Denison Mines Inc.

Denison Mines Inc.

October 28, 2005 07:30 ET

Denison Outlines Uranium Exploration Plans

TORONTO, ONTARIO--(CCNMatthews - Oct. 28, 2005) - Denison Mines Inc. (TSX:DEN) is pleased to provide an update to its extensive, on-going, uranium exploration activities on its five projects in the Athabasca Basin in northern Saskatchewan. Denison's share of exploration expenditures in 2005 is projected to be in excess of $3.5 million and, although formal approval of the various exploration budgets will not be completed until mid-November, are planned to be increased to about $5.0 million in 2006.

All of Denison's exploration projects are concentrated along the prolific southeast margin of the Athabasca Basin near the major uranium operations of McArthur River, McClean Lake and Cigar Lake. Four projects are adjacent or within a relatively few kilometres of the McClean Mill, owned 22.5% by the Company, and the fifth, Wheeler River, is within 35 kilometres of the Key Lake Mill. This proximity to existing, licensed, operating mills is a very distinct benefit which would allow any discovery to be rapidly placed into production without the need for the time consuming regulatory process required for the construction of a new mill.

All uraniferous distances and intersections reported in this release are downhole lengths and may not represent true widths.


Exploration activities during last winter, on the 25.17% owned Midwest Project, targeted an area three kilometres north of the main reserves as a follow-up to the early 1980s drill hole MW-338 which intersected 8.24% U3O8 over 3.8 metres at the unconformity.

As previously reported, two of three angle holes drilled last winter on a section 60 metres southwest and on strike of drill hole MW-338 intersected significant unconformity-related uranium mineralization. Another hole, drilled along section with MW-338 and designed to intersect the unconformity 25 metres northwest of the known mineralization also intersected significant high-grade mineralization. The winter program was cut short by very poor ice conditions.

Hole No. From (m) To (m) Intersection (m) Grade (e U3O8 %)

MW-659 229.20 236.30 7.10 6.25
MW-660 197.40 205.10 7.70 11.67
MW-662 215.70 233.40 17.70 1.14

A delineation drill program of at least 5,000 metres is planned for 2006 to follow up on the encouraging results obtained last winter to define the limits of this mineralization.

Another focus of the Midwest program in 2006 will include the drilling of a number of holes under the main deposit to test for basement hosted mineralization. During the drilling campaigns in the late 1970s and early 1980s, mineralization was intersected in the basement at a depth of about 100 metres below the unconformity, but, since the target during the previous campaigns was only unconformity hosted mineralization, this basement mineralization was not followed up. The potential for basement hosted style mineralization is a high priority target, not only under the Midwest high-grade reserves, but also under the four kilometre-long structure below the main Midwest conductor. At least four drill holes will also be used to evaluate the potential along this structure.


Ongoing exploration continues to define favourable targets on the 4,230-hectare, 22.5% owned McClean property, where the JEB mill is currently being expanded to 12.0 million pounds per year capacity to handle ore from Cigar Lake. Exploration activities in 2006, principally drilling, will be concentrated in three areas.

At the Bena Lake area, located west of the Sue E deposit where stripping is currently underway in preparation for ore mining in 2007, 10 to 12 drill holes will test a major 23-metre unconformity offset with associated chemical alteration discovered during last winter's program.

Drilling in 2006 should also test the basement potential of the McClean South podiform mineralization. No exploration has been carried out in this area since the early 1980s when exploration was only directed towards unconformity targets.

The third area, defined by previous geophysical surveys, will test the easterly strike extension of the JEB deposit. Two or three diamond drill holes are planned.


The Wolly property is extremely large and well located and surrounds the McClean property on three sides. Denison is earning up to a 22.5% interest in this 23,700 hectare property by spending up to $5 million over a six-year period.

Virtually all of the past exploration work at Wolly was oriented toward unconformity, sandstone hosted targets with little attention paid to existing basement alteration which may be indicative of basement hosted mineralization. Exploration during 2005 included an airborne gravity gradiometer survey to aid in identifying hitherto unknown differences in relative unconformity elevations which may be indicative of faulting. In addition, core relogging and the compilation of all drill hole and geophysical data was carried out. This compilation work, which is ongoing, has begun to define new drill targets.

The initial focus is on the Snake Lake area, which is interpreted to represent the geological extension of the JEB trend. Very shallow depths to the unconformity coupled with high geological potential means that even low tonnage discoveries can quickly become open pittable for the nearby McClean mill. Three high priority targets have been identified and are planned to be tested in 2006 by a 5,000 metre, two-stage drilling program. The target area exhibits:

- Anomalous uranium, up to 0.13% U3O8 over 1.0 metre in hole CO-27

- Correlation with structural trends and evidence of unconformity offsets

- Area wide illiltic clay with local kaolinite, hydrothermal hematite and other alteration

The Wolly property will be a major thrust of Denison's on-going exploration efforts, because of its size, its proximity to the McClean mill and the shallow sandstone cover which averages 100 metres. There are 15 conductive trends which by themselves are important targets and on which exploration will focus in the months and years ahead. Several of the more significant trends identified to date follow. The grades and widths are all drill intersections.

- Top Creek area, conductor strongly anomalous in Cu, Ni, As and V, with significant unconformity offsets, and only drilled at 200 to 400 metre intervals

- Moonlight area, with basement mineralization of 1.18% U3O8 over 0.5 metre at a 45-metre depth, and sandstone mineralization of 1.78% U3O8 over 4.75 metres at a 40-metre depth

- Mallen Lake area, with 5.95% U3O8 over 0.3 metres and 2.49% U3O8 over 0.3 metres with significant unconformity elevation differences

- Burnt Island with 1.8% U3O8 over 0.5 metres in the basement with intense hydrothermal alteration and graphite destruction

- Emperor trend which represents the strike extension of the high-grade Dawn Lake trend

Compilation is at the very earliest stages on all these zones where fieldwork is currently scheduled for the fall of 2006.


Denison holds a 14.76% interest in the Waterfound uranium exploration project, which is located west of the Dawn Lake property. In 1991, a drill intersection of 4.48% U3O8 over 10.53 metres was encountered in the northern portion of the property. On the same conductor, but east on the adjoining La Rocque property, a second uraniferous drill intersection was made, thus enhancing the exploration potential of this conductor.

Depths to the unconformity of 550 metres have hampered exploration to date where follow-up drilling to the 1991 discovery has only been on 100-metre spacing. This drill spacing will need to be decreased to at least 50 metres or possibly 25 metres.

The 2006 exploration program for Waterfound will consist of a property-wide airborne gravity survey, linecutting and ground geophysical surveys.

Wheeler River

The Wheeler River property is a 12,225 hectare, well-located uranium exploration project adjoining and along strike west from the McArthur River mine. The fundamental feature that controls the basement hosted uraniferous mineralization at McArthur is a quartzite ridge. This ridge represents the paleotopography prior to deposition of the sandstone and is thought to have acted as an impenetrable dam focusing uraniferous fluids. The strike extension of the McArthur quartzite ridge extends onto the Wheeler property.

Denison is the operator for Wheeler and is currently earning an additional 20% interest, to increase its interest to 60%, by funding $7 million in exploration expenditures over a seven-year period.

The 2005 exploration program included both ground and airborne geophysics and diamond drilling. The focus of the work to date has been the unconformity on the west boundary of the quartzite ridge. Eight drill holes have been completed to date, totalling 3,271 metres, and drilling is continuing. Several holes were strongly anomalous in boron, clay mineral alteration and contained elevated radioactivity from downhole probing. Also in this immediate area, a major sandstone disruption zone, anomalously radioactive and with documented McArthur style chromium-dravite chemical alteration patterns, is being re-evaluated. Drilling ceased in that area 20 years ago when sandstone and unconformity hosted mineralization were the targets and we are now investigating the zone as a reflection of basement mineralization.

The exploration program will continue through the remainder of 2005 and throughout 2006. A total of 13,500 metres of drilling is planned for 2006 which will include a number of uraniferous zones in wet areas that are only winter accessible. Some additional geophysics is also planned for the coming year.

The technical information contained in this Press Release is reported by William C. Kerr, Denison's Director, Resource Evaluations, who is a "qualified person" as defined in NI 43-101.

Additional Information

Additional information on Denison is available on SEDAR at and on the Company's website at

About Denison

Denison Mines Inc. is a uranium exploration, development and production company whose principal assets are a 22.5% interest in one of the world's largest uranium facilities at McClean Lake in Northern Saskatchewan and its 25.17% interest in the Midwest Uranium Project. It is also engaged in mine decommissioning and environmental services through its Denison Environmental Services division and provides management services to Uranium Participation Corporation. Additional information on Denison is available on SEDAR at and on Denison's website at

Some disclosures included in this release respecting production, capital spending, development schedules, expenses, markets, and milling arrangements represent forward-looking statements. Forward-looking statements generally can be identified by the use of forward-looking terminology such as "may", "will", "expect", "intent", "estimate", "anticipate", "believe" or "continue" or the negative thereof or variations thereon or similar terminology. Such statements are based on assumptions and estimates related to future market conditions. These statements involve risks and uncertainties relating to, among other things, changes in commodity prices, unanticipated reserve and resource grades, results of exploration activities, timeliness of government approvals, economic risk, actual performance of plant, equipment and processes relative to specifications and expectations and unanticipated environmental impacts on operations. While management reviews the reasonableness of its assumptions and estimates, unusual and unanticipated events may occur which render them inaccurate. Under such circumstances, future performance may differ materially from those expressed or implied by the forward-looking statements.

Contact Information

  • Denison Mines Inc.
    E. Peter Farmer
    President and Chief Executive Officer
    (416) 979-1991 Extension 231
    Denison Mines Inc.
    James R. Anderson
    Executive Vice President and Chief Financial Officer
    (416) 979-1991 Extension 372