Property Summary: 28 Claims totaling 14,760 hectares
Location: 15 km northwest of Imperial Metals Red Chris Mine Development in NW British Columbia
Owned: 100% by Colorado Resources Ltd
Target: Porphyry copper-gold
Rock Type: Upper Triassic Stuhini Group volcanic rocks intruded by early Jurassic monzonitic rocks
Inferred Resource: 142.3 million tonnes averaging 0.22% copper and 0.26 g/t gold¹
Although considerable exploration has taken place over the years in the area of the North ROK project, the Mabon Minfile occurrence was not identified until 1994 during a regional mapping program conducted by the British Columbia Geological Survey. A single sample taken from the showing during this program returned 0.33 % copper and 0.42 g/t gold.
In late 2009, Brett Resources Inc. staked the North ROK claim group as part of an exploration agreement with Kinross Gold Corp and in 2010 carried out a reconnaissance program over the claims to test for possible extensions of the neighboring ROK Coyote copper-gold system to the north and west. Silt samples coming from Mabon Creek and drainages off the northern end of the ridge east of Mabon Creek yielded anomalous copper, gold and molybdenum values. Rock grabs taken from Mabon showing confirmed the results of the British Columbia Geological Survey sample.
Work by Colorado
Colorado Resources assumed the obligations of the exploration agreement from Brett Resources and subsequently acquired 100 % ownership the North ROK property. In August 2012, Colorado Resources re-evaluated the Mabon showing and has since completed extensive programs of soil sampling, airborne and ground geophysical surveying, geological mapping and diamond drilling.
This work has demonstrated that mineralization at the Mabon Zone occurs within an upper Triassic alkalic porphyry copper-gold system which is predominately hosted in an elongate, 3000 m by 1000 m fine-grained, quartz-deficient plagioclase phyric monzodiorite intrusion called the Mabon Stock. The Mabon Stock and enclosing volcanic rocks are imprinted by a well-defined hydrothermal and contact metamorphic alteration assemblage that zones from high temperature potassic alteration through medium temperature quartz-pyrite alteration to low temperature epidote and chlorite alteration.
Copper-gold mineralization at the Mabon Zone, as disseminated and vein-hosted chalcopyrite, is predominantly associated with the potassic alteration phase and has been demonstrated by diamond drilling to occur over a minimum strike length of 900 m and to extend to a depth of at least 400 m below surface.
The geophysical surveys have demonstrated that the copper-gold mineralization is encompassed by a chargeability anomaly that is up to 1300 m wide and at least 2,000 m long. The chargeability anomaly is cored by a zone of high magnetic intensity that is up to 400 m wide and 1,200 m long.
To date, the Company has completed 13,639.4 m of diamond drilling in 34 holes on the North ROK property. The first hole drilled on the property, NR13-001, intersected 333 m of 0.51 % copper and 0.67 g/t gold. Further highlights from the drilling include 402.2 m of 0.28 % copper and 0.27 g/t gold from NR13-013; 177.1 m of 0.30 % copper and 0.39 g/t gold from NR13-017 and 100.4 m of 0.314% copper and 0.736 g/t gold from NR14-034. Results of all of the drilling to date on the property are shown in the assay results tab. Drill hole locations are shown on the accompanying maps in the maps & sections tab under the North ROK Property. Note that intercept lengths are core lengths and may not be indicative of true thicknesses.
Table of Results
See assay results tab.
Inferred Resource Estimate
On January 27, 2014 the Company released the results of an inferred mineral resource. North ROK Inferred Resource.
Using a 0.20 % Copper Equivalent cut-off the inferred resource* is 142.3 million tonnes averaging 0.22 % copper and 0.26 g/t gold containing 690.30 million pounds of 1.19 million ounces of gold as follows:
**No metallurgical work has been undertaken to establish metal recoveries. For the purpose of developing a copper equivalent and calculating contained metal 100% recovery of both metals is assumed. The reader is cautioned that 100% recovery is never achieved. The metal prices used in the copper equivalent calculation are from a 100 day moving average as of January 27, 2014 and are listed below:
Gold (Au) US$ 1318.00 per ounce
Copper (Cu) US$ 3.25 per pound
|The equation to establish Cu Equivalent is then:|
CuEq = (Cu% * 71.65) + (Au g/t * 42.37)
In May, 2014, the Company completed a 5 hole, 2,191 m drill program on the Property. The 2014 Phase I drill program followed the recommendations of the NI 43-101 report to target the expansion of the known inferred resource and to drill test kilometre scale geophysical anomalies that cluster around the existing inferred resource.
The 2014 Phase I drill program succeeded in:
- Intersecting new mineralization at the West Mabon Zone. DDH NR14–031 was drilled into a 1.5 km long untested IP chargeability anomaly and returned 80.4m of 0.124 g/t gold and 0.442% copper. The Company’s technical team believes that, unlike the sub-vertically dipping North ROK Main Zone, the West Mabon zone has an apparent 45 degree southwest dip (Figure 3). This creates significant exploration potential along the western margins of the IP chargeability over a distance of more than 1.5 km from DDH NR14-034 to the Edon mineral occurrence.
- Demonstrating significant depth potential and continuity of gold-copper mineralization over 250 metres below mineralization in DDH NR13-001. DDH NR14–034 returned 199 m of 0.416 g/t gold and 0.210% copper, including 100.4 m of 0.736 g/t gold and 0.314% copper (Figure 4). Copper – gold grades within selected intervals of both DDH NR14– 034 and DDH NR13–001 approach that which would allow bulk underground mining. These copper-gold mineralized zones are continuing to depths exceeding 400 m below surface.
- Defining the broad, deposit scale geometries and controls on mineralized zones. The presence of a second mineralized zone with a modest southwest dip, when linked to the vertically orientated Mabon Zone, may (i) significantly increase the preferred target area and net tonnage of mineralized rock and (ii) significantly decrease the overall strip ratio of any potential open pit development¹ (See Cautionary Note).
- Extending Mineralization southwest of DDH NR13-013. a modest copper-gold intersection from DDH NR14–032, which cored 38.9 m of 0.265% copper and 0.238 g/t gold between 293.7 and 332.6 m, demonstrates that mineralization extends at least 100 m southwest of DDH 13-013 (160.9 m of 0.41% copper and 0.28 g/t gold) into an area that previous drilling had indicated might be barren.
- Testing of Other Areas. Drill testing of the North Mabon chargeability anomaly (DDH NR14– 030) and tests of the extreme northeastern flank of the Mabon mineralized zone (DDH NR14– 033) produced no significant results.
Southwest Dipping Mineralization Implications - The existence of a southwest dipping mineralized zone in the West Mabon area suggests that the results of drilling in the Edon occurrence area, DDH’s NR13–010, 13–15 and 13–18 may require re-evaluation. All of these drill holes were collared on 220 degree azimuths and drilled at -45 degree dips. These drill holes could have potentially missed southwest dipping mineralization similar to the newly discovered West Mabon Zone. Similarly, DDH NR13–012 which was drilled at an azimuth of 220 degrees and a dip of – 45 degrees would not have been favorably orientated to intersect southwest dipping mineralization like the West Mabon Zone.
The results for the 2014 Phase I drilling program at North ROK are very encouraging and clearly demonstrate that more drilling is required to continue to expand the known inferred resource and to continue to test geophysical anomalies for new areas of mineralization. The Company is currently completing a detailed compilation and analysis of the Phase I results in anticipation for the 2015 field season.
¹Mineral resources that are not mineral reserves do not have demonstrated economic viability. Mineral resource estimates do not account for mineability, selectivity, mining loss and dilution. These mineral resource estimates include inferred mineral resources that are normally considered too speculative geologically to have economic considerations applied to them that would enable them to be categorized as mineral reserves. There is also no certainty that these inferred mineral resources will be converted to measured and indicated categories through further drilling, or into mineral reserves, once economic considerations are applied. The mineral resource estimate referenced above uses the term "Inferred Mineral Resources". "Inferred Mineral Resources" have a great amount of uncertainty as to their existence, and great uncertainty as to their economic and legal feasibility. The SEC normally only permits issuers to report mineralization that does not constitute SEC Industry Guide 7 compliant "reserves" as in-place tonnage and grade without reference to unit measures. U.S. investors are cautioned not to assume that any part or all of mineral deposits in these categories will ever be converted into reserves. Colorado is not an SEC registered company.
The above technical information and all the other technical information on this website pertaining to geology and drill hole data was prepared under the supervision of Colorado's Vice-President of Exploration Greg Dawson, P.Geo. a Qualified Person as defined in National Instruments 43-101 - Standards of Disclosure for Mineral Projects.
The samples were analyzed by Acme Analytical Laboratories of Vancouver, British Columbia. Copper values were first determined using the AQ200 ICP-MS method which reports values as parts per million (ppm). Any samples containing greater than 2,000 ppm copper were assayed by the AQ370 method, which reports values as percent copper. The gold results were determined using the FA430 Fire Assay method which reports gold results in ppm and are equivalent to grams per tonne (g/t). The analytical results were verified with the application of industry standard Quality Control and Quality Assurance (QA-QC) procedures.