TWINNED HOLE RETURNS 65% HIGHER VANADIUM GRADE (1.47% V205) OVER 46.5 METRES ON CORNERSTONE METALS' CARLIN VANADIUM PROJECT
Cornerstone Metals Inc. (CCC.V) has provided the results of five holes, DDC18-09 to DDC18-13, of the 20-hole confirmation diamond drilling program on its Carlin vanadium project, Nevada. The Carlin vanadium project is one of the largest, richest primary vanadium deposits in North America (USGS professional paper 1802 Critical Mineral Resources of the United States -- Economic and Environmental Geology and Prospects for Future Supply dated Dec. 18, 2017).
Four of the newly reported holes were infill diamond drill holes. In addition, Cornerstone's diamond drill hole DDC18-09 specifically twinned a Union Carbide rotary hole R111A from 1967 to confirm and compare rotary results (depth, thickness and grade of the high-grade vanadium unit) to diamond drill core results, besides comparing historic with modern analytical techniques. DDC18-09 compared very well with R111A in the depth and thickness of the high-grade vanadium unit. Surprisingly though, the grade encountered in DDC18-09 was 65 per cent higher than in the historic rotary hole R-111A as displayed in the table.
TWIN HOLE COMPARISON Company Hole ID From (m) To (m) Length (m) V2O5 (%) Zn (%) Ag (g/t) Union Carbide R-111A 7.62 56.39 48.77 0.89 0.22 N/A Cornerstone Metals DDC18-09 10.00 56.50 46.50 1.47 0.33 7.5
"Many of our verification holes within the confines of the historic resource area have returned higher grades than their neighbouring historic holes. Now, with this first twinned hole, there is growing evidence to suggest that historic grades may be understated," said Cornerstone president and chief executive officer Paul Cowley.
The Carlin vanadium deposit has a historic inferred mineral resource estimate of 28 million tons at 0.515 per cent vanadium pentoxide (V2O5), having a total metal content of 289 million pounds V2O5, defined by Dr. Bart Stryhas of SRK in 2010. The estimate was based on a 0.3 per cent V2O5 cut-off grade with the reasonable potential for economic extraction under a conceptual open-pit mining and milling scenario and defined by 127 rotary holes completed by Union Carbide in the late 1960s. V2O5 grades were estimated using an inverse weighting to the second power. The results of the 2010 resource estimation provided a CIM classified inferred mineral resource. The quality of the historical data was good and the mineral resource was classified as inferred mainly due to the fact that the rotary drilling had not been verified by a modern program. The historical estimate does not include any recent data available to the company. The company is not treating this historical estimate as current mineral resources and as such, should not be relied upon. The work needed to upgrade the historical estimate as current mineral resources is to use current costs and metal prices and include the results from the verification diamond drilling program.
Results in detail
The Carlin vanadium deposit, as it is known to date, covers an area two kilometres long by up to 700 metres wide and can be subdivided into four sectors: the Southern, Central, Northern and Western sectors. The five newly reported holes are all within an area 275 m by 60 m in the Central sector. An updated map has been placed on the company's website to graphically demonstrate the Cornerstone and older drill hole collars, outer limits of the historic resource, and the sectors. The section lines A through C and the first eight confirmation holes were described in the Feb. 28, 2018, news release.
The five newly reported holes align on Section line D of the map. As a way to compare the newly reported DDC18-09 to DDC18-13 results with neighbouring older holes, a 500 m long north-south section line D has been drawn though these holes and other historic holes, with their intercepts listed in the attached table.
All drilling on the property to date has been vertical and the high-grade zone is interpreted to be horizontal, therefore all drill intercepts are considered to be true thickness.
DRILL INTERCEPTS ALONG SECTION D Hole ID From (m) To (m) Length (m) V2O5 (%) Zn (%) Ag (g/t) DDC18-09 10.00 56.50 46.50 1.47 0.33 7.5 R-77 6.10 32.00 25.90 0.54 0.20 N/A DDC18-08 21.00 60.00 45.00 0.84 0.38 6.5 R-76 0.00 10.67 10.67 0.69 0.27 N/A DDC18-12 0.25 15.00 14.75 0.68 0.16 5.8 and 27.00 33.00 5.00 0.36 0.22 1.8 DDC18-11 9.00 58.50 49.50 0.45 0.23 2.8 R-75 4.57 48.77 44.20 1.40 0.41 N/A DDC18-10 21.00 61.50 40.50 0.55 0.20 2.6 R-18 3.05 44.20 41.15 0.69 N/A N/A DDC18-13 3.00 40.00 37.00 1.02 0.38 5.0 R-40 12.19 47.24 35.05 0.70 0.37 N/A R-70 12.19 24.38 12.19 0.80 0.34 N/A DDC18-06 15.60 34.50 18.90 1.07 0.47 7.1 R holes are historic drill holes, DDC18-06 and -08 were previously reported, N/A is not analyzed.
The attached table demonstrates that the Cornerstone drilling favourably supports the neighbouring historic holes with zone continuity in similar width and grade where the zone was expected. This demonstrates a widespread near-surface horizontal high-grade mineralized zone. Holes DDC17-09 and DDC18-13 yielded higher grades than the average intercept in the section line table.
The drilling program was supervised by Paul Cowley, PGeo, president and CEO of the company and qualified person for the program. Drill core recoveries averaged 85 per cent. Industry standard quality control and quality assurance protocols have been followed in handling, sampling and shipping the core. The core has been photographed, geotechnically logged and geologically logged. Extensive specific gravity measurements have been taken on the core to aid in a future mineral resource estimation. The core has been cut in half, with one-half sent for analysis and the other half stored as witness core in a secure dry facility in Elko, Nev. Samples have been sent for analyses to MS Analytical, an ISO 17025-accredited laboratory.
Vanadium's growing importance
Vanadium is growing in importance for key industrial manufacturing sectors most notably steel and renewable energy. Today, more than 85 per cent of the world's vanadium is used in steel manufacturing applications. Its importance to the energy sector is also growing rapidly with more than 10 per cent of vanadium production used in energy storage where its substantial cost and performance benefits make it an alternative choice to lithium ion in several areas. Vanadium pentoxide flake prices has risen over the last 2.5 years from under $3 (U.S.) per pound to $15.40 (U.S.)/lb today.
About Cornerstone Metals Inc.
Cornerstone's objective is to advance exploration/development-stage copper, precious and strategic minerals properties to production in the Americas. The company's management and board core competence is in exploration, permitting, development, construction and operating high-value mining projects.
Cornerstone Metals has an option to earn a 100-per-cent interest in the Carlin vanadium project, located in Elko county 22 km by road (14 miles) from the town of Carlin, Nev. The project comprises 72 contiguous unpatented mineral claims totalling 461 hectares (1,140 acres).