Coltstar Ventures Inc. provides an update on its Mackenzie Mountains exploration program. To date, the Company has completed an airborne magnetic survey and a field program over the entire property. Collectively, these exploration activities delineated numerous magnetic anomalies and identified iron formation at the northwestern and southeastern extremities of the property.
The Mackenzie Mountains Project
The Mackenzie Mountains Project is contiguous and adjacent to the Snake River (Crest) iron deposit, the 2nd largest undeveloped iron deposit in the world. The Crest iron deposit has been reported to host a historical resource estimate of 5.6 billion tonnes at 47.2% Fe and a reported “regional resource estimate” of 18.6 billion tonnes (Yukon MIN FILE # 106F 008). Coltstar notes that a qualified person has not done sufficient work to classify Chevron’s historical estimate at Crest as current mineral resources or mineral reserves and Coltstar is not treating this historical estimate as current mineral resources or mineral reserves.
The property covers a 170-kilometre belt underlain by both the Rapitan and Coates Lake Groups.
Airborne Magnetic Survey
During the month of July, Fugro Airborne Surveys flew a helicopter-borne magnetic survey over the Mackenzie Mountains property. The Fugro survey coverage consisted of approximately 4400 line kilometres, at 300-metre line spacing. The purpose of the survey was to detect zones of mineralization and acquire information that could be used to map the geology and structure of the survey area.
The aeromagnetic survey was a complete success. Numerous long magnetic anomalies were delineated. Importantly, the survey outlined two 10 kilometre-long anomalies, extending from drilled iron formation on Chevron’s Snake River (Crest) iron ore deposit immediately onto Coltstar’s ground to the south. From here, an almost continuous magnetic anomaly was delineated over the remaining length of the Mackenzie Mountains property.
Paterson, Grant and Watson (PGW), a firm of consulting geophysicists out of Toronto, conducted a structural and lithological interpretation of the airborne geophysical data acquired by Fugro. Preliminary analysis of the geophysical data led PGW to identify a number of anomalous areas for follow-up or more detailed exploration. These areas were defined on the basis of their higher magnetization relative to the very low background levels of non-magnetic sedimentary units.
These areas were divided into three categories, based on their relative magnetic signatures:
1. 114.6 km2 of iron-rich Rapitan formation, exposed or very close to the surface;
2. 416.9 km2 of iron-rich Rapitan formation, covered by sedimentary rock; and
3. 302.7 km2 of deeply buried iron-rich rocks.
Field Program – Mackenzie Mountains Iron Project
Aurora Geosciences Ltd. conducted a ground exploration program over the Mackenzie Mountains property consisting of geological mapping, ground magnetic and susceptibility measurements and the collection of chip and rock samples.
The goal of the field program, which focused primarily on claims in the immediate vicinity of Chevron’s Crest iron deposit, was to investigate the magnetic anomalies detected by the airborne geophysical survey and to confirm the presence of iron formation in areas mapped as Rapitan Group on Coltstar’s claims.
During the ground exploration program, iron formation was observed in a number of locations on Coltstar’s Mackenzie Mountains property. The field crew observed iron formation outcrops on Coltstar’s property south of Chevron’s Crest property (Zone A). This iron formation unit continues, at a shallow angle, on Coltstar’s property, until it is terminated by a thrust fault several kilometres away. The area of potential iron formation between the outcrop location and the contact with the fault is approximately 9 km2. A Chevron drill hole, located 375 metres north of the iron outcropping on these Coltstar claims, intersected 27.4 metres grading 43.1% soluble iron.
West of Zone A, iron formation exposed in a riverbed on Chevron’s property, is likely to extend, at a shallow angle, onto several of Coltstar’s claims (Zone B). Zones A and B, each 10 kilometres long, are spatially related to the magnetic anomalies delineated by the aeromagnetic survey. For a map, showing the locations of Zones A and B, please see www.coltstarventures.com .
Confirmation of Copper Prospectivity
On the last day of the field program, the geological crew found malachite-stained boulders in a talus field. This observation of malachite, a common oxidation product of copper mineralization, confirms the property’s copper prospectivity. It was not possible to access the likely outcrop source due to the steep terrain. The area where the malachite was observed is coincident with thickening of the Coates Lake Group on the Mackenzie Mountains property. This discovery warrants follow-up given its occurrence in a geological setting, which is similar to that which hosts the Nite, Keele and Coates Lake deposits further to the south.
A ground magnetic survey and measurements of magnetic susceptibility were made during the field program in order to characterize the magnetic signature of various rock units. The results of this work will assist in the modeling of the aeromagnetic results. The primary goal of the modeling is to outline the distribution of the iron formation throughout the property.