The study aimed at characterizing the geochemical compositions of Tarat Sandstones horst of uranium deposit in Arlit, Northern Niger. Induced Coupled Plasma - Atomic Emission Spectrometry (ICP-AES) and Induced Coupled Plasma-Mass Spectrometry (ICP-MS) analyses were used to determine the characteristics of studied sandstones. Field observations in Takriza, Taza North, Tamou open pit mines and Tamari Prospect and factor analysis of geochemical results have been used to determine the geological characteristics and genesis of uranium mineralization in Tarat formation. Field observations revealed that a major accident N30° that can be interpreted as extension of the Austriche accident ensure the controls of Tarat sedimentation and mineralization deposits and the presence oxidized zone and reduced zone indicates the direction of circulation of the mineralized fluids from West to East. The uranium mineralization is disseminated as pitchblende that gives yellow color to the sandstone while, molybdenum mineralization gives blue color to the sandstone. The results of factor analysis of the analyzed sandstone show that there is no direct relationship between organic carbon and uranium indicates the absence of organo-uraniferous composite and uranium mineralization occurs in the association U-Pb-Mo or U-Zn-Ni-Pb. The positive correlation of U-Mo and U-Cu suggest that Tarat uranium mineralization originated from synsedimentary volcanic source while the negative correlation of U-Th and U-Na in our samples indicates intense remobilization of uranium in Tarat formation

Keywords: genesis; factor analysis; tarat formation; uranium mineralization; geochemistry