Browsing by Author "Mammo, Telahun"

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    The Geology Geochemistry and Origin of Supplied Mineralization in Katta,Wollega Province
    (Addis Ababa University, 1980-07) Mammo, Telahun; Valera, Roberto (Prof.)
    The Katta rocks form part of the Birbir group of the upper compl ex s i tuated in the paleo- cal c-alkaline arc that runs northsouth across the country and which compri ses thick sequences of metavolcanic and metasedimen tary r ocks 0 The rocks are intensel y folded and faulted o Their minera l ogy and texture indicate that metamorphism is o f the greenschist facies o Logging of five bore ho l es , their correlation and subs equerr petrographic s tudies on selected samples are conducted and depth variation i n miner a logy i s presented o Geochemical studies on stre am sedime nt s , bed r ock and f l oat samples, soil and core samples , and statistical tr eatment, of the results show that there is lateral and vertical variati ons in the copper and zinc mineralizations . The geochemical s oil maps show that Cu , Zn , Pb , Ni , and Co mineralizations are concentr ated along fo liation and bedding p laneso There is low litho logical c ontro l of mi neralization o Moda l ana l ysis on the core samples s how that main mineralization is a s sociated to carbonate o Ore microscopic studies show that pyrite , chalco pyrite , magnetite , bornite , cubanite) bournonite , cuprite and sphal e r ite are the ore minerals found occuring in bands , as d i ss eminati ons and in veins o Two types of mineralization are recognized syngenetic stratabound and e pigene t ic vein and dissemina t ed types . It was the syn~enetic type that gave rise to epigenetic types as a resul t of later met a morphi(: and supergene remobilization. 'r'he epigenetic type is considered to be the main mineralization in the area o