VANCOUVER (miningweekly.com) – Uranium explorer and development company Denison Mines has discovered more high-grade uranium ore 600 m and 1 km to the northeast of the Gryphon uranium deposit, on the company’s 63.3%-owned Wheeler River project, in northern Saskatchewan, the company reported on Wednesday.
With the 21 153 m winter drilling programme in hand, comprising 29 diamond drill holes, the exploration campaign was focused on step-out drilling along strike of the Gryphon deposit and to conduct reconnaissance-level regional exploration along the K-North and K-West trends.
Denison advised that the results were still preliminary in nature, and it is awaiting assay results to confirm the data.
The company reported that high-grade intercepts were obtained at the sub-Athabasca unconformity along the K-North trend, to the northeast of Gryphon, from reconnaissance drill fences spaced 200 m apart, including 0.55% uranium oxide equivalent (eU3O8) over 5.6 m, located 600 m northeast of Gryphon, including 2.3% eU3O8 over 1 m in drill hole WR-704; and 0.94% eU3O8 over 3.5 m, located 1 km northeast of Gryphon, including 2.7% eU3O8 over 1 m in drill hole WR-710D1.
Denison advised that the results indicate a continuation of the Gryphon mineralising system to the northeast, and highlight the potential for the discovery of an additional high-grade uranium deposit within the basement or at the unconformity along strike of Gryphon.
Further, wide-spaced reconnaissance drilling along the K-West trend, about 500 m west and northwest of the Gryphon deposit, has identified the hallmarks of a significant fertile trend with the potential to host high-grade uranium – including a large reactivated graphite-bearing fault zone, hydrothermal alteration and elevated radioactivity.
“The last time Denison undertook any significant regional exploration on Wheeler was in 2014, which resulted in the discovery of Gryphon. The initiation of regional exploration once again in 2018 has been met with positive results delivering high-grade intercepts along the K-North trend and identifying K-West as a significant fertile trend.
“Furthermore, the initial step-outs from Gryphon confirm potential to continue to expand the mineral resource. We look forward to the summer drilling programme to continue to test regional targets across the Wheeler River property and commence follow-up activities where warranted,” VP for exploration Dale Verran said in a statement.
A recent resource update calculated the Gryphon deposit to contain 61.9-million pounds of U3O8, held in 1.6-million tonnes grading 1.71% U3O8, in the indicated resource category, as well as 1.9-million pounds, held in 73 000 t at an average grading of 1.18% U3O8, in the inferred resource classification.
Wheeler River is also host to the Phoenix deposit, which Denison estimates to contain 70.2-million pounds of U3O8, held in 166 000 t grading 19.1% U3O8, in the indicated category, with 1.1-million pounds of U3O8, held in 9 000 t grading 1.7% U3O8, in the inferred category.
Denison last year sanctioned moving the Wheeler River project to the prefeasibility study stage. An April 2016 preliminary economic assessment that used a uranium price of $44/lb, calculated a pre-tax net present value of C$513-million for Wheeler River, and an internal rate of return of 20.4%. Cash operating costs for ore mined from the Gryphon deposit are pegged at C$14.28/lb and from Phoenix at $22.15/lb.
Denison owns a 66.3% stake and is the operator of Wheeler River. Cameco and private investment vehicle JCU Exploration hold the balance of the project.