Projects

Colorado Creek Property (Gold)

Central Alaska

 

Status and Location - The Colorado Creek project is located approximately 70 km northwest of McGrath, and 410 km northwest of Anchorage in low rolling hills roughly midway between the Kuskokwim and Yukon Rivers.

The Colorado Creek Property (26,880 acres) consists of the following:

  • 5,320 acres (274 claims) of State of Alaska claims owned by Rosander Mining Company. (the "Leased Claims").
  • 21,560 acres of State of Alaska claims originally acquired by NovaGold in June, 2008 after NovaGold's initital review of the property area which indicated new mineralization 2 kilometers further to the southwest beyond the existing claims covered under the Leased Claims from Rosander Mining Company.

The project is located in and around the historical and ongoing placer mining operations at Colorado Creek. Some camp facilities exist on the property and an airstrip serviceable by Hercules aircraft support exploration on the property.

Geology — Rocks in the Colorado Creek project area include the Upper Cretaceous Cripple Creek Mountains (CCM) volcanic-plutonic complex, and a series or slightly younger felsic rhyodacite dikes, all of which intruded the Cretaceous Kuskokwim Group, a thick sequence of shale, greywacke, and minor conglomerate.

Similar to relationships seen at NovaGold Resources Inc.'s Donlin Creek deposit further south, mineralization and geochemical anomalies are associated with the felsic porphyry rhyodacite dikes and sills. These rhyodacite intrusives are distinctive magnetic lows in comparison the volcanoplutonic complexes which are distinctive magnetic highs. Much of the mineralization in the Colorado Creek area is related to dikes and sills in and around the NE-trending Ermine fault zone along the northwest side of the Cripple Creek Mountains.

Known mineral prospects occur along a roughly 7-8 km trend and include Porphyry Knob, Eldorado Creek, Moose Jaw Mountain, Hill 2110, Montana Prospect, and the Wyoming Lode.

Click here to see the Colorado Creek NI 43-101 Technical Report - December, 2010

Exploration Results — 2009 — The Company’s 2009 drilling program at its Colorado Creek, Alaska, property was completed with 2,547 meters drilled in 12 core holes across an area measuring 1.2 kilometers by 0.5 kilometers. The program was designed to test the potential for a major gold mineralized system from a multi-kilometer long area of elevated gold in soil and rock samples. The area of elevated surface gold values is the source area for the extensive Colorado Creek and Cripple Creek placer deposits, estimated to have historic production in excess of 250,000 ounces of gold and still producing. The property lies in the Tintina Gold Belt in southwest interior Alaska and has geologic, geophysical and geochemical characteristics similar to the 30 million ounce gold reserve at the Donlin Creek deposit being developed by NovaGold and Barrick.

 

Project Map — Colorado Creek — Magnetic Map

 

Project Map — Colorado Creek 2009 Drilling

The results from the Company’s first three core holes of its 2009 drilling program at Colorado Creek, Alaska, confirm that gold mineralization is present across significant thicknesses and lateral extent (see attached Map - A1 and A2). Mineralization in these three holes occurs primarily in a rhyodacite quartz porphyry sill which intrudes siltstone, sandstone and andesite, and measures 117.6 meters (~350 feet) thick in DDH CC09-14 (based on the geologic projections, this intersection is believed to approximately represent the true thickness of the sill in this location). These three holes test a gold mineralized area of about 150 m by 470 meters (~450 feet by 1500 feet), and the mineralized rhyodacite remains open to expansion to the south, southwest and southeast.

Gold mineralization in the rhyodacite porphyry is associated with disseminated and veinlet controlled sulfide mineralization. Mineralization has also been observed in both the surrounding sedimentary and volcanic rocks in structurally favorable zones. In addition, drilling further east encountered significant quantities of disseminated sulfide mineralization hosted by altered andesite, diorite, and siltstone proximal to the Cripple granodiorite stock.

Analyses for the next nine drill holes are still pending. Further work could significantly expand the size of the known mineralized body. Additional comprehensive soil sampling and mapping has also been completed over the property as part of this year’s program to determine the extent of the elevated gold target. Of particular interest are large areas of mapped rhyodacite and andesite porphyry units which are known to host mineralization elsewhere in the district.

In the drilling to date, oxidation is pervasive down to approximately 75 meters (~225 feet), but can occur intermittently throughout the entire drilled thickness. Some oxidized veins show visible gold, and visible gold is apparent in drill cuttings and in core saw sludge.

Core samples were split in half and one half was sent to an ALS Chemex facility in Fairbanks, Alaska for preparation into pulps for analysis. Au analyses were done by the ALS Chemex Au-AA23 method which consists of fire assay and an atomic absorption finish.

Historical Exploration — Rosander Mining Company currently mines Colorado Creek for placer gold and historical records indicate that Colorado Creek has produced approximately 52,000 ounces of placer gold, and that Cripple Creek (approximately 2 km west of Colorado Creek) has produced approximately 49,000 ounces of placer gold.

NovaGold Exploration — Prior to Mantra acquiring the project from NovaGold on March 10, 2009, NovaGold had recently conducted exploration on the property after completing the lease agreement with Rosander mining. An initial review of the property had discovered new mineralization 2 kilometers further to the southwest beyond the existing Leaded Claim block resulting in the acquisition by NovaGold of additional claims in June 2008.

Target Type — Tintina based on its review of the project and NovaGold's long term experience feels that Colorado Creek is very analogous to geology and metallogeny exhibited at NovaGold's huge Donlin Creek intrusive related gold deposit.

Future Exploration (2009 — 2010) — The Company upon receipt and analysis of the results from the 2009 exploration program, including drilling results and soil sampling, will desing and conduct the next round of exploration in the spring of 2010.

 

* More information coming soon *