SUDBURY, Ontario, March 02, 2020 (GLOBE NEWSWIRE) -- Rockcliff Metals Corporation (“Rockcliff” or the “Company”) (CSE: RCLF) (FRANKFURT: RO0, WKN: A2H60G) is pleased to provide an updated Mineral Resource Estimate on its 100% owned Tower Property, located in central Manitoba. The Tower Property is part of the Company’s Manitoba property portfolio and is located within the prolific Flin Flon-Snow Lake greenstone belt.
Highlights of the Tower Mineral Resource Update Compared to Previous Resource and Expansion Potential
- Indicated grade increased by 28%;
- Indicated contained metal content increased by 21%;
- Currently drilling 750 metres of strike length from Tower Deposit to highly prospective Tower South Anomaly, not included in this Mineral Resource update
- Tower Deposit remains open along strike and at depth.
Alistair Ross, President and CEO, commented, “This resource update is truly a transformative one as the exceptional high-grade mineralization of the deposit is becoming clearer. The location of the Tower Deposit on a major year-round highway, adjacent to major power lines and easy access to our leased Bucko Mill reduces infrastructure risk for any future mine development scenario. Drilling continues to extend the Tower Deposit southwards where shallow copper mineralization has been identified and is associated with a DPEM conductive that strikes towards the Tower South Anomaly which is located 750 metres south of the deposit. The Tower South Anomaly, an untested anomaly similar in appearance and conductance to the anomaly coincident with the Tower Deposit discovery is the focus of the present drill program. Success of this drilling beyond the limits of the current Mineral Resource Estimate will increase the overall mine making potential of the Tower Property. We are excited to test this area and look forward to releasing our next drill results on a timely basis.”
The Mineral Resource Estimate was prepared by P&E Mining Consultants Inc. (“P&E”). The Mineral Resource Estimate has an effective date of February 27, 2020 is detailed below.
Tower Property Updated Mineral Resource Estimate at 1.5% CuEq cut-off February 28, 2020(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 that 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 Estimation 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 modeling 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 5g/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. In order 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 is 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.
The Technical Report, compiled in accordance with NI 43-101, will be filed on Rockcliff’s issuer profile on SEDAR within 45 days of release of this press release.
Tower Deposit Mineralization and Resource Expansion Potential
The Tower Property hosts the high-grade Tower Deposit, which is defined as a remobilized, single, steeply dipping, high-grade, Volcanogenic Massive Sulphide (VMS) lens that is located immediately below a 100m thick layer of Paleozoic limestone cover. The Tower Deposit consists of stringers and massive sulphide lenses of chalcopyrite, pyrite, pyrrhotite and sphalerite. Drilling has intersected the deposit and the extension mineralization over a strike length of 850m and to a vertical depth of up to 600m. The Tower Deposit remains open along strike and at depth. Geophysical surveys have identified the untested Tower South Anomaly (TSA) approximately 750m south of the Tower Deposit and a conductive corridor between the TSA and the south edge of the Tower Deposit (see Figure 1 below). Within the property limits, the Tower Deposit and the TSA are associated within a 12-kilometre-long arcuate trending magnetic horizon hosting several additional untested conductive geophysical targets considered by the Company to be worthy of follow-up exploration. The depositional environment of the Tower Property is like that of present and past producing VMS deposits and mines associated with bi-model volcanism (felsic to mafic volcanic and volcaniclastic rocks) in the Flin Flon – Snow Lake greenstone belt.
Figure 1: Left Image: Tower Deposit with associated airborne VTEM Tower Anomaly and VTEM Tower South Anomaly (untested). Right Image: Tower Deposit with associated surface VTEM Tower Anomaly and TDEM Tower South Anomaly (untested)
To view an image of Figure 1, please visit:
https://orders.newsfilecorp.com/files/3071/53009_5e9d760484cc2b2b_001full.jpg
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 is 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 are determined by fire assay using a 30g charge followed by an atomic absorption finish. Samples greater than the upper detection limit (3000 ppb) are reanalyzed using fire assay gravimetric using a 1 AT 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 Talbot 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.
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.
For more information, please visit http://rockcliffmetals.com
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For further information, please contact:
Rockcliff Metals Corporation
Alistair Ross
President & CEO
Cell: (249) 806-0387
aross@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.
The Canadian Securities Exchange does not accept responsibility for the adequacy or accuracy of this news release.