Committee on Reserve Definitions and adopted by CIM Council.
(3) The Inferred Mineral Resource in this estimate has a lower level of confidence than that applied to an Indicated Mineral Resource and must not be converted to a Mineral Reserve. It is reasonably expected that the majority of the Inferred Mineral Resource could be upgraded to an Indicated Mineral Resource with continued exploration.
(4) Approximate Jan 31/20 two year trailing average US$ metal prices used were $3/lb Cu, $1.10/lb Zn, $1,350/oz Au and $16.50/oz Ag. The US$: CDN$ exchange rate used was 0.77.
(5) Respective process recoveries for Cu, Zn, Au, Ag were 95%, 80%, 80%, 80%
(6) Respective smelter payables for Cu, Zn, Au, Ag were 96.5%, 85%, 90%, 90%.
(7) Respective USD Cu and Zn smelter treatment charges used were $80 and $250/tonne with concentrate freight of CDN$65/tonne.
(8) CuEq% was calculated as follows: Cu% + (Zn % x 0.220) + (Au g/t x 0.673) + (Ag g/t x 0.008).
(9) The 1.5% CuEq cut-off is approximately equivalent to a C$100/tonne project operating cost.
(10) Contained metal totals may differ due to rounding.
Resource Estimate Methodology
The Mineral Resource Estimate reported herein, considered drilling information available up to December 21, 2019 and was evaluated using a geostatistical block modeling approach constrained by polymetallic mineralization wireframes utilizing Geovia GEMS modelling software. The evaluation of the Mineral Resource Estimate involved CuEq cut-off value determination, cross-sectional polyline interpretation constraining wireframe creation, compositing, grade capping, variography, grade interpolation and Mineral Resource Estimate quantification.
A total of 83 drill holes (totalling 34,665 metres) from the entire database were reviewed and 49 of those drill holes (totalling 18,489 metres) were utilized to create the constraining wireframes which have an overall strike length of 850 metres, down dip projection of 430 metres and average true width of 1.65 metres. There were 313 assays captured by the constraining wireframes that were combined into 147 density weighted composites with an average core length of 1.01 metres. A grade capping evaluation was performed on the composites and gold was capped at 5 g/t, while no capping was required for copper, zinc and silver. The capped composites were evaluated with variography to determine the grade interpolation search ellipsoid ranges for grade interpolation and classification. The Indicated Mineral Resource classification search ranges were 60 metres along strike, 60 metres down dip and 15 metres across dip. For a model block to be coded with an Indicated classification, its centroid must be able to see a minimum of 4 composites from at least 2 drill holes. Grade interpolation was undertaken with the ID2 method for Cu and Zn and ID3 for Au and Ag. The bulk density model was interpreted from 150 bulk density samples with the same method as Cu. The resulting block model utilized blocks that were 2.5 m in the X direction, 5 m in the Y direction and 5 m in the Z direction. The subsequent block model grades and tonnages were quantified for the Mineral Resource Estimate at a 1.5% CuEq cut-off value.
Neither Rockcliff’s Qualified Person, Ken Lapierre, P.Geo., nor P&E’s Qualified Person, Eugene Puritch, P.Eng., nor management of Rockcliff are aware of any known environmental, permitting, legal, title, taxation, socio-political, marketing or other relevant issues that may materially affect the estimate of the Mineral Resource.
Quality Control and Quality Assurance
Samples of half core were packaged and shipped directly from Rockcliff’s core facility in Snow Lake to TSL Laboratories (TSL) in Saskatoon, Saskatchewan. TSL is a Canadian assay laboratory and is accredited under ISO/IEC 17025. Each bagged core sample was dried, crushed to 70% passing 10 mesh and a 250g pulp was pulverized to 95% passing 150 mesh for assaying. A 0.5g cut is taken from each pulp for base metal analyses and leached in a multi-acid (total) digestion and then analyzed for copper, lead, zinc and silver by atomic absorption. Gold concentrations were determined by fire assay using a 30g charge followed by an atomic absorption finish. Samples greater than the upper detection limit (3,000 ppb) were reanalyzed using fire assay gravimetric using a 1 Assay Ton charge. Rockcliff inserted certified blanks and standards in the sample stream to ensure lab integrity. Rockcliff has no relationship with TSL other than TSL being a service provider to the Company.
The Mineral Resource for the Tower Property disclosed in this press release has been estimated by Mr. Yungang Wu, P.Geo. an associate geologist of P&E and Eugene Puritch, P.Eng., president of P&E, both independent of Rockcliff. By virtue of their education and relevant experience Messrs. Wu and Puritch are "Qualified Persons" for the purpose of National Instrument 43-101. Mr. Puritch has read and approved the technical contents of this press release as it pertains to the disclosed Mineral Resource Estimate.
Ken Lapierre P.Geo., VP Exploration of Rockcliff, a Qualified Person in accordance with Canadian regulatory requirements as set out in NI 43-101, has read and approved the scientific and technical information that forms the basis for the disclosure contained in this press release.
Visit Rockcliff’s YouTube channel with a message from the President and CEO, Alistair Ross. To access the video, please visit: https://youtu.be/hXRZZKuYcys.
About Rockcliff Metals Corporation
Rockcliff is a well-funded Canadian resource development and exploration company, with a fully functional +1,000 tpd leased processing and tailings facility as well as several advance-staged, high-grade copper and zinc dominant VMS deposits in the Snow Lake area of central Manitoba. The Company is a major landholder in the Flin Flon-Snow Lake greenstone belt which is home to the largest Paleoproterozoic VMS district in the world, hosting mines and deposits containing copper, zinc, gold and silver. The Company’s extensive portfolio of properties totals over 4,500 square kilometres and includes eight of the highest-grade, undeveloped VMS deposits in the belt.
The Company places the safety and well being of the Company’s workforce as its highest priority. As the COVID-19 pandemic evolves, Rockcliff will continue to monitor the impact of the pandemic as well as Governmental directives and will communicate with all stakeholders accordingly.
For more information, please visit http://rockcliffmetals.com
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For further information, please contact:
Rockcliff Metals Corp.
Alistair Ross
President & CEO
Cell: (249) 805-9020
contact@rockcliffmetals.com
Cautionary Note Regarding Forward-Looking Statements: This news release includes forward-looking statements that are subject to risks and uncertainties. Forward-looking statements involve known and unknown risks, uncertainties, and other factors that could cause the actual results of the Company to be materially different from the historical results or from any future results expressed or implied by such forward-looking statements. All statements contained in this news release, other than statements of historical fact, are to be considered forward-looking. Although Rockcliff believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, such statements are not a guarantee of future performance and actual results or developments may differ materially from those in the forward-looking statements.