Geochemical Characteristics And Genesis Of Uranium Bearing Granite Of Baru Malakand Area Pakistan

The Malakand granite of the Permian age in north Pakistan includes the Baru anomalous zone which is the most promising as it is uranium rich and almost thorium free granite with sporadic occurrences of uraninite grains along with quartz and fluorite.This thesis comprised the detailed field investigation of the prospect,the indoor identification of rock and minerals,petrography and elemental geochemistry analysis,and obtained the following main understanding:(1)The data obtained revealed that the Baru anomalous zone consists of six radioactive zones with variable dimensions and spread over in an area of 3000 m x 500 m.The Malakand granites consists of the granite,quartz rich granitiods and alkali feldspar granite.(2)Major elements,trace elements and Rare Earth Elements(REE)analysis revealed that studied granites display sub-alkalic character with calc-alkaline affinity on Si O₂-K₂O plot.Rare earth elements spider plot normalized to chondrite meteorite shows high LREE(Light Rare Earth Elements)content compared to Heavy Rare Earth Elements(HREE)and hence,greater LREE/HREE ratio with weakly positive and negative Ce and Nd anomalies respectively.Its geochemistry suggests that it is strongly peraluminous and and hence S-type in character.(3)The Electron Probe Micro Analalyzer(EPMA)analyses identified the Uranium(U) minerals including coffinite and uraninite.The uraninite host major U&Thorium(Th)budget having low High Field Strength Elements(HFSE)and HREE.Conversely,Coffinite is major sink for titanium(Ti),niobium(Nb),tantalum(Ta),yttrium(Y)and ytterbium(Yb)having comparatively low concentration of U and Th.Uraninite grains in granitic pegmatites,are usually associated with biotite,rutile,monazite,zircon,galena,xenotime and calcite.While coffinite grains are associated with uraninite,calcite,galena and pyrite.(4)The uranium mineralization is associated with medium and fine-grained granite gneiss,which is highly fractured and sheared.The mineralized fractures are either in the form of a single fracture or group of fractures showing convergence and divergence in the subsurface.