Toronto, Ontario–(Newsfile Corp. – August 11, 2020) – Crown Mining Corp. (TSXV: CWM) (FSE: C73) (“Crown” or the “Company“) is pleased to announce the results of a comprehensive review of historical exploration data on the Company’s flagship Moonlight-Superior Copper Project in Plumas County, California. The review focused on the Superior copper deposit, with the objective of generating drill targets to assess the potential for well-developed high-grade vein and breccia hosted mineralization with silver and gold credits which could improve the overall scope of Moonlight-Superior Copper Project.
- Continuous rock chip-channel samples collected along ribs of underground workings at Superior defined high-grade copper and multi-ounce silver mineralization in broad breccia and vein like structures, including:
- SRW101-111 Zone: 34.1 feet @ 2.57% Cu and 42g/t Ag
- SRW366-367 Zone: 6.2 feet @ 7.33% Cu and 109g/t Ag
- SRW438-441 Zone: 8.5 feet @ 6.13% Cu, 0.07g/t Au and 137g/t Ag
- SRW442-448 Zone: 21.7 feet @ 1.97% Cu and 28g/t Ag
- Historic drilling confirms discrete, but broad zones of high-grade copper mineralization, including:
- S1L-10 – 180 feet @ 0.93% Cu, Including 60 feet @ 1.31% Cu (EOH assayed 6ft @ 0.65% Cu)
- S1L-13 – 114 feet @ 1.46% Cu, Including 36 feet @ 2.27% Cu (EOH assayed 16ft @ 0.88% Cu)
- S1L-16 – 109 feet @ 1.31% Cu, Including 51 feet @ 2.04% Cu (EOH assayed 6ft @ 0.48% Cu)
- Several drill holes terminated in moderate to high grade copper mineralization.
- Previous explorers did not analyze drill core for gold, silver, or molybdenum.
- Grid soil assays define a copper in soil anomaly covering an area of 280-hectares using a threshold of 600ppm copper. Only 70 hectares have been drill-tested.
- There is a general lack of pyrite is in the hydrothermal system.
KEY TAKEAWAYS & CONCLUSIONS
- Broad zones of higher-grade copper – silver and locally gold mineralization have been confirmed in at least ten veins and breccia zones.
- Less than 50% of the copper in soil anomaly has been drill tested at Superior.
- The general absence of pyrite is encouraging, as copper recovery is affected by the proportion and reactivity of pyrite in the ore, and pyrite is an acid forming mineral in waste rock.
- Exploration data review confirms significant potential to expand the resource base at Superior, as mineralization is open at depth and in all directions.
- The Company is designing a drilling program to achieve the following:
- Demonstrate thickness and continuity of high-grade veins and breccia zones.
- Test depth potential and lateral continuity of known mineralization and high-grade zones.
- Scout drill south and west of the current mineral domains, where strong copper in soils occurs.
- Assay all core for a multi-element geochemical suite.
Stephen Dunn, Chief Executive Officer, commented: “Crown has always considered the Moonlight-Superior IOCG and Porphyry Project area as a Tier-1 copper exploration district, and the Team’s analysis of historic data confirms that potential. We are highly encouraged by the findings of this data review, which identifies substantial exploration potential in and around the Superior project area. Exploration data confirms high-grade copper mineralization with associated high-grade silver, which has not been evaluated. Underground rock-chip channel assays show significant silver is associated with the copper mineralization, the implications of this could be significant with respect to the overall project potential.”
DETAILS OF THE DATA REVIEW AT THE MOONLIGHT SUPERIOR COPPER PROJECT
There are three advanced stage copper deposits within the Company’s Moonlight-Superior Copper Project area, known as the Moonlight, Superior and Engels deposits. All three are described in the Company’s “Technical Report and Preliminary Economic Assessment for the Moonlight Deposit” dated April 12, 2018 which is found on the Company’s website.
A detailed review of historic surface and drilling data was undertaken to assess the base and precious metal potential at the Company’s Superior Copper Project, located 3.5km southeast of Moonlight and 3.5km southwest of the Engels copper deposits.
Reported production from the Engels and Superior mines was approximately 160 million pounds of copper, 23,000 ounces of gold and 1.9 million ounces of silver recovered from 4.7 million short tons of ore between 1914 and 1930. Placer Amex explored the property from 1960-1972, drilling over 400 holes and completing significant surface mapping and sampling. There are about 2 million tons of sand tailings about 5000 feet downstream from the historic mill site at Superior.
A 250 feet by 250 feet soil grid covers the project area, with more than 4000 soils collected at Superior. Soils have defined an impressive copper in soil anomaly that covers 280-hectares, contoured using a threshold of 600ppm copper. Within the contours of this 600ppm copper anomaly is a +1200ppm copper anomaly that covers 180-hectares. This anomaly has only been partially explored, with historic drill holes testing only 70-hectares of the 280-hectare copper in soil anomaly.
An aggressive program of underground sampling was undertaken in the old Superior mine from 2007 – 2009, with a total 151 rock chip-channel and select grab samples collected. Mr. Robert Wetzel, a California registered Professional Geologist, oversaw the systematic and continuous sampling along ribs of the underground workings. Rock descriptions indicate mineralization comprises chalcopyrite and bornite, occurring in veins, as coarse blebs and as disseminated grains (Figure 1). Minimal pyrite was observed, but tourmaline, magnetite and specular hematite commonly occur in association with the copper species. The chip-sampling program identified at least ten high-grade vein and breccia-like structures, which historic mining focused on. The high-grade vein and breccia zones are estimated at between 30-100 feet in width, which is based on results of the underground sampling and historic mined stope widths. These high-grade structural zones appear to strike north-south and dip moderate to steeply east, with some veins reported to be sub-horizontal.
Highlights of Wetzel’s channel sampling results are shown in Table 1, which confirm broad zones of high-grade copper and silver mineralization, locally associated with anomalous gold.
Table 1: Superior Project, Significant Assays from 2007-09 Underground Channel Sampling
Notes: Grade intercepts are calculated as a weighted average grade (uncut).
True widths are interpreted to be between 60-90% of the reported lengths, unless otherwise stated.
With respect to drilling, Amex completed 96 diamond drill holes totaling approximately 16,470 meters at the Superior deposit between 1964 and 1967. The most common drill core size that explorers drill and sample in North America today is NQ and HQ sized, however all drilling at Superior was done in BQ size core. BQ core is smaller in diameter (1.43 inches) and hence half core samples provide a sample size less adequate for testing. HQ (2.50 inches) or NQ (1.875 inches) are the preferred core size when drilling out porphyry and IOCG style deposits, a larger core diameter that provides a larger sample size and hence more reliable assay data.
It should be noted that the average hole depth at Superior is only 525 feet (160m) in length, and many holes bottomed in copper mineralization. With respect historic drilling at Superior, all samples were analyzed for copper, but there are very few assays for silver, gold, molybdenum etc. A review of historic drill assays confirms the same style of high-grade copper mineralization was intersected in drill holes, summarized in Table 2.
Figure 1: Recent photos taken along the Level 1 drift. (Left) Strong bornite-chalcopyrite mineralization occurring in cm-scale blebs and in veins, (Middle) Strong malachite stain developed along a broad zone of bornite-chalcopyrite mineralization, (Right) Strong chalcopyrite mineralization occurring in veins and as disseminated grains.
To view an enhanced version of this graphic, please visit:
Table 2: Selected High-Grade Copper Assays from Historic Drill Holes at Superior Project
Notes: Grade intercepts are calculated as a weighted average grade (uncut). NA – Not Assayed
True widths are interpreted to be between 60-90% of the reported lengths, unless otherwise stated.
In addition, the Company announces that incentive stock options to purchase up to 1,600,000 common shares of the Company have been granted to various consultants, officers and directors of the Company pursuant to the Company’s stock option plan and subject to any regulatory approval. Each stock option is exercisable at $0.10 for a period of three years from the grant date. All securities issued pursuant to this option grant will be subject to a four (4) month hold period from the date of grant if exercised with the first four months from the date of grant.
About Crown Mining Corp.
Crown controls approximately 15 square miles of patented and unpatented federal mining claims in the Light’s Creek Copper District in Plumas County, NE California. The District contains substantial copper sulfide and copper oxide resources in three deposits – Moonlight, Superior and Engels, as well as several partially tested and untested exploration targets.
The Superior and Engels Mines operated from about 1915-1930 producing over 161 million pounds of copper from over 4 million tons of rock containing 2.2% copper with silver and gold credits.
The Moonlight PEA, prepared by Tetra Tech Inc., had the following highlights:
- After-tax NPV of US$179M at an 8% discount rate and a $3.15 copper price.
- After tax IRR of 14.6%.
- Initial Capital Cost: US$513M, including a contingency provision in the amount of US$71M.
- Plant Processing Rate: 60,000 tons per day (STPD).
- Average Copper Recovery: 86.0%.
- Mine Life: 17 years, based on the existing Mineral Resource estimate.
- Life of mine copper production of 1.5 billion pounds.
The Moonlight deposit hosts a current National Instrument 43-101 (“NI 43-101”) indicated resource of approximately 170 million tons (154 million tonnes) averaging 0.29% copper, and an inferred resource of 68 million tons (62 million tonnes) averaging 0.29% copper.
The Superior deposit is not included in the Moonlight PEA and it hosts a current NI 43-101 inferred mineral resource of 57 million metric tonnes at an average copper grade of 0.41%. Note no silver or gold were included as part of this resource.
Please note the PEA is preliminary in nature and includes inferred mineral resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves. Furthermore, there is no certainty that the preliminary economic assessment will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability. Readers are encouraged to read the technical report.
Further details of the PEA and the resources on Crown’s property and the parameters used to calculate them can be found in the “Technical Report and Preliminary Economic Assessment for the Moonlight Deposit, Moonlight-Superior Copper Project, California, USA” dated April 12, 2018 on both the company’s website at www.crownminingcorp.com or on www.sedar.com under the Crown Mining Corp. profile.
Mr. George Cole is the Qualified Person pursuant to NI 43-101 responsible for the technical information contained in this news release, and he has reviewed and approved this news release.
For more information please see the Crown website at www.crownminingcorp.com.
For Further Information Contact:
Mr. Stephen Dunn, President, CEO and Director, Crown Mining Corp. (416) 361-2827 or email [email protected].
Cautionary and Forward-Looking Statements
Neither the 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 press release.
This press release contains forward-looking statements within the meaning of applicable Canadian and U.S. securities laws and regulations, including statements regarding the future activities of the Company. Forward-looking statements reflect the current beliefs and expectations of management and are identified by the use of words including “will”, “anticipates”, “expected to”, “plans”, “planned” and other similar words. Actual results may differ significantly. The achievement of the results expressed in forward-looking statements is subject to a number of risks, including those described in the Company’s management discussion and analysis as filed with the Canadian securities regulatory authorities which are available at www.sedar.com. Investors are cautioned not to place undue reliance upon forward-looking statements.
To view the source version of this press release, please visit https://www.newsfilecorp.com/release/61470