SANDSTONE COMPOSITION AND PROVENANCE ANALYSIS OF PART OF BIDA FORMATION, NOTHERN BIDA BASIN, NIGERIA

Abstract

Provenance studies is important for the sandstones of Bida basin in order to accurately decipher paleogeography and for assessment of the sandstone’s aquifer and reservoir properties. Geochemical methods were used by earlier researchers but thin section petrography was not used for provenance studies in the basin. This project integrates outcrop studies and thin section mineralogical composition to determine the source lithology, plate tectonic setting and paleoclimatic conditions of part of Bida Formation exposed around Doko-Jima Junction in Northern Bida basin, Nigeria. Thin section mineralogy reveals quartz content to be averagely 63% while the feldspar content is less than 1% and the lithic fragment is 37% which classifies the sandstones as litharenites. Matrix was generally absent in the sandstones and the identified cements were mainly iron oxide. The sandstones display angular to subangular shapes which suggest short transportation of the sediments before deposition in fluvial environments. Plots of modal compositions of the sandstones on triangular QFL discrimination diagrams suggest that the paleo-plate tectonic setting was recycled orogens, while the source lithology was metamorphic and the climate was humid. These interpretations were supported by the lack of feldspar, abundant quartz and abundant lithic fragments composed of sedimentary and metasedimentary rock fragments such as chert and quartzite. This project has shown that the integration of field and thin section analyses is vital to sandstone provenance studies.