The Cretaceous - Tertiary Clastic Rocks Weathering

A total number of 210 ditch cuttings samples of carbonaceous shale, sandstones and mudstones of Maastrichtian? Paleocene sequence from Mushe , Sa, Tuma and Ziye wells from Bornu Basin were considered for this study. The intention was to understand the paleo-weathering history of the sediment detail lithological and bulk geochemical analyses using Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The data from these analyses were evaluated using four common silicate weathering indices; Alteration (CIA), Plagioclase Index of Alteration (PIA), Chemical Index of Weathering (CIW) and Ruxton Ratio (RR). Theseallowedfor a proper interpretation of weathering trends in reconnaissance samples from the study area. The lithologic study showed a basin dominated by argillaceous and arenaceous sediments deposited in fluvio to lagoonal settings. The results from weathering indices for Mushe, Sa, Tuma and Ziyeare CIA =79.4, 75.5, 88.7 and 82.4%;CIW=82.1, 78.2, 92.2 and 84.8%;PIA respectively. The above results suggest that the weathering indices ( using CIW, CIA, PIA and RR) revealed sediments subjected