Denison Reports 9.1% U3O8 over 3.7 Metres from the High-Grade Huskie Zone at Waterbury Lake with Receipt of Assays
Denison Mines Corp.
1100 – 40 University Ave
Toronto, ON M5J 1T1
www.denisonmines.com
@DenisonMinesCo
PRESS RELEASE
DENISON REPORTS 9.1% U3O8 OVER 3.7 METRES FROM
THE HIGH-GRADE HUSKIE ZONE AT WATERBURY LAKE
WITH RECEIPT OF ASSAYS
Toronto, ON – October 11, 2017 Denison Mines Corp. (“Denison” or the “Company”) (DML: TSX, DNN:
NYSE MKT) is pleased to report a significant increa se in uranium grades for the Huskie zone following
receipt of assay results from the Company’s summer 2017 drilling program on the Waterbury Lake project.
On average, assay grades (“U 3O8”) were 26% higher than the previously reported preliminary radiometric
probe grades (“eU 3O8”) and grade x thickness (GT) values were 12% highe r. Of particular note are the
assay results from drill hole WAT17-446A, which ret urned 9.1% U 3O8 over 3.7 metres, including 16.8%
U3O8 over 2.0 metres.
The assay results confirm high-grades of the basement-hosted Huskie zone which measures approximately
100 metres in strike length and remains open in all directions. The Huskie zone is located approximate ly
1.5 kilometres to the northeast of the property’s J Zone uranium deposit.
Highlight assay results include:
• 9.1% U 3O8 over 3.7 meters; including 16.8% U 3O8 over 2.0 meters in drill hole WAT17-446A
• 1.7% U 3O8 over 7.5 meters; including 8.2% U 3O8 over 1.5 meters in drill hole WAT17-449
• 1.5% U 3O8 over 4.5 meters; including 3.9% U 3O8 over 1.0 meter in drill hole WAT17-450A
Dale Verran, Denison’s Vice President of Exploration, commented, “We are not only impressed by the
high-grades confirmed by the assay results, but also the substantial thicknesses of the mineralized
lenses. This, together with the strong alteration h alo surrounding mineralization and the favorable
geological setting, suggests significant exploratio n potential. The east-west corridor which hosts
Huskie is wide-open to the west and land-based for over one kilometre. We are excited to get the
drills turning again in 2018, in what is expected to be an aggressive follow-up drilling campaign.”
The Huskie Zone
Following the high-grade uranium intersection in th e first drill hole of the summer 2017 drilling prog ram, a
further eight holes were completed on an approximate 50 x 50 metre spacing. This initial drilling campaign
on the east-west geological trend at Waterbury Lake has allowed for the wide-spaced definition of a zo ne
of entirely basement-hosted mineralization with geo logical features consistent with basement-hosted
deposits in the Athabasca Basin.
The mineralized zone, which covers the extent of th e current drilling, occurs between 50 and 175 metre s
vertically below the sub-Athabasca unconformity (26 5 and 390 metres vertically below surface) and
measures approximately 100 metres along strike (cur rent extent of drilling), up to 120 metres along di p,
with individual lenses varying in interpreted true thickness between approximately 2 and 7 metres. The
zone is wide-open in all directions in terms of the mineralization and associated alteration intersected.
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Assay Results
Assay results for the summer 2017 drill program are provided in Table 1 as composites using a minimum
length of 1 metre. Sampling and assay procedures ar e described in detail below. A location map of the
Huskie zone is provided in Figure 1. Highlight assa y result drill intersections are shown on the simpl ified
basement geology map and inclined longitudinal section in Figures 2 and 3 respectively.
Table 1. Assay results for the Waterbury Lake summer 2017 drill program.
Drill Hole From (m) To (m) Length (m) 6 U 3O8 (%) 1,3,5 Corresponding
eU 3O82 result
WAT17-443 284.1 288.6 4.5 0.17 0.13% / 12.6 m
and 290.2 291.2 1.0 0.09 Merged with interval above
and 298.0 299.0 1.0 1.2 0.77% / 1.2 m
WAT17-444 341.3 342.3 1.0 0.07 0.08% / 1.0 m
and 347.4 348.4 1.0 0.59 0.44% / 1.0 m
and 362.0 363.0 1.0 0.17 0.14% / 1.0 m
WAT17-445 271.5 272.5 1.0 0.06 Below cut-off
and 278.0 279.0 1.0 0.17 0.13% / 1.0 m
WAT17-446A 306.5 310.2 3.7 9.1 3.7% / 3.9 m
including 4 307.7 309.7 2.0 16.8 7.8% / 1.8 m
and 336.1 337.1 1.0 0.23 0.24% / 1.0 m
and 342.3 343.8 1.5 0.08 0.07% / 1.6 m
WAT17-449 321.5 322.5 1.0 0.11 0.1% / 1.3 m
and 345.1 346.1 1.0 0.07 0.25% / 1.0 m
and 349.4 350.4 1.0 0.05 0.06% / 1.0 m
and 369.0 376.5 7.5 1.7 1% / 7.6 m
including 4 375.0 376.5 1.5 8.2 4.6% / 1.4 m
and 379.3 384.3 5.0 0.29 0.21% / 5.1 m
including 4 380.8 381.8 1.0 1.0 Merged with interval above
WAT17-450A 279.0 280.0 1.0 0.18 0.08% / 2.9 m
and 314.5 315.5 1.0 0.41 0.77% / 7.9 m
and 318.5 323.0 4.5 1.5 Merged with interval above
including 4 319.0 320.0 1.0 3.9 3.3% / 1.0 m
including 4 321.5 322.5 1.0 2.0 1.3% / 1.0 m
and 335.0 336.0 1.0 0.10 0.11% / 1.2 m
WAT17-451 402.0 405.5 3.5 0.28 0.27% / 3.7 m
and 420.5 421.5 1.0 0.18 0.07% / 1.0 m
Notes:
1. U 3O8 is the chemical assay of mineralized split core samples.
2. eU 3O8 is radiometric equivalent U 3O8 derived from a calibrated total gamma downhole probe. eU 3O8 results are preliminary
in nature and all mineralized intervals are subject to definitive chemical U 3O8 assay where core recovery permits.
3. Intersection interval is composited above a cut- off grade of 0.05% U 3O8 unless otherwise indicated.
4. Intersection interval is composited above a cut- off grade of 1.0% U 3O8.
5. Composites are compiled using 1.0 metre minimum ore thickness and 2.0 metres maximum waste.
6. As the drill holes are oriented steeply toward t he south-southeast and the mineralized lenses are i nterpreted to dip
moderately to the north, the true thickness of mineralization is expected to be approximately 75% of the intersection lengths.
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Geology of the Huskie Zone
The mineralized zone is hosted primarily within a faulted, graphite-bearing pelitic gneiss (“graphitic gneiss”)
which forms part of an east-west striking, northerl y dipping package of metasedimentary rocks flanked to
the north and south by granitic gneisses. The Athabasca Group sandstones that unconformably overly the
basement rocks are approximately 210 metres thick. A major reverse fault, occurring along the upper
contact of the graphitic gneiss, has resulted in ap proximately 15 metres of offset of the sub-Athabasc a
unconformity. Preliminary interpretation indicates the mineralization occurs as parallel, stacked lens es
which are conformable to the foliation and fault pl anes within the graphitic gneiss. The high-grade
mineralization is comprised of massive to semi-mass ive uraninite (pitchblende) and subordinate bright
yellow secondary uranium minerals occurring along f ault or fracture planes, or as replacement along
foliation planes. Disseminations of lower grade min eralization occur within highly altered rocks proxi mal to
fault planes. The mineralization is intimately asso ciated with hematite, which both occur central to a broad
and pervasive alteration envelope of white clays, chlorite and silicification.
Waterbury Lake Property
The Waterbury Lake property consists of multiple cl aims covering 40,256 hectares, and is located in th e
infrastructure rich eastern portion of the Athabasc a Basin region in northern Saskatchewan. The prope rty
is jointly owned by Denison (64.22%) and Korea Wate rbury Uranium Limited Partnership (“KWULP”)
(35.78%) through the Waterbury Lake Uranium Limited Partnership (“WLULP”). KWULP consists of a
consortium of investors in which Korea Hydro & Nuclear Power (“KHNP”) holds a majority position. KHNP
is also a significant shareholder in Denison, holdi ng 58,284,000 common shares of Denison, which
represents approximately 10.42% of the Company’s issued and outstanding common shares.
The J Zone deposit, located on the Waterbury Lake p roperty, occurs at the sub-Athabasca unconformity
and is estimated to contain indicated resources of 12.8 million pounds U 3O8 based on 291,000 tonnes of
mineralization an average grade of 2.0% U 3O8. The Roughrider deposit, on Rio Tinto’s Roughrider property,
is located immediately along strike to the east of J Zone deposit and occurs at the sub-Athabasca
unconformity and below within the basement rocks. Prior to acquisition by Rio Tinto in 2012, the Roughrider
deposit was estimated to contain indicated resources of 17.2 million pounds U 3O8 based on 394,200 tonnes
of mineralization at an average grade of 1.98% U 3O8 and inferred resources of 40.7 million pounds U 3O8
based on 161,600 tonnes of mineralization at an average grade of 11.43% U 3O8.
For more information on the J Zone deposit, please refer to the Technical Report on the Mineral Resource
Estimate on the J Zone Uranium Deposit, Waterbury L ake Property dated September 6, 2013 by Allan
Armitage, Ph. D., P. Geo, and Alan Sexton, M.Sc., P .Geo, of GeoVector Management Inc. available on
Denison’s website and under the Company’s profile on SEDAR (www.sedar.com). For further details on
the Roughrider deposit, prior to acquisition by Rio Tinto in 2012, please refer to the Preliminary Eco nomic
Assessment Technical Report for the East and West Z ones Roughrider Uranium Project, Saskatchewan
dated September 13, 2011 by SRK Consulting (Canada) Inc. available under Hathor Exploration Limited’s
profile on SEDAR.
Sampling and Assay Procedures
During exploration programs the Company reports gra de results as preliminary radiometric equivalent
grades ("eU 3O8") derived from a downhole total gamma probe. The C ompany subsequently reports
definitive assay grades following sampling and chemical analysis of the mineralized drill core.
The Company’s reported radiometric equivalent grades provide best estimates of initial grades, however
these can vary according to the chemical assay resu lts, particularly for basement-hosted deposits due to
their vein-like nature, and on average tend to be conservative. The use of radiometric equivalent grades is
common practice in the uranium exploration and mini ng industry and is particularly useful where core l oss
occurs, or no drilling material is available for chemical analysis.
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The sampling of drill core is undertaken on site by splitting the core in half, with one half submitte d for
analysis and the other half retained in the core bo x for future reference. Drill core with anomalous t otal
gamma radioactivity (>500 counts per second) is typ ically sampled over 0.5 metre intervals. Uranium
assays are performed by the Saskatchewan Research C ouncil (“SRC”) Geoanalytical Laboratories using
an ISO/IEC 17025:2005 accredited method for the det ermination of U 3O8 weight %. Sample preparation
involves crushing and pulverizing core samples to 90% passing -106 microns. The resultant pulp is digested
using aqua-regia and the solution analyzed for U 3O8 weight % using ICP-OES. Core recovery at Huskie is
typically 100% and therefore radiometric equivalent U 3O8 grades ("eU 3O8") are not required as a substitute
for chemical U 3O8 assays. In addition to internal checks by SRC Geoanalytical Laboratories, the Company
has rigorous quality assurance and quality control ("QAQC") procedures including the insertion of standard
reference materials, blanks and field duplicates. T he assay data is subject to verification procedures by
qualified persons employed by Denison prior to disclosure. For further details on the downhole total gamma
probe procedures and the assay, QAQC and data verif ication procedures please see Denison's Annual
Information Form dated March 23, 2017 filed under the Company's profile on SEDAR (www.sedar.com).
Qualified Persons
Dale Verran, MSc, P.Geo, Pr.Sci.Nat., Denison's Vice President, Exploration, who is a Qualified Person in
accordance with the requirements of NI 43-101 has r eviewed and approved the technical information
contained in this release.
About Denison
Denison is a uranium exploration and development company with interests focused in the Athabasca Basin
region of northern Saskatchewan, Canada. In addition to its 60% owned Wheeler River project, which hosts
the high-grade Phoenix and Gryphon uranium deposits , Denison's exploration portfolio consists of
numerous projects covering approximately 359,000 he ctares in the Athabasca Basin region, including
340,000 hectares in the infrastructure rich eastern portion of the Athabasca Basin. Denison's interest s in
Saskatchewan also include a 22.5% ownership interest in the McClean Lake joint venture (“MLJV”), which
includes several uranium deposits and the McClean L ake uranium mill, which is currently processing ore
from the Cigar Lake mine under a toll milling agreement, plus a 25.17% interest in the Midwest deposit and
a 64.22% interest in the J Zone deposit on the Wate rbury Lake property. Both the Midwest and J Zone
deposits are located within 20 kilometres of the McClean Lake mill.
Denison is also engaged in mine decommissioning and environmental services through its Denison
Environmental Services division and is the manager of Uranium Participation Corp., a publicly traded
company which invests in uranium oxide and uranium hexafluoride.
For more information, please contact
David Cates (416) 979-1991 ext. 362
President and Chief Executive Officer
Sophia Shane (604) 689-7842
Investor Relations
Follow Denison on Twitter @DenisonMinesCo
Cautionary Statement Regarding Forward-Looking Statements
Certain information contained in this press release constitutes "forward-looking information", within the meaning of the United States
Private Securities Litigation Reform Act of 1995 an d similar Canadian legislation concerning the busin ess, operations and financial
performance and condition of Denison.
Generally, these forward-looking statements can be identified by the use of forward-looking terminolog y such as "plans", "expects",
"budget", "scheduled", "estimates", "forecasts", "intends", "anticipates", or "believes", or the negatives and/or variations of such words and
phrases, or state that certain actions, events or results "may", "could", "would", "might" or "will be taken", "occur", "be achieved" or "has
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the potential to". In particular, this press release contains forward-looking information pertaining to the following: exploration (including
drilling) and evaluation activities, plans and objectives, and Denison’s percentage in its properties and its plans and agreements with its
joint venture partners, as applicable. Statements relating to "mineral reserves" or "mineral resources" are deemed to be forward-looking
information, as they involve the implied assessment, based on certain estimates and assumptions that the mineral reserves and mineral
resources described can be profitably produced in the future.
Forward looking statements are based on the opinions and estimates of management as of the date such statements are made, and they
are subject to known and unknown risks, uncertainties and other factors that may cause the actual results, level of activity, performance
or achievements of Denison to be materially different from those expressed or implied by forward-looking statements. Denison believes
that the expectations reflected in this forward-looking information are reasonable but no assurance can be given that these expectations
will prove to be accurate and may differ materially from those anticipated in this forward looking information. For a discussion in respect
of risks and other factors that could influence forward-looking events, please refer to the factors discussed in Denison's Annual Information
Form dated March 23, 2017 under the heading "Risk Factors". These factors are not, and should not be construed as being exhaustive.
Accordingly, readers should not place undue reliance on forward-looking statements.
The forward-looking information contained in this press release is expressly qualified by this cautionary statement. Any forward-looking
information and the assumptions made with respect thereto speaks only as of the date of this press release. Denison does not undertake
any obligation to publicly update or revise any forward-looking information after the date of this press release to conform such information
to actual results or to changes in Denison's expectations except as otherwise required by applicable legislation .
This document contains certain information derived from third-party publications and reports, includin g estimates of resources and
mineralization of the Roughrider deposit, which Denison believes are reliable but have not been independently verified by Denison.
Cautionary Note to United States Investors Concerning Estimates of Measured, Indicated and Inferred Mineral Resources: This
press release may use the terms “measured”, “indicated” and “inferred” mineral resources. United States investors are advised that while
such terms are recognized and required by Canadian regulations, the United States Securities and Exchange Commission does not
recognize them. “Inferred mineral resources” have a great amount of uncertainty as to their existence, and as to their economic and legal
feasibility. It cannot be assumed that all or any part of an inferred mineral resource will ever be upgraded to a higher category. Under
Canadian rules, estimates of inferred mineral resources may not form the basis of feasibility or other economic studies. United States
investors are cautioned not to assume that all or any part of measured or indicated mineral resources will ever be converted into mineral
reserves. United States investors are also cautioned not to assume that all or any part of an inferred mineral resource exists, or is
economically or legally mineable.
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Figure 1: Location of summer 2017 drill collars on Denison’s Waterbury Lake project.
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Figure 2: Simplified basement geology map of the Huskie zone at the sub-Athabasca unconformity.
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Figure 3: Inclined longitudinal section of the Huskie zone (looking south).