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Exploration &

Midwest Project

The Midwest project, owned 25.17% by Denison, 69.16% by ARC and 5.67% by OURD, is host to two significant uranium deposits: the Midwest deposit, discovered in 1978; and the Midwest A deposit, which was discovered in 2004/2005 as well as a number of other significant mineralized zones.

Midwest is located approximately 15 kilometres from the McClean Lake mill where the Midwest ore is planned to be processed once in production. The project is conceived as an open pit operation. Development of the project is currently under review.

Access to the Midwest project is by both road and air. Goods are transported to the site by truck over an all--weather road that connects to the provincial highway system. Air transportation is provided through the Points North airstrip approximately 4 kilometres from the project site. The nearest permanent community is Wollaston Post, about 70 kilometres from the property on the other side of Wollaston Lake.

Water for industrial activities is obtained from one of the many lakes that surround the area. Electric power can be accessed from the provincial grid through nearby Points North.

No tailings storage areas are expected to be required at Midwest since it is planned that all Midwest ore will be transported to the McClean Lake mill for processing, with all resulting tailings being disposed of in McClean Lake's licensed TMF (tailings management facility).

Since the completion of the underground test mine at the Midwest deposit in 1988 and 1989, the site has been under an environmental monitoring and site security surveillance program. At present, there is an inactive water treatment plant, two water storage ponds and a core storage area on the site and a dam in the Mink Arm of South McMahon Lake.


The Midwest deposit will be the first to be mined. Various studies since its discovery in 1978 have examined the feasibility of mining by open pit, underground and SABRE methods. Mining by open pit has been selected as the currently preferred method.

Following the significant increase in the price of uranium starting in 2003, exploration resumed in an area about 3 kilometres northeast of the Midwest deposit. This work led to the discovery of the Midwest A deposit as well as a number of other significant mineralized zones.

Geological Setting

The Midwest uranium deposits lie near the eastern margin of the Athabasca Basin in the Churchill Structural Province of the Canadian Shield. The bedrock geology of the area consists of Precambrian gneisses unconformably overlain by flat lying, unmetamorphosed sandstones and conglomerates of the Athabasca Group. The Precambrian basement rocks are Aphebian--aged, are termed the Wollaston Group, and are essentially graphitic pelitic metasediments. These pelitic metasediments form a steeply dipping syncline which trends northeast. The basement surface is marked by a paleoweathered zone with lateritic characteristics referred to as regolith.

The Midwest deposit is sausage--shaped, 215 metres long with two main pods of high--grade mineralization separated by a 50 metre long section of low grade disseminated mineralization. The average width is 80 metres with a maximum of 128 metres. Thickness of the zone averages 10 metres with a maximum of 30 metres. Overall, the deposit is high grade at 5.50% U3O8. Nickel and arsenic average grades are high, at 4.35% and 5.3% respectively.

The Midwest deposit is representative of a typical unconformity type zone, whereby 99.5% of the resources are located at the basement sandstone contact either in the basal conglomerate or in the upper basement unit.

Locally, mineralized lenses occur along steep faults above and below the main unconformity mineralization. These are termed "perched" and "deep basement mineralization" respectively.

The Midwest A deposit is located at a depth of between 175 and 210 metres below the surface. It consists of several sub-parallel high-grade mineralized zones. These zones are surrounded by low-grade remobilized and clay-rich mineralization. The mineralized zones also exhibit structurally controlled roots that extend as much as 70 metres beneath the unconformity.


In December 2005, the project description for the development of the Midwest deposit was submitted to the CNSC, the Environmental Assessment Branch of Saskatchewan Environment and the Canadian Environmental Assessment Agency. This project description contemplated the Midwest deposit being mined by open pit and a further expansion of the McClean Lake mill.

In September 2011, the final version of the Midwest Project Environmental Impact Statement ("EIS") was submitted to provincial and federal governments. The Comprehensive Study Report was drafted by the CNSC and circulated for federal, provincial and aboriginal review. In September 2012, the Midwest EIS was approved.

The project has remained on care and maintenance throughout 2013 and will remain on care and maintenance in 2015.


While the property is small and relatively intensely drilled, there still exists some good exploration potential.

Please see Annual Information Form and Quarterly Exploration and Development Updates and Financial Reports for further information.


Midwest Project


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