Uranium Minerals in the Granitic Rocks

Uranium minerals in the granitic rocks

By Prof.Dr.\ Medhat El-Mansi Professor of Petrology and Mineralogy Egyptian Nuclear Materials Authority PetrographicPetrographic characteristicscharacteristics

ofof thethe

uranium-mineralized granites Granite Textures and mineralogy Classification of uranium deposits Intrusive and metasomatic MainUranium topics minerals Oxides, silicates, phosphates, vanadates and carbonates Uranium-mineralized granites

Petrographic characteristics of the Uranium- mineralized granites Granite • Granite belongs to the acidic rocks that

having more than 66% SiO2 which is, expressed by high modal quartz (20% or more of the felsic fraction). • The colour index is less than 10 in typical granites. Granite contains alkali feldspar > 35% total feldspar. • The majority of granites are medium to coarse grained, their major contents are subhedral. TheThe commoncommon texturestextures are:are: perthitic K-feldsparsK-feldspars porphyriticporphyritic(microcline(microcline oror orthoclase)orthoclase) enclosing intergrown albite formed by LargeLargeenclosing phenocrystsphenocrysts intergrownRapakiviRapakivi ofof orthoclaseorthoclase albite formed oror by exsolution.exsolution. •microclinemicroclineK-feldsparK-feldspargraphicgraphic (bothphenocrysts(bothphenocrysts oror typically typicallymicrographicmicrographic encasedencased perthitic).perthitic). inin oligoclaseoligoclase.. • IntergrowthFormedIntergrowthFormed asas aa resultresultbetweenbetweenMyrmikiticMyrmikitic ofof reaction reactionaa singlesingle betweenK-feldsparbetweenK-feldspar thethe partiallypartially crystalcrystal crystallizedcrystallized andand enclosedenclosed magmamagma smallsmall andand skeletalskeletal thethe grainsgrains ThisThis intergrowthintergrowthGneissoseGneissose isis closelyclosely similarsimilar toto thethe adjacentadjacentofof quartz.quartz. peliticpelitic rocks.rocks. graphicgraphic intergrowthintergrowth butbut itit isis post magmatic •AtAt CharacterizesCharacterizes thethe marginsmargins ofofgranite,granite, thethe plutonpluton whichwhich duedue isis thethetoto shearingshearing typicaltypical and even of metasomatic origin.. duringduringfinalfinal productproduct emplacementemplacement ofof differentiation.. in the upper levels of the layered basic intrusions.. MineralogyMineralogy ofof granitesgranites EssentialEssential mineralsminerals Alkali feldspars Plagioclase Quartz Mostly perthitic Maficorthoclase minerals and microcline. Perthite could be seen in ordinary light due to Biotite Muscovite and Li-micas selective alteration of their potassic and sodic Calc-alkaline granite peraluminous granite phases. 20-40%Hornblende of the rock, mostlyhastingsite, anhedral riebeckite and containing inclusions suchand asarfvedsonite apatite and zircon. It may show undulatory extinction. Calc-alkaline granite Alkali granite MineralogyMineralogy ofof granitesgranites AccessoryAccessory mineralsminerals

apatite sphene Apatite. zircon c e d i t e t i magnetite i e t l n t l a i e a t e n n r Sphene. i i a g n m

r m i a a l g r a d a t g a k n Zircon. l o a c Magnetite.. Granite

Classification of the uranium deposits Classification of uranium deposits (Young, 1988) Sedimentary Quartz-pebble conglomerateEffusive (Elliot Lake - Canada) BlackSialic volcanicsshale Intrusive (Chattanooga (Pena Blanca Shale -- Mexico)U.S.A.) MudsPeralkalineMafic volcanics nepheline Metasomatic syenites (Olympic (Walvis(Ilimaussaq- Dam Bay - - Greenland) Australia)Namibia) ContactCarbonatites Metamorphic (Mary Kathleen-Australia) (Araxa - Brazil) Phosphorites (Western U.S.A.) SodicAnatecticsPhyllites Uncertain (Ukranian (Vein like) (Forstau(Rossing Shield - - - Australia) Namibia)Ukrania) Bauxites (Arkansas - U.S.A.) Unconformity-relatedEpigenetic (Rabbit Lake - Canada) GranitesSchists (Spokane Mountain (Portugal) - U.S.A.) Placers (Southeastern U.S.A.) Vein-likeSandstones in metamorphic (Beaverlodge (Gas Hills -- U.S.A.)Canada) Pegmatitic alkalitic granites (Bokan Mountain - U.S.A.) BrinesCalcretes (Yeelirrie -(Sea Australia) water) Vein-like in sediments (Orphan mine - U.S.A.) PegmatitesLimestones (Bancroft (Todilto - -Canada) U.S.A) Phosphates (Baukoma - Zaire) Hydrothermal veins (Schwartzwalder - U.S.A.) Classification of uranium deposits (Young, 1988) Sedimentary Effusive Intrusive Metasomatic Metamorphic Uncertain (Vein like) Epigenetic Granite Classification of the uranium deposits

Uranium minerals Uranium minerals Oxides Silicates Phosphates Vanadates Carbonates Uranium minerals Oxides Silicates Phosphates Vanadates Carbonates Zoom

Pitchblende

Pitchblende Pitchblende Zoom

Uraninite UO2-X(0.0

UO2-X(0.0

Rotation

UO2-X(0.0

K2(UO2)2(SiO3OH)2.5H2O Boltwoodite

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U(SiO4)1-X(OH)4X Coffinite

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(H3O)2Cu(UO2)2(SiO4)2.4H2O Cuprosklodowskite

(H3O)2Ca(UO2)2(SiO4)2.3H2O Uranophane Zoom

(H3O)2Ca(UO2)2(SiO4)2.3H2O Uranophane

(UO2)2SiO4.2H2O Soddyite Pb2(UO2)2(SiO4)2.2H2O Kasolite Uranium minerals Oxides Silicates Phosphates Vanadates Carbonates UV

R1-2(UO2)2(TO4)2.8-12H2O Autunite

Zoom UV

R (UO ) (TO ) .6-8H O 1-2 2 2 4 2 2 Meta autunite

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Fe Al (UO ) (PO ) (SO )(OH) .20H O 2 2 2 2 4 2 4 2 2 Coconinoite

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(U,Ca,Ce)2 (PO4)2.1-2H2O Ningyoite

Cu(UO2)2(PO4)2.8-12H2O Torbernite Zoom

Ca2 (UO2)3(PO4)2(OH)4.4H2O Phurcalite

Ba (UO2)2(PO4)2.12H2O Uranocircite

Uranium minerals Oxides Silicates Phosphates Vanadates Carbonates Zoom

K2(UO2)2V2O8.3H2O Carnotite

Zoom

Ca(UO2)2V2O8.8H2O Tyuyamunite

Uranium minerals Oxides Silicates Phosphates Vanadates Carbonates UV

Na2Ca(UO2)(CO3)3.6H2O Andersonite

Zoom UV

Ca2(UO2)(CO3)3.11H2O Liebigite

Under the ore microscope Under the ore microscope CHP

Uraninite (U), Pyrite (P) and chalcopyrite (CHP). Tyndrum, Scotland Under the ore microscope

CHP G

Uraninite (U), galena (G) and chalcopyrite (CHP). Tyndrum, Scotland Under the ore microscope CHP

Uraninite (U) and chalcopyrite (CHP). Tyndrum, Scotland Under the ore microscope

CHP U

Uraninite (U) and chalcopyrite (CHP). Port Radium, Canada Under the ore microscope Carbonates Botryoidal, collomorphic uraninite encloses a U rhombic carbonate CHP

Uraninite (U) and chalcopyrite (CHP). Port Radium, Canada Under the ore microscope

CAR U

CHP

Uraninite (U), carbonaceous matter (CAR) and chalcopyrite (CHP). Canada Under the binocular microscope MonaziteMonazite crystalscrystals fromfrom El-ErediyaEl-Erediya granite.granite. Uranophane Under the polarizing microscope A B

C D A B

C D Granite Classification of the uranium deposits Uranium minerals

Uranium-mineralized granites GeneralGeneral viewview ofof granitegranite GeneralGeneral viewview ofof granitegranite ‘

UranophaneUranophane ApatiteApatite inin quartz.quartz. PetrographicCONCLUSIONS characteristics of the Uranium mineralized granites The petrographic characteristics of the uranium-mineralized granites The abundance of microfractures that are generally filled with iron oxides, quartz, fluorite and sometimes calcite. FractureFracture filledfilled withwith calcitecalcite inin El-MissikatEl-Missikat granite.granite. FractureFracture filledfilled withwith calcitecalcite inin El-MissikatEl-Missikat granite.granite. Fracture filled with quartz and iron oxides in El-Missikat granite. Fracture filled with iron oxides in El-Missikat granite. The petrographic characteristics of the uranium-mineralized granites The abundance of microfractures that are generally filled with iron oxides, quartz, fluorite and sometimes calcite. The common presence of multicolored fluorite crystals, especially the violet and purple variety Cavity filled with fluorite in El-Erediya granite Colorless fluorite from El-Missikat granite. Violet fluorite from El-Missikat granite. Blue-Violet fluorite from El-Missikat granite. The petrographic characteristics of the uranium-mineralized granites The abundance of microfractures that are generally filled with iron oxides, quartz, fluorite and sometimes calcite. The common presence of multicolored fluorite crystals, especially the violet and purple variety

The common presence of pleochroic haloes in micas especially around some radioactive included crystals (e.g. monazite, thorite, allanite, zircon,.. etc). Pleochroic halos in biotite in Gattar granite. Pleochroic halos in biotite in El-Missikat granite. Pleochroic halos in biotite in El-Missikat granite. Pleochroic halos in biotite in El-Erediya granite. Pleochroic halos in biotite in El-Erediya granite. The petrographic characteristics of the uranium-mineralized granites The abundance of microfractures that are generally filled with iron oxides, quartz, fluorite and sometimes calcite. The common presence of multicolored fluorite crystals, especially the violet and purple variety The common presence of pleochroic haloes in micas especially around some radioactive included crystals (e.g. monazite, thorite, allanite, zircon,.. etc). The presence of monazite, allanite and zircon crystals especially those coated with iron oxides and metamicted Zircon crystals highly stained with iron oxides, El-Missikat granite. Zircon crystals highly stained with iron oxides, El-Missikat granite. The petrographic characteristics of the uranium-mineralized granites The abundance of microfractures that are generally filled with iron oxides, quartz, fluorite and sometimes calcite. The common presence of multicolored fluorite crystals, especially the violet and purple variety The common presence of pleochroic haloes in micas especially around some radioactive included crystals (e.g. monazite, thorite, allanite, zircon,.. etc). The presence of monazite, allanite and zircon crystals especially those coated with iron oxides and metamicted The wide spread alteration processes such as the silicification, ferrugination, kaolinization, epidotization, greisenization and carbonatization especially in granites associating the vein type uranium deposits as well as the amazonitization and/or albitization in those associating the metasomatic type uranium deposits. Microcrystalline quartz and amorphous silica in silicified granite, El-Missikat granite. Microcrystalline quartz and amorphous silica in intensively silicified granite, El-Missikat granite. C Q

CalciteCalcite (C)(C) andand QuartzQuartz (Q)(Q) fillingfilling fracturefracture inin El-MissikatEl-Missikat granite.granite. Q C

CavityCavity filledfilled withwith CalciteCalcite (C)(C) andand QuartzQuartz (Q)(Q) inin El-El- MissikatMissikat granite.granite. Epidote

Fan-shapedFan-shaped epidoteepidote inin epidotizedepidotized granite,granite, P.L.,P.L., El-MissikatEl-Missikat granite.granite. Epidote

Fan-shapedFan-shaped epidoteepidote inin epidotizedepidotized granite,granite, C.N.,C.N., El-El- MissikatMissikat granitegranite.. Kaolinized plagioclase in Gattar granite. Intensively kaolinized granite, El-Missikat granite Chloritized biotite in El-Erediya granite. Intensively ferruginated granite, El-Erediya granite The petrographic characteristics of the uranium-mineralized granites 1- The abundance of microfractures that are generally filled with iron oxides, quartz, fluorite and sometimes calcite.

2- The common presence of multicolored fluorite crystals, especially the violet and purple variety.

3- The common presence of pleochroic haloes in micas especially around some radioactive included crystals (e.g. monazite, thorite, allanite, zircon,.. etc).

4- The presence of monazite, allanite and zircon crystals especially those coated with iron oxides and metamicted.

5- The wide spread alteration processes such as the silicification, ferrugination, kaolinization, epidotization, greisenization and carbonatization especially in granites associating the vein type uranium deposits as well as the amazonitization and/or albitization in those associating the metasomatic type uranium deposits. The petrographic characteristics of theThank uranium-mineralized you for your attention granites 1- The abundance of microfractures that are generally filled with iron oxides, quartz, fluorite and sometimes calcite.

2- The common presence of multicolored fluorite crystals, especially the violet and purple variety.

3- The common presence of pleochroic haloes in micas especially Thankaround some you radioactive for included your crystals attention (e.g. monazite, thorite, allanite, zircon,..Thank etc). you

4- The presence of monazite, allanite and zircon crystals especially those coated with iron oxides and metamicted.