Property: 14 Claims totaling 5,188ha
Location: 15km 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
2013 Exploration: Completed 11,448m of drilling in 29 holes, 208km airborne surveying, 69 line km of IP surveying, 101km ground magnetic surveying, 10˛km of geological mapping and collected 1,572 soil samples.
Inferred Resource: 142.3 million tonnes averaging 0.22% copper and 0.26 g/t gold.
Work by Colorado
- Initial exploration over the North ROK claims focused on the "Klappan-Rose" copper showings where felsic dykes and associated skarn-style mineralization returned significant copper and gold values over limited widths. In the 1970's exploration on the current claims focused on the Edon stock where a large malachite stain was noted and numerous disseminated, fracture and quartz vein to stockwork hosted pyrite-chalcopyrite + molybdenite occurrences were discovered associated with propyllitic to phyllic alteration. Since the mid 1980's, exploration work in the area has focused on the ROK-Coyote system to the immediate east and south of the North RoK property.
- In late 2009, Brett Resources Inc. staked the North ROK claim group and in 2010, carried out a reconnaissance program over the claims to test for possible extensions of the ROK Coyote copper-gold system to the north, west and east. The nine day program included silt sampling of creek drainages, prospecting and rock sampling of colour anomalies and known copper showings and occurrences and systematic rock chip sampling along elevation contour lines over the Edon stock and across the Plateau Minfile occurrence.
- Silt samples coming from Mabon Creek and drainages off the northern end of the ridge east of Mabon Creek yielded elevated and anomalous copper, gold and molybdenum values. Rock grabs taken from phyllic altered andesites at the Mabon showing returned elevated and anomalous copper and gold values.
Work by Colorado in 2012 focused on the newly discovered mineralization in the Mabon showing area and included a ground magnetometer survey, an Induced Polarization geophysical survey, soil sampling and detailed prospecting. This work:
- Confirmed the presence of significant copper and gold mineralization, with grab samples returning values up to 3.3 % Cu and 4.4 grams per tonne gold,
- Demonstrated that the quartz-sericite-pyrite alteration is underlain by a 700 long by 350 m wide area of elevated magnetic intensity,
- Defined a 600 long by up to 400 m wide coincident copper and gold anomaly overlying the magnetic anomaly,
- Defined a second 700 m in diameter magnetic anomaly that occurs about 200 m west of the first magnetic anomaly in an area that is totally covered by glacial overburden,
- Demonstrated that the copper and gold mineralization identified in rock and soil is associated with a chargeability anomaly that is 1 kilometre wide and at least 500 metres long and open to the south.
Work by Colorado in 2013 focused on further defining and expanding the Mabon zone mineralization. This work included:
- 69 line kilometres of high resolution 3D Induced Polarization surveying over an 11 kilometre˛ area,
- 101.4 line kilometers of ground magnetometer surveying,
- 1572 soil samples,
- 10 kilometres˛ of geologic mapping,
- The construction of new logging and core storage facilities,
- Receipt of approval from the Ministry of Energy, Mines and Natural Gas to locate up to 50 drill sites,
- 11,448m of drilling in 29 holes.
From this work the company has:
- Determined that the chargeability anomaly that hosts the copper-gold porphyry mineralization at the Mabon Zone measures up to 1300 m wide by at least 2000 m long, and is cored by a zone of high magnetic intensity that is up to 400m wide and 1200 m long,
- Discovered a new chargeability anomaly (the Mabon North Zone) 1 km north of the Mabon discovery drill hole that is 500 to 800 m wide, 1500 m long and is coincident with an irregular magnetic high that is 200 to 500 m wide and 1200 m long,
- Filled in and expanded the copper - gold soil anomalies in the Mabon and Edon Zones,
- Intersected copper - gold porphyry alteration and mineralization over a 900 m strike length, including discovery hole NR13-001 which returned 242 m of 0.632% Cu and 0.85 g/t Au,
- Demonstrated that the copper -- gold porphyry system is open the northwest, southeast and at depth,
- Intersected strong potassic alteration and abundant secondary magnetite on the margin of the large overburden covered magnetic anomaly 300 m west of discovery hole NR13-001.
Inferred Resource Estimate
On January 27, 2014 the company released the results of an inferred mineral 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:
* Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. There is no certainty that all or any part of the Mineral Resources estimated will be converted into Mineral Reserves estimate.
**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:
- US$ 1318.00 per ounce
- US$ 3.25 per pound
The equation to establish Cu Equivalent is then:
CuEq = (Cu% * 71.65) + (Au g/t * 42.37)
The inferred resource estimate was completed by G.H Giroux, M.A.Sc., P.Eng of Giroux Consultants of Vancouver, B.C, Canada an Independent Qualified Person as defined by National Instrument 43-101 Standards of Disclosure for Mineral Projects ("NI-43-101") in accordance with Canadian Institute of Mining, Metallurgy and Petrolium ("CIM") Standards on Mineral Resources and Mineral Reserves adopted by the CIM Council, as amended. Estimation methods are summarized below. Further details of the estimation methods and procedures are available in the NI 43-101 technical report, "NI 43-101 TECHNICAL REPORT ON THE NORTH ROK COPPER-GOLD PROJECT" co-authored by Mr. Mark Rebagliati BSc., P.Eng., an Independent Qualified Person as defined by NI 43-101, filed on SEDAR (www.sedar.com
) and on this website.
Of the 29 drill holes completed to date over a 2 km strike length a total of 18 holes over a strike length of 700 metres with a cumulative length of 7,822 metres intersect the mineralized solid used in the resource estimate. Erratic outliers were capped for both copper and gold. Capped assays were composited over 5 metre intervals honouring the mineralized solid boundaries. The samples were analyzed by Acme Analytical Laboratories of Vancouver, British Columbia. Copper values were first determined using the 1DX ICP-MS method which reports values as parts per million (ppm - 10,000 ppm = 1 %). Any samples containing greater than 2,000 ppm copper were assayed by the 7AR method, which reports values as percent copper. The gold results were determined using the G601 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.
A block model with blocks 10 m x 10 m x 5 m in dimension was created to cover the mineralized solid. Grades for copper and gold were interpolated into blocks containing some percentage of mineralized solid using Ordinary Kriging.
Geologic continuity has been established from surface mapping and drillhole interpretation. This has led to the geologic solid model which constrains the estimate. The grade continuity has been established from the semi-variogram analysis. The semi-variogram orientations and ranges have been used to align and dimension the search ellipsoids, used in the grade interpolation. At this time the density of drilling is too sparse to classify the resource as anything but Inferred.
The 43-101 report recommends a two phase 15,000 m drilling program be conducted at the North ROK property with the first 10,000 m phase intended to delineate the full extent of the North ROK deposit and to test other geological, geochemical and geophysical features including the West Mabon, Edon, Lower Mabon and North Mabon zones. The Colorado technical team is in the process of planning the specific technical and logistical details of the 10,000 m Phase I program.
Mineral 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.