The geology of Gulani area is composed of Precambrian basement complex of the Older Granite suit (diorite and granites), the Cretaceous sediments of Bima, Yolde and Pindiga Formations and the Tertiary/Quaternary basalts of the Biu Plateau. Epigenetic barite-copper mineralization with barite associated with sandstones and copper occurring in granites have been mapped in the area. Unaltered (distal), hydrothermally altered (proximal) host rocks and barite and chalcopyrite/malachite mineral separates were sampled and investigated petrographically and geochemically for their trace element abundances. Reflected light microscopy of the Cu-mineralized granites show that chalcopyrite constitutes the primary sulphide veins/veinlets materials which altered to malachite and its associated limonite through the processes of hydrolysis and oxidation. Trace element geochemistry reveals that barite mineralization areas are characterized by remarkable enrichment of Ba and Sr and depletion of Rb from the distal sandstones through the proximal sandstones to the barite vein materials where the Ba content is >500,000 ppm (>50%). In the copper mineralization areas, Cu is enriched to values >10,000 ppm (>1%) in the copper mineralized granites and chalcopyrite/malachite separate. However, the Cu mineralization is accompanied by depletion of Ba, Sr and Rb and enrichments of Ag, U, V, Zr, Pb and Y.There are therefore, remarkable contrasts in respect of the trace elements behavior and abundances between barite and copper mineralization areas probably due to the variations in fluids origin, fluids and host rock compositions (sandstones and granites), the chemical activities (intensities) and temperatures of the hydrothermal fluids responsible for the deposition of barite and copper deposits.