Desta, Zerihun (PhD)Seid, Mohammed2018-07-092023-11-092018-07-092023-11-092016-05http://10.90.10.223:4000/handle/123456789/7344Tantalum is the most important valuable raw-material in electronic, medical and chemical industries.The Kenticha rare-element granite pegmatite in the Neoproterozoic Adola Belt of southern Ethiopia, is a subhorizontal sheet-like structurally controlled intrusive body, is an important source of tantalite, niobite and beryl where tantalite is currently mined and exported globally. A little is known about the mineralogy, content of trace elements, ore forming and interplay processes, and mechanisms leading to tantalite-columbite mineralization in granite pegmatites. The aim of this work is to evaluate the geology and geochemistry of tantalite deposit in the primary ore zone of the Kenticha granite pegmatite to further elucidate the genesis of the tantalite deposit. An integrated approach of geological field work, rock and ore petrography, and whole-rock analysis by ICP-MS and ICP-AES using drill core data was used to achieve this aim. The Kenticha rare metal pegmatite deposit is controlled by major deep-seated normal faults striking in a N–S direction that allow the emplacement of the deposit bounded by the serpentinite to the hangingwall and granite to the footwall. The Kenticha peraluminous pegmatite deposit show zonal variations in mineralogical assemblage, tantalite concentration, and trace and rare earth elements content. Six distinct mineral assemblages and three main zones: border, intermediate and core zones were identified from literature analysis,field observation, petrographic study and whole-rock analysis. The tantalum and niobium concentration increase towards the core zone while the niobium concentration increase to border zone. The columbite group minerals (CGM) variation diagram shows progressive fractionation from ferroniobite to manganotantalite of primary magmatic fractionation with later hydrothermal-metasomatic alteration. It is strongly differentiated granitepegmatite enriched with Rb,Be, Nb, Ta and Csand depleted in V, Ba and Sr contents for whole–rock analyses of the Kenticha drill core samples. The rare earth element (REE) patterns of the primary ore zone shows slight enrichment in LREE with strong negative Eu-anomaly. From mineralogical assemblage, tectonic setting and geochemical signatures the genesis of Kenticha tantalite deposit is by partial melting of metasedimentary rocks predated the granite and pegmatite with later hydrothermal-metasomatic enrichment of tantalite in the area. Its formation and emplacement is related to the collision and felsic magmatism during post-Gondwana assemblyenPegmatite in the NeoproterozoicThesis