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Training and education in uranium Training and education in uranium geology and explorationgeology and exploration

Michel CUNEYMichel CUNEY

Phurcalite

NANCY UNIVERSITE NANCY UNIVERSITE -- UMR G2R UMR G2R –– CREGU CREGU –– CNRSCNRS54 506, 54 506, VandoeuvreVandoeuvre les NANCYles NANCY

FRANCEFRANCEURAM 2009 – IAEA – VIENNA – June 25th 2009

Evolution of the scientific research in U metallogenesis and training closely follows the evolution of exploration budgets :� themselves being a direct consequence of the metal price on the market1970’s : Strong increase of exploration, consequence of the 1973 oil crisis, end of 1980’s to early 2000’s sudies and training related to U metallogenesisalmost stopped in most countries> 1990 : opening of the Soviet block countries, � huge research effort developed by USSR since 1945 became accessible :� USSR had mined almost half of the U produced in 1990,� partly from deposits not known to have large resources in the W. countries� several hundreds of deposits have been added to the IAEA data base

> 2008 : the number of publications on U deposits will become exponentialin relation with the explosion of exploration budgets, research in the universities, project development in large companies and junior companies following the strong increase of the U prices on the spot market.

History of training & education in uranium geology & exploration

From Kyser and Cuney 2008

Development of R & D studies with the evolution of U spot price

As a result of the weak exploration & research efforts during the last 20 years: � skilled professionals in the field of U geology and exploration have tremendously decreased �U explor. companies have faced a severe lack of experienced geologists� Retired U geologists have massively returned to work in the junior companies and as consultants� Training programs are developed worldwide, but needs are tremendous� Presently, the best training are made for radioprotection because of the strong existing regulations. � A considerable effort has to be made for developing the education in the physical & geochemical properties of U, very specific to this element, and for the understanding of the multiple geologic models of U-deposits�Such knowledge is required to develop efficient exploration programs and to prevent spending large investments for hopeless targets as illustrated by many case studies.

History of training & education in uranium geology & exploration

From Marlatt 2006

Increasing R & D and training are required to sustain exploration

1973. Pagelfirst discoveryof the brines 2007

first determinationof the U contentin the brines

1975

The Key Lake discovery demonstrated that the “unconformity model”can explain the ATHABASCA uranium deposits

Major lines of education & training in U geology & exploration1 – Uranium has specific properties mainly due to its radioactivity andredox compared to other metals which have major implications :� in exploration� in safety issues

2 – U deposits occur in extremely diverse geologic settings all aroundthe geological cycle � needs of a comprehensive education in geology3 – The knowledge of the ways to evaluate the quality of the U sources to estimate area favourabilty for U exploration is outmost Importance,the knowledge of traps is of second order priority, and then the vectors4 – The uranium hosting phases are very diverse : the knowledge of theirnature is critical for the economics of the ore processing5 – geophysical techniques Increasingly sophisticated will be needed forthe discovery of deeper and deeper deposits6 – Development of integrated GIS based exploration techniques

URAM 2009 – IAEA – VIENNA – June 25th 2009

Major lines of education & training in U geology & exploration1a – Uranium has specific physical properties especially itsradioactivity, compared to other metals which have major implications :

� in exploration :� Gamma scintillometers, spectrometers� Heat flow/heat production � U provinces� Age determinations :

- U-Pb isotopic Concordia diagrams- U-Pb chemical ages (1% PbO = 100 Ma)- U decay series (> 1Ma)- Spontaneous fission (U-Xe & U-Kr ages / fission tracks)

� Equilibrium vs disequilibrium� Metamictization of U minerals� Destruction rims/pleochroic haloes/coloration of minerals� 4He, Radon emanations� Radiolysis of water � secondary oxidation, H2 emission

� in safety issues : will not be developed hereURAM 2009 – IAEA – VIENNA – June 25th 2009

Major lines of education & training in U geology & exploration2a - Uranium has specific chemical properties :

� U is highly mobile in the oxidized state as uranyl complexes� U has an extremely low solubility in reduced conditions

(more than 10 orders of magnitude for crystallized phases )equivalent to the solubility of ThO2

� redox is the major control on U-mobilization & depositionfor most U deposits (except calcretes, quartz pebble conglomerates, …)� Strong relation with organic matter from very low to high T� Uranyl ions form more than 40 complexes with variable pH

and ligands concentrations


NaUO2(OH)5)(s)

log [U

, Th]

pH2 4 6 8 10 12

-16

-14

-12

-10

-8

-6

-4

-2

ThO2(am)

ThO2(cr)

U O2 (cr)

U(OH)4(am)UO2 (OH)2 (s)

UO2 (am)

S choepite

S oddyite

Carnotite

Sea water : 3.3 ppb

M e ta s c h

o e pi t e

NaUO2(OH)5)(s)

log [U

, Th]

pH2 4 6 8 10 12

-16

-14

-12

-10

-8

-6

-4

-2

ThO2(am)

ThO2(cr)

U O2 (cr)

U(OH)4(am)UO2 (OH)2 (s)

UO2 (am)

S choepite

S oddyite

Carnotite

Sea water : 3.3 ppb

M e ta s c h

o e pi t eUranium and

thorium solubilityat 20°CUO2, ThO2 / UO2

2+

Carnotite/metaschoepite


OkloOklo DepositsDeposits & Natural & Natural NuclearNuclear ReactorsReactors, Gabon, Gabon

100 m

W E

Okelobondo

Okloopen pit151-2

3-67-9

13

10-16

OK84bis

FA sandstone

reactionzones

mineralizedC1 layer

FB Ampelites

Cristallinebasement

First depositon the Earthcontrolled byredox Reactionsat 2 Ga

Se U, V Mo


The The rolerole of REDOXof REDOX

Major lines of education & training in U geology & exploration

2 – U deposits occur in extremely diverse geologic settingsall around the geological cycle� needs of a comprehensive education in all fieldsof geology, except may be in ultrabasic magmatism !


Total > 1,200 deposits (Total > 1,200 deposits (UDEPO data baseUDEPO data base) ranked into > 9 types:) ranked into > 9 types:1) 1) UnconformityUnconformity--relatedrelated (47)(47) : : Mac Arthur, Mac Arthur, CigarCigar Lake, Ranger, Lake, Ranger, JabilukaJabiluka2) 2) SandstonesSandstones (346) (346) : : ArlitArlit,, Akouta, Akouta, MynkudukMynkuduk, Colorado plateau, Colorado plateau3) 3) HematiteHematite brecciabreccia complexes (7)complexes (7) : : OlympicOlympic DamDam4) Quartz4) Quartz--pebblepebble conglomeratesconglomerates (27) (27) : Witwatersrand basin, Elliot Lake: Witwatersrand basin, Elliot Lake5) 5) VeinsVeins (53)(53) : : SinghbhumSinghbhum, , PribamPribam, , BernardanBernardan, , 6) Intrusive (21) 6) Intrusive (21) : : RRöössingssing7) 7) VolcanicVolcanic and calderaand caldera--relatedrelated (174)(174) : : StreltsovskStreltsovsk, , DornotDornot, , XiangshanXiangshan, , McDermittMcDermitt8) 8) MetasomatitesMetasomatites (24)(24) : : : : MichurinskoyeMichurinskoye, , LagoaLagoa Real, Real, ArjeplogArjeplog9) 9) OthersOthers (159)(159)

surficialsurficial : : YeelirieYeelirie, Langer Heinrich, Langer Heinrichcollapse collapse brecciabreccia pipes (11)pipes (11) : Grand Canyon: Grand Canyon--Arizona Arizona StripStripphosphorites (17)phosphorites (17) : : GantourGantour, Al, Al--AbiadAbiad, , UncleUncle Sam, Sam, MelovoeMelovoemetamorphicmetamorphic (10) (10) : : ForstauForstau, Mary Kathleen, , Mary Kathleen, limestoneslimestones (?)(?) : Grants: Grantscoalcoal (8)(8) : Serres, Dakota, : Serres, Dakota, NizhneNizhne, , FreitalFreitalblack shalesblack shales : : ChatanoogaChatanooga, , ChanzipingChanziping, , RandstadtRandstadt, Padma, Padmaunknownunknown

IAEA classification of uranium deposit types IAEA classification of uranium deposit types

Weaknesses of the IAEA classificationWeaknesses of the IAEA classificationMainly based on the nature of the host rock lithology :

- easy to apply,- BUT may lead to strong misunderstanding of the nature

of the exploration targets- because do not take into account the ore forming processes

Exemple : type 6INTRUSIVE TYPE : disseminated mineralization in intrusive rocks

in fact regroups 2 very different types of mineralization :- U deposits related to partial melting (ex. Rössing)- U deposits related to fractional crystallization (ex. Ilimaussaq)

U deposits related to partial melting :� Always occurs in high-grade migmatiticdomains with limited partial melting� Do not originate from a deeper granitic body, but rather merging of granitic dikesto form small granitic lenticular bodies.� Uraninite main ore mineral

U depos. related to crystal fractionation :Located in the apical & most differentiatedpart of the peralkaline plutonic complexes� High structural level� Complex and highly refractory U oreminerals

Cross section of the Rössing deposit

Cross section of a peralkaline syst.

SEDIMENTARYROCKS

Volcanic Calcretes/lignite/coalPhosphates

Black shalesRollfrontTabularTectonolithologic

Unconformity

Magmatic(crystal fract.)

M A N T L E

Conglomerates

IOCG(U)

SEDIMENTARYROCKS

T °C

HTMetamorphic

Na-metasomatism

100100

200

300400

600

25

METAMORPHICROCKS

IGNEOUSROCKS

Breccia Pipes

800

CONTINENTALCRUST1.7ppm U

HKCa

AlaskitesPAl

Upper cont. crust2.7 ppm U

Primitive Mantle : 21ppbCarb. chondrites : 7ppb

Veins

PAk

BasalPAk

PAl

HKCa

LTMetamorphic

SEDIMENTARYROCKS

Volcanic Calcretes/lignite/coalPhosphates

Black shalesRollfrontTabularTectonolithologic

Unconformity

Magmatic(crystal fract.)

M A N T L E

Conglomerates

IOCG(U)

SEDIMENTARYROCKS

T °C

HTMetamorphic

Na-metasomatism

100100

200

300400

600

25

METAMORPHICROCKS

IGNEOUSROCKS

Breccia Pipes

800

CONTINENTALCRUST1.7ppm U

HKCa

AlaskitesPAl

Upper cont. crust2.7 ppm U

Primitive Mantle : 21ppbCarb. chondrites : 7ppb

Veins

PAk

BasalPAk

PAl

HKCa

LTMetamorphic


A GENETICA GENETICCLASSIFICATIONCLASSIFICATIONOF UOF U--DEPOSITSDEPOSITS

�� 1 1 –– FFractionalractional crystallizationcrystallization: : IlimausacqIlimausacq, , BokanBokan MountainMountain�� 2 2 –– Partial Partial meltingmelting: : RRöössingssing�� 3 3 –– Hydrothermal Hydrothermal highhigh levellevel postpost--orogenicorogenic ::�� 3A 3A –– VolcanicVolcanic -- hydrothermal (hydrothermal (StreltsovskaStreltsovska))�� 3B 3B –– GraniticGranitic -- hydrothermal (French hydrothermal (French VariscanVariscan, Erzgebirge), Erzgebirge)

�� 4 4 –– Diagenetic hydrothermal Diagenetic hydrothermal systemssystems::�� 4C: 4C: IntraformationalIntraformational redox controlredox control�� 4C1: 4C1: TabularTabular: Grants : Grants MineralMineral BeltBelt, , BevereleyBevereley HillsHills�� 4C2: 4C2: TectonolithologicTectonolithologic: Akouta, Niger: Akouta, Niger�� 4C3 : Karsts (4C3 : Karsts (becciabeccia pipes): Coloradopipes): Colorado

�� 4A: Basin/4A: Basin/basementbasement redox control (redox control (unconformityunconformity relatedrelated))�� 4B: 4B: InterformationalInterformational redox control (redox control (OkloOklo, Gabon), Gabon)

�� 5 5 -- Hydrothermal Hydrothermal metamorphicmetamorphic: : ShinkolobweShinkolobwe, , MistamiskMistamisk�� 6 6 –– Hydrothermal Hydrothermal metasomaticmetasomatic: : �� 6A 6A –– AlkaliAlkali--metasomatismmetasomatism : : LagoaLagoa Real, Real, KrivoiKrivoi RogRog�� 6B 6B –– SkarnsSkarns :Mary :Mary KatheleenKatheleen -- TranomaroTranomaro (Madagascar)(Madagascar)

�� 7 7 –– SynSyn--sedimentarysedimentary::�� 7A: 7A: MechanicalMechanical sortingsorting: : QzQz pebblepebble conglomeratesconglomerates: Witwatersrand, Elliot Lake: Witwatersrand, Elliot Lake�� 7B: Redox 7B: Redox trappingtrapping: black shales, : black shales, AlumAlum shales shales SwedenSweden (marine & continental)(marine & continental)�� 7C: Crystal7C: Crystal--chemicalchemical/redox /redox trappingtrapping: phosphates : Maroc: phosphates : Maroc

�� 8 8 -- IntraformationalIntraformational meteoricmeteoric fluidfluid infiltrationinfiltration�� 8A:8A: SealedSealed paleovalleyspaleovalleys: Vitim (: Vitim (TransbaikaliaTransbaikalia))�� 8B:8B: Roll fronts: Powder River Basin (Wyoming)Roll fronts: Powder River Basin (Wyoming)

�� 9 9 ––-- WeatheringWeathering & & evapotranspirationevapotranspiration: calcretes: : calcretes: YeleerieYeleerie�� 10 10 –– OtherOther typestypes : : brecciabreccia complexcomplex ((OlympicOlympic Dam)Dam)

Major lines of education & training in U geology & exploration

3 – The knowledge of the ways to evaluate the quality of the U sourcesto estimate area favourabilty for U exploration is outmost Importance,(large volumes � strategic exploration)

the knowledge of traps is also very cruxial after the source, (generally more localized)and then the vectors which may particularly complex and rarely easyto evidence


DEPOSITIONU U

MetalsLigandsFluidsMagmasEnergy

TRAPSstructuralchimicalmixing

TRANSPORTf l ui d

magma

SOURCESPartialmeltingU U

U

U

Hydrothermalleaching

TPXpHfO2

UU

Exogenic factors

Geod

ynam

ic Ré

gime

Chrno

therm

ométr

icEv

ol.

T P

Regional: x 100 kmScalesDistrict: x 10 km

Deposit: x km

Veindisseminated

Parameters ivolved in the genesis of an uranium deposit

THE URANIUM SOURCESTHE URANIUM SOURCES�� AcidicAcidic magmaticmagmatic rocks are the rocks are the mostmost enrichedenriched in U, but in U, but

enrichmentenrichment dependsdepends of :of :�� The rate of partial The rate of partial meltingmelting of the of the mantlemantle and continental and continental crustcrust�� The variations The variations relatedrelated to the to the degreedegree of of enrichmentenrichment of the of the protolithprotolith

�� primitive primitive mantlemantle / / enrichedenriched mantlemantle / / depleteddepleted mantlemantle�� averageaverage crustcrust / U/ U--enrichedenriched crustcrust (U(U--richrich acidicacidic rocks, U rocks, U trappedtrapped in in reducedreduced

sedimentssediments))�� The The degreedegree of of crystalcrystal fractionationfractionation ……�� Epicontinental Epicontinental platformplatform sedimentssediments (major (major periodperiod : : LowerLower

PaleoproterozoicPaleoproterozoic))URAM 2009 – IAEA – VIENNA – June 25th 2009

1 .41 .00 .6 1 .81 0 0

1 0 1

1 0 2

1 0 3

1 0 4

1 0 5

Na+K/Al

Na2CO3NaCl

UOUO22 SOLUBILITY IN GRANITIC MELTSSOLUBILITY IN GRANITIC MELTS

U (ppm)in the

silicatemelt

Oxygen buffers

PERALUMINOUS PERALKALINE N i- NiOH.M .

Cu 2O- C u O


SURFACE WATERSMeteoric/Sea

DIAGENETICFLUIDS

MetamorphicFluids

SubductionFluids

Groundwaters

FormationwatersMIXING

Calcretes/Lignite/Coal

PhosphatesBlack shalesRollfront

TabularTectonolithologic

Unconformity

Conglomerates

Metamorphic HTNa-metasomatism

Breccia Pipes

Metamorphic LT

M ETAM ORPHI SM

DIAGENESIS

U deposits relatedto basins

MAGMATICFLUIDS

SilicateMelts

Crustal

Mantlemelting

SkarnsAlaskitesCrust PartialMelting

COLLISION

E X H U M A T I ON

-E X T E

N S I O N

U deposits relatedto metamorphism

Magmatic-Hydrothermal

Fluids

VolcanicU deposits related

to magmaticrocks Fract. Crystal. IOCG(U)

Veins

S UBDUCT I O

N

MAGM

ATIC

FRAC

TIONA

TION

MANTLE FLUIDS / MELTS

MIXING

SURFACE WATERSMeteoric/Sea

DIAGENETICFLUIDS

MetamorphicFluids

SubductionFluids

Groundwaters

FormationwatersMIXING

Calcretes/Lignite/Coal

PhosphatesBlack shalesRollfront

TabularTectonolithologic

Unconformity

Conglomerates

Metamorphic HTNa-metasomatism

Breccia Pipes

Metamorphic LT

M ETAM ORPHI SM

DIAGENESIS

U deposits relatedto basins

MAGMATICFLUIDS

SilicateMelts

Crustal

Mantlemelting

SkarnsAlaskitesCrust PartialMelting

COLLISION

E X H U M A T I ON

-E X T E

N S I O N

U deposits relatedto metamorphism

Magmatic-Hydrothermal

Fluids

VolcanicU deposits related

to magmaticrocks Fract. Crystal. IOCG(U)

Veins

S UBDUCT I O

N

MAGM

ATIC

FRAC

TIONA

TION

MANTLE FLUIDS / MELTS

MIXING


THE IMPORTANCE & COMPLEXITY OF MINERALIZING FLUIDS

Major lines of education & training in U geology & exploration4 – The uranium hosting phases are very diverse :

the knowledge of theirnature is critical for the economicsof the ore processing :

Easily soluble : U oxides, coffinite, hexavalent U mineralsModerately soluble : brannerite, nyngyoite, collophaneRefractory : U-Ti-Nb-Ta phases, zircon and zirconolsilicates …. typical of peralkaline plutonic complexes


CONCLUSIONS AND PERSPECTIVES�Most training programs were stopped in most countries fromabout 1985 to 2005

� Considerable needs in education and training in uranium geologyand exploration after about 20 years of very weak exploration and mining activities, except in a few places.

� Organization of International exchange of geologic information and mineral collections illustrating the major world deposit types isneed to homogenize the description of uranium deposits :

� ex. what is an episyenite ?� to what mineralogical – geochemical changes correspond

Na-metasomatic alteration related to U deposits ?

[email protected] jointly by :

Mineralogical Association of Canada (MAC)&

Society for Geology Applied to Mineral Deposits (SGA)

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