A new look at basement-hosted mineralization in the Horseshoe and Raven deposits, eastern Athabasca Basin

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A new look at basement-hosted mineralization in the Horseshoe and Raven deposits, eastern Athabasca Basin

  1. 1. Horseshoe and Raven deposits A new look at basement-hosted basement hosted mineralization in the Horseshoe andRaven deposits, eastern Athabasca Basin David Rhys, Sierd Eriks and Leo Horn UEX C Corporation ti Saskatchewan Geological Survey Open House, Nov. 29, 2010
  2. 2. Horseshoe and Raven deposits Forward-Looking StatementsThis presentation contains “forward-looking statements” that are based on UEX’s currentexpectations, estimates, forecasts and projections. These forward-looking statementsinclude statements regarding UEX’s resource estimates, outlook for our future operations,plans and timing for the commencement or advancement of exploration activities on ourproperties, and other expectations, intention and plans that are not historical fact. Thewords “estimates”, “projects”, “expects”, “intends”, “believes”, “plans”, or their negatives orother comparable words and phrases are intended to identify forward-looking statements. forward lookingSuch forward-looking statements are based on certain factors and assumptions and aresubject to risks, uncertainties and other factors that could cause actual results to differmaterially from future results expressed or implied by such forward-looking statements.Important factors that could cause actual results to differ materially from UEX’s expectationsincludei l d uncertainties relating t i t t i ti l ti to interpretation of d ill results and geology, additional d illi t ti f drill lt d l dditi l drillingresults, continuity and grade of deposits, public acceptance of uranium as an energy source,fluctuations in uranium prices and currency exchange rates, changes in environmental andother laws affecting uranium exploration and mining, and other risks and uncertaintiesdisclosed in UEX’s Annual Information Form and other filings with the securities commission gon SEDAR. Many of these factors are beyond the control of UEX. Consequently, all forward-looking statements made in this presentation are qualified by this cautionary statement andthere can be no assurance that actual results or developments anticipated by UEX will berealized. For the reasons set forth above, investors should not place undue reliance on suchforward-looking statements.forward looking statements Except as required by applicable law UEX disclaims any law,intention or obligation to update or revise forward-looking information, whether as a resultof new information, future events or otherwise.
  3. 3. Hidden Bay setting Horseshoe and Raven deposits Horseshoe and Raven are located on UEX’s 100% owned Hidden Bay project on the eastern margin of the Athabasca Basin
  4. 4. Horseshoe and Raven deposits Hidden Bay p j y project  57,000 hectare Tent-Seal property in eastern Athabasca uranium district (area has >360 Telephone million lb production + illi lbs d ti Shamus Vixen resources, excludes Cigar Lake) Rabbit Lake fault Horseshoe  Contains Horseshoe, Raven and West Bear and Raven deposits Wolf  Deposits located only Rhino 4 km south of Cameco’s Rabbit Lake mill facility Dwyer in an area of excellentWest Bear infrastructure
  5. 5. Horseshoe and Raven deposits Horseshoe-Raven history Two deposits approx. 1 km apart discovered through follow-up of a radioactive boulder train in the early 1970’s by Gulf Minerals Gulf drilled 202 widely spaced (50 to 100 m apart) drill holes between 1972 and 1978 to define historical, non-compliant resources of 23 million lbs U3O8 grading at 0 16% in both 0.16% deposits -9 R NC R -1 HS -13 S A A HS Y V LIN -4 3 -4 HS E -45 HS N E HS Cross section through Horseshoe HS deposit prior to drilling by UEX: 1.5m @ 0.25% U3O8 4.11m @ grade continuity perceived to be 0.88% 0 88% U3O8 discontinuous, but drill holes very 0 100 widely spaced 1.2m @ 0.22% U3O8 meters 16.0m 16 0 @ 0.8% U3O8 Horseshoe zone Section 148+00S View Northeast
  6. 6. Horseshoe and Raven deposits UEX drilling, 2005-2009 Potential to upgrade and further explore the deposits beyond the Gulf resources was recognized. Between 2005 and 2009 UEX completed 663 drill holes (198 000 m of 2009, (198,000 drilling) at Horseshoe and Raven to establish resources at 15 to 30 m hole spacing. Historical drill holes could not be used due to QA/QC concerns. Drilling established continuity of mineralization expanded the deposit mineralization, footprints into areas not historically drilled, and identified areas of higher grade mineralization within the deposits.
  7. 7. Horseshoe and Raven deposits Resources based on drilling to July 23, 2009 July 2009 43-101 complaint resources for the Horseshoe and Raven deposits estimated by K. Palmer, P. Geo. of Golder Associates, at a cutoff grade of 0.05% U3O8 : 0 05% Deposit Tonnes U3O8 % U3O8 (pounds) Indicated Horseshoe 5,119,700 0.203 22,895,000 Resources Raven 5,173,900 0.107 12,149,000 Totals 10,293,600 0.170 35,044,000 Deposit Tonnes U3O8 % U3O8 (pounds) Inferred Horseshoe 287,000 0.166 1,049,000 Resources R Raven 822,200 822 200 0.092 0 092 1,666,000 1 666 000 Totals 1,109,200 0.111 2,715,000 In addition to these deposits, Hidden Bay also contains the West Bear deposit. At a p y pcutoff grade of 0.05% U3O8, West Bear is host to 79,914 tonnes grading 0.908 % U3O8 (1.57 million pounds U3O8) in near surface (<30m) resources (2009 N.I. 43-101 complaint resources)
  8. 8. - property straddles the gradational contact betweenthe Paleoproterozoic Mudjatik Domain to the NW Geological setting Horseshoe and Raven deposits(granitic gneiss domes + psammitic to peliticg Central Hidden Bay property – Geological settinggneiss), and the Wollaston Domain to the southeast ), Horseshoe Raven
  9. 9. - Deposits lie outside of Horseshoe and Raven depositsAthabasca Basin: sandstoneeroded here Geological setting- Competent metamorphic hostrocks Local geological setting of the Horseshoe and Raven deposits
  10. 10. Host lithologies Horseshoe and Raven deposits Ca c a os c o calc-silicate gneiss: Calc-arkosic to ca c s ca e g e ss Qua Quartzite: >85% quartz, with K- e 85% qua , plagioclase-K-feldspar-pyroxene-biotite- feldspar, biotite, 20-70 m thick – amphibole – above mineralization hosts upper parts of mineralization Arkosic quartzite: 40-65% quartz, 20-55% 40 65% 20 55% Lower biotite-quartz-feldspar, p q p pelitic andfeldspars; massive to banded (relict beds), calc-silicate gneiss: mixed assemblage 20 to 150 m thick – main host to of biotite and calc-silicate bearing ortho- mineralization and paragneiss – below mineralization
  11. 11. Structural setting Horseshoe and Raven deposits Folded lower biotite-quartz- feldspar gneiss beside Raven camp, view down, top to NE. Shows style of open D2 (F2) folding g Two phases of syn metamorphic Hudsonian deformation at amphibolite syn-metamorphic grade. Two metamorphic pulses between 1830 - 1795 Ma (Annesley et al.) D1 = Early penetrative S1 foliation/gneissosity is dominant foliation. Regionally associated with tight to isoclinal folds folds. D2 = Open F2 folds with second, steeply dipping spaced to penetrative NE trending foliation. Form dominant NE trending folds and principal geometry of lithologies in local area (e g Raven Syncline) with horizontal to northeast (e.g. plunging fold axes. Non-cylindrical fold axes regionally. Later crenulations and minor folds in later, retrograde lower strain events
  12. 12. Horseshoe and Raven deposits Geological settingHematite breccias and intense clay alteration + silicificationalong Dragon Lake fault: fluid Local geological setting of the conduit for mineralization? Horseshoe and Raven deposits Post-metamorphic and in part post-Athabasca brittle faulting regionally in NE trending reverse faults (e g Rabbit Lake, Collins Bay faults) and in (e.g. Lake faults), north-trending Tabbernor sinistral faults such as the Dragon Lake fault Dragon Lake fault lies on east side of deposit – surrounded by intense alteration which joins the eastern parts of the Horseshoe alteration zone: may have been an important fluid conduit for mineralization ?Pre-mineral NE trending, SE dipping fault zone along mineralized zones
  13. 13. Horseshoe and Raven deposits Uranium mineralization Deposits are entirely basement hosted and developed t d th of d l d to depths f 450 m below the current surface. L Locally preserved ll d paleoweathering suggests current surface was close to the now Local geological setting of the eroded unconformity. Horseshoe and Raven deposits Deposits are developed over a 2.3 km strike length along and southeast of the Raven syncline Mineralization occurs over a strike of 800 m at syncline. Horseshoe and 900 m at Raven, with a 600 m poorly mineralized gap between the deposits Mineralization occurs in areas of hematite alteration within and within, surrounding southeast dipping clay-chlorite alteration zones that may be localized along pre-mineral faults
  14. 14. Horseshoe and Raven deposits Exploration techniques Horseshoe Horseshoe H h Raven Raven DC resistivity, 175 m modeled depth, Horseshoe-Raven Horseshoe Raven area Gravity data Warm colours = resistivity highsGeophysical exploration: Gravity and Resistivity Deposits initially discovered partially as a result of a gravity survey by f Gulf Minerals, on basis of gravity low over Rabbit Lake deposit, in follow up of radioactive boulder train G i and DC R i i i l Gravity d Resistivity lows id if areas of clay alteration identify f l l i associated with uranium mineralization. Mineralization is often on the margins of the most intense lows, beside areas of most intense alteration
  15. 15. Horseshoe and Raven deposits Exploration techniques Resistivity section, 4700N H -02 9 H S-047 U 0 18 H 022 H 054 U 4 U 0 U 1 U 2 U 3 H 9 H 58 H -04 24 H -04 H 2 H -04 1 H -0 -0 U 27 -0 -0 62 -0 65 -0 - - 69 64 U U U S H -0 U U -0 H -0 -0 H -0 Lithologies S U U U H H H H Pelitic gneiss CARK 400 RL 50 50 m Metaquartzite m 50 m 50 m 50 50 m 50 50 50 m m 50 m 50 m m m 50 m 50 m 50 m 50 m 50 m Arkosic quartzite 10 0 10 0 10 QZIT Calc-arkose 0 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 Alteration 15 0 15 0 15 0 Hematite 300 RL 150 150 150 150 150 150 150 150 150 150 150 Moderate clay 20 150 150 150 20 0 150 0 Mineralization 200 200 200 200 20 0 200 200 200 200 200 200 Hematite-pitchblende- 0.21 % 200 200 200 200 uranophane-clay 28.95m A zone 0.30 % 200 RL 5.65m 0.395 % Grade U3O8 11.56m 250 250 Core length (m) 250 250 250 0.09 % 250 250 250 250 250 Bz 15.2m A2 zo A3 250 250 250 250 on ne zo e 0.14 % Drill holes 13 we 0.15 % 0.17 % ne 14.9m ARKQ 35 -0 0 st m HS 300 10.4m 300 13.7m 30 0 300 300 300 300 300 0.18 % UEX drill holes 300 8.5m 300 Bz 300 300 300 Historic Gulf drill holes 0.20 % 300 on 5 0.12 0 12 % 0.23 % 04 e S- ea 11.0m H 100 RL 13.9m 15.0m 35 0 0.10 % st 350 15.4m 350 350 350 350 350 350 350 350 400 0 50 100 C zo 400 400 400 ne Meters 0 RL Horseshoe Deposit 0.61% 17.65m Section 4700N 4700 E 4800 E 4900 E 5000 E 5100 E 450 Looking Northeast 450 Resistivity inversion successfully modeled alteration, and patterns arelocally independent of lithology Resistivity also showed significant down dip potential of mineralizationbeyond the limits of Gulf drilling
  16. 16. Uranium mineralization Horseshoe and Raven deposits Mineralizationand alteration cutobliquely across the folded metamorphic sequence and preferentially occur in arkosic quartzite
  17. 17. Horseshoe and Raven deposits Horseshoe mineralization stylePitchblende main U mineral, occurring in common mineralization styles: “Nodular” and veinlet, blebby pitchblende in red-brown hematite-clay alteration. M b b d d and may cut across f li ti with shallow di lt ti May be banded, d t foliation ith h ll dips Disseminated pitchblende in competent arkosic quartzite with hematite- illite and/or green chlorite alteration (most of eastern Horseshoe deposit)Paragenetically late U-silicates (boltwoodite, uranophane, and locally coffinite) overprint pitchblende, overgrowing or crosscutting as veinlets “Nodular” style Disseminated style
  18. 18. Horseshoe and Raven deposits Horseshoe mineralogy Dominant pitchblende texture is “woven intergrowth” – intergrown with hematite, chlorite and clays (i.e. synchronous) Massive clots and fractures in quartz also common in both nodular and disseminated styles Mineralization has low As (<100 ppm), Mo (<20 ppm), Se (<2 ppm), Co (<100 ppm), Ni (<100 ppm), V (<150 ppm) in >0.2% U3O8 samples = “clean” mineralization no deleterious elements typical of basement clean mineralization, elements, unconformity-type uranium signature such as Eagle Point Metallurgically simple –composite test samples by Melis Engineering Ltd. on three HQ diameter metallurgical drill holes from both deposits show 98% uranium leach extraction under relatively mild atmospheric conditions.
  19. 19. Horseshoe and Raven deposits HU-16 high grade intercept = 12.35 m @ 4.53% U3O8 2.29 % 0.95 % 22.17 % 8.14 % Nodular pitchblende Pitchblende in Late yellow boltwoodite-rimmed by boltwoodite hematite-clay uranophane
  20. 20. Horseshoe and Raven deposits Nodular/veinlet style, Horseshoe A zone2.29 % Mineralization comprising hematite- p pitchblende bands which cross cut gneissosity at high angle: shallow dipping morphology to zones. Examples from HU-28 (191 8-193 4 m = (191.8-193.4 2.55% U3O8 over 1.6 m)
  21. 21. Horseshoe and Raven deposits Horseshoe disseminated mineralization textures, B east zone ,Hole HU-063: Interval shown is 348-357 m, typical of broad low grade m interval of 60.90 m grading 0.18 % U3O8 from 322.40-383.3 m. Note competent nature of host rocks in zone.
  22. 22. Horseshoe Section 4640N Horseshoe and Raven deposits
  23. 23. Horseshoe and Raven deposits Horseshoe Section 4724N - Zones may belocalized around al li d d pre-mineral fault zone - Shallow dippingmineralized zonesmay be extensional and f d formed i d in response to late reverse faulting
  24. 24. Horseshoe and Raven depositsMineralogy calculatedfrom multielementgeochem. Alteration-geochem zoning (S. Halley, 2008) Normative mineralogical assemblages show illite core with surrounding chlorite- dominant fringe Terraspec patterns show Mg-rich Chlorite 2250nm chlorites i mineralization and alteration; hl i in i li i d l i wavelength ranges = Mg-rich chlorites raw Mg-geochemistry shows same proximal to pattern cutting lithologic sequence mineralization, 4640N.
  25. 25. Horseshoe Horseshoe and Raven deposits wireframe models Mineralization plunges to east-northeast Eastern margin of g Horseshoe wireframe o ses oe e a e orebody is parallel and view NNE with drill adjacent to the Dragon holes shown Lake Fault. Alteration in the orebody is contiguous with intense alteration that extends to >600 m t d t 600 depth along the fault. Horseshoe wireframe view SSE from above
  26. 26. Horseshoe and Raven deposits Raven R Raven wireframe View southwest from Horseshoe models Horseshoe towards Raven with drill hole traces Raven Raven view ENE view NNE Horizontal zone: no plunge. Basal planar (L) zone (in red) dips southeast, with shallower dipping zones above reaching to 60 m from surface
  27. 27. Raven mineralization Horseshoe and Raven depositsMineralization discordant to foliationin drill hole RU-118 from interval at RU 118,118.2 m grading 0.63% (in interval = 19.8 m @0.517% U3O8) RU-026 mineralization, 118-124 m. Concordant mineralization style in interval of 2.98% U3O8 / 5.2 m) RU-095 mineralization, 148 149 m. 148-149 m From interval 0.38% RU-002 , 106.5 m, 0.4 m at 2.13% U3O8 U3O8 over 37.3 m
  28. 28. Raven Horseshoe and Raven deposits section 5445E Like Horseshoe, mineralization surrounds a clay alteration zone Lithologies thinner: mineralization 0 5 4 L R U R B 8 0 L - 6 U R 4 3 0 - U R 2 0 L - U R B 6 1 L 4 0 - 2 7 0 9 6 m 0 5 L B 0 L - 0 4 L R m 0 5 0 5 5 m m 0 5 m 0 m 0 5 m 0 5 m 0 5 0 5 3 L R 0 1 0 1 0 1 0 1 0 1 0 1 0 0 1 0 1 extends to 5 1 0 0 5 1 0 5 1 0 0 0 3 0 2 L R 0 0 2 0 5 1 m . 2 9 1 0 5 1 0 5 1 0 5 1 0 5 1 0 5 2 m1 .2 6 3 25 8 L R m 1 m 1 . 0 2 0 2 0 2 0 2 0 2 m 9 3 2 0 5 m . 8 1 2 0 2 L R m 7 . 4 9 2 0 5 2 0 5 2 0 5 1 L R 0 3 0 0 3 m 1 3 s a o e depths shallower dept s than Horseshoe into calc-arkose Upper, thick p pp , parts of orebody within 100 m of surface may be amenable to open pit mining.
  29. 29. Raven section 5630E Horseshoe and Raven deposits 0 5 4 L R U R B 8 0 L - 6 U R 4 3 0 - U R 2 0 L - U R B 6 1 L 4 0 - 2 7 0 9 6 m 0 5 L B 0 L - 0 4 L R m 0 5 0 5 m 5 m 0 5 m 0 5 m 0 5 0 5 3 L R 0 1 0 1 0 1 1 0 0 1 5 1 0 5 1 0 5 1 0 0 0 3 L R 0 2 0 5 1 0 5 1 2 0 5 1 m . 2 9 0 5 1 0 5 1 0 5 1 0 5 2 5 8 1 L R m 1 2 . 6 3 m 1 .2 0 0 2 0 2 2 0 2 0 2 m 9 3 2 0 5 2 m . 8 1 0 2 L R m 7 . 4 9 2 0 5 2 0 5 2 0 5 1 L R 0 3 0 0 3 m 1 3 Mineralization locally exploits lithologies and lithologic contacts above a steep SE dipping basal zone and alteration
  30. 30. Horseshoe and Raven deposits Conclusions UEX successfully upgraded and expanded resources in the Horseshoe and Raven deposits, increasing the deposit footprint and establishing continuity of mineralization The deposits are remarkable for their great extent into basement rocks, but with no association with graphitic faults. Geophysical target is alteration – not graphite. Si il iti t Kiggavik? t t i lt ti t hit Similarities to Ki ik? Basement – basin fluid mixing and redox reaction along Dragon Lake and pre-mineralization hosting fault zones, and reaction with p g reduced wallrocks may have contributed to mineralization formation “Basement” signature geochemistry of mineralization: favorable metallurgy without deleterious elements, similar mineralogy to elements Eagle Point Occurrence of mineralization in competent hematite alteration within basement wallrocks allows good geotechnical conditions for open pit and ramp access underground mining (i.e. no ground freezing)
  31. 31. Horseshoe and Raven deposits Advancing the Horseshoe and Raven deposits g p In anticipation of feasibility, initial metallurgical, g p y g geotechnical and environmental baseline studies have been undertaken High proportion of resources already in indicated category Scoping study underway examining mining methods and options underway, for both deposits, including possible future use of any open pit developed at Raven or Horseshoe as a regional tailings facility for other deposits in the area Area of excellent existing mining and milling infrastructure: Potential for toll milling at Rabbit or McClean Lake is being assessed. Additional targets in local area will be tested in 2011 which could e pa d oca esou ce expand local resource base

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