Mineralogy and geochemistry of the sandstone facies of Campanian Lokoja formation in the Southern Bida basin, Nigeria: implications for provenance and weathering history

Abstract

The upper Cretaceous Lokoja Formation is the earliest deposited stratigraphic unit in the intracratonic Bida Basin, Nigeria. It consists predominantly of sandstone and offers a potential hydrocarbon reservoir in the basin. In this study, we investigated the bulk elemental (major, trace and rare earth elements) and mineralogical compositions of the sandstones for the determination of their compositional maturity, tectonic setting, source and weathering history. The sandstone geochemical data indicates that the samples contain moderate amount of SiO 2 and Al 2 O 3 with average values of 78.3 % and 9.75 % respectively. Relatively high average values of K 2 O (1.59 %) and Na 2 O (1.52 %) and low Fe 2 O 3 (2.56 %), MnO (0.05 %), TiO 2 (0.31 %) and P 2 O 5 (0.018 %) were obtained. Plots of relevant geochemical elements reveal that the sandstones are predominantly arkose and litharenite types with minor sub-litharenites. Application of some trace element geochemical proxies; La/Co (11.78), Th/Co (1.32), La/ Th (7.04) and Eu/Eu* (0.82) to constrain the source history suggest protolith dominated by felsic rock. Relatively low average values of ΣREEs (12.81) and ΣHREEs (1.52) support the felsic provenance of the sandstones and the tectonic setting discriminant function plots indicate passive margin depositional basin. Paleo-weathering plot reveals a moderate humid climatic condition and the mean values of CIA (79.21), CIW (90.51), PIA (66.55) and A-CN-K diagram indicates low to moderate chemical weathering in the source area and compositional immaturity for the sediments. This study concludes that the sandstones of the Lokoja Formation are immature and were derived from the faulted blocks of granitic basement rocks at the margin of the basin and deposited proximally.

Geochemical Characterization of Sedimentary Materials (Limestone, Gypsum, Coal, and Iron Ore) along the Nile River Basin, South Wollo, Ethiopia

“…Analysis. In addition to complete oxide analysis, petrographic analysis was used for the analysis of gypsum [30], sandstone [31], and clay [30] samples.…”

Source Area Weathering and Tectonic History Inferred from the Geochemistry of the Maastrichtian Sandstone from Patti Formation, Southern Bida Basin, North Central Nigeria

“…In addition, although not limited to Falconer [9] , Jones [7] , Adeleye [10] , Jan du Chene et al [11] , Agyingi [12] , Braide [4] , Ladipo et al [13] , Abimbola [14] , Obaje et al [6] ; Udensi and Osasuwa [2] ; Akande et al [15] ; Ojo and Akande [8] ; Nton and Adamolekun [16] ; Odundun and Ogundoro [3] ; Ojo et al [17] focused on the geology, stratigraphy, sedimentology, mineralogy and hydrocarbon potential of the different formations within the basin with paucity of information on the geochemistry of the basin most especially the Patti Formation, Southern Bida Basin to deduce its source area weathering and tectonic setting.…”

“…Geochemical records and parameters associated with siliciclastic sediments are common potential tools to establish the tectonic setting of known sedimentary basins [65,66,39,17] . McLennan et al [65] and Ojo et al [17] , documented that chemical compositions, sandstones can be categorized into different tectonic settings; magmatic island arcs (average SiO 2 : <58%, K 2 O/Na 2 O < 1), Andean-type continental margins (SiO 2 : 68% to 74%, K 2 O/ Na 2 O < 1), Atlantic-type continental margins (average SiO 2 : <89%, K 2 O/Na 2 O > 1).…”

“…Geochemical records and parameters associated with siliciclastic sediments are common potential tools to establish the tectonic setting of known sedimentary basins [65,66,39,17] . McLennan et al [65] and Ojo et al [17] , documented that chemical compositions, sandstones can be categorized into different tectonic settings; magmatic island arcs (average SiO 2 : <58%, K 2 O/Na 2 O < 1), Andean-type continental margins (SiO 2 : 68% to 74%, K 2 O/ Na 2 O < 1), Atlantic-type continental margins (average SiO 2 : <89%, K 2 O/Na 2 O > 1). Applying this parameter, the investigated Patti sandstone which ranged in SiO 2 from 74.01 wt% to 86.24 wt% (Table 3) and K 2 O/Na 2 O from 5 to 9 (Table 6), suggest an Atlantic-type continental margins that compares favourably in term of compositional characteristics with continental platform sands.…”

Geochemical elements as provenance and paleoenvironmental indicators in siliciclastic sediments of Neogene Gwandu formation exposed in Birnin Kebbi Area, Northwestern Nigeria

“…Elsewhere in Nigeria, several researches have been undertaken on geochemistry of Cretaceous, Tertiary and Quaternary sediments with emphasis on various provenance indicator elements (Amajor, 1987;Ehinola and Abimbola, 2002;Madukwe and Bassey, 2015;Phillips et al, 2017a;2017b;Madukwe, 2019;Amiewalan et al, 2020;Overare et al, 2020;Ojo et al, 2021).…”