Abstract The petrographic and geochemical compositions of the Campanian-Maastrichtian siliciclastic sediments in the northern Bida Basin, North-central Nigeria were investigated with the aim to determine the petrofacies, their provenance and tectonic settings. The mineral composition of the samples selected from the 10 sub-facies in the study area is characterized by abundant quartz (predominantly of monocrystalline quartz) and minor feldspar, rock fragments and heavy minerals. The framework grains are angular, sub-angular to sub-rounded and well sorted with the quartz varieties exhibiting euhedral to subhedral, non-undulose to undulose characteristics. The modal composition reveals the sediments as quartzarenite to sublitharenite with minor sub-arkoses and also reflects felsic rocks derived within passive margin paleotectonics as provenance. Geochemical proxies obtained based on major, trace and rare earth elements data; Al2O3/TiO2, SiO2/Al2O3, K2O/Al2O3, La/Th, La/Co, Th/Co, La/Sc, Cr/Th, Zr/Nb and Zr/Th with chondrite-normalized REE patterns, light REE enrichment, heavy REE flat pattern and negative Eu anomalies revealed sediments derivation mainly from felsic source rocks. A higher Zr/Sc and Zr/Hf ratio with Th/Sc and Zr/Sc binary plot suggest considerable zircon enrichment in the source areas. Discrimination plots; log(K2O/Na2O) versus SiO2, TiO2 versus (Fe2O3+MgO), Al2O3/SiO2 versus (Fe2O3+MgO) and SiO2/20-(K2O+Na2O)-(TiO2+Fe2O3+MgO), La/Y versus Sc/Cr, La-Th-Sc, Th-Sc-Zr/10 of the analyzed sandstones suggest that source rocks may lie in the passive continental margin, before sediment transport and deposition in the basin by fluvial modes. This study suggests a passive paleotectonic setting for the Precambrian Basement Complex consisting of two igneous source materials from which the sediments are derived and supplied to the study area.

中文翻译：

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尼日利亚中北部比达盆地北部上白垩统砂岩岩相、物源和构造环境的岩石学和地球化学约束

摘要 研究了尼日利亚中北部比达盆地北部坎帕阶-马斯特里赫特硅质碎屑沉积物的岩石学和地球化学成分，以确定岩相、来源和构造环境。从研究区10个亚相中选取的样品，其矿物组成以丰富的石英（以单晶石英为主）和少量长石、岩屑和重矿物为特征。骨架颗粒有棱有角，从亚角到亚圆，分选良好，石英品种表现出自形到亚自形，非波状到波状特征。模态成分显示沉积物为石英砂岩至亚长石岩，并含有少量亚长石岩，也反映了被动边缘古构造中衍生的长英质岩作为物源。基于主要、微量和稀土元素数据获得的地球化学指标；Al2O3/TiO2、SiO2/Al2O3、K2O/Al2O3、La/Th、La/Co、Th/Co、La/Sc、Cr/Th、Zr/Nb 和 Zr/Th 具有球粒陨石归一化 REE 模式，轻稀土富集，重稀土平坦模式和负 Eu 异常表明沉积物主要来自长英质烃源岩。较高的 Zr/Sc 和 Zr/Hf 比值以及 Th/Sc 和 Zr/Sc 二元图表明源区的锆石富集相当多。判别图；log(K2O/Na2O) 与 SiO2、TiO2 与 (Fe2O3+MgO)、Al2O3/SiO2 与 (Fe2O3+MgO) 和 SiO2/20-(K2O+Na2O)-(TiO2+Fe2O3+MgO)、La/Y 与 Sc /Cr、La-Th-Sc、Th-Sc-Zr/10 分析的砂岩表明烃源岩可能位于被动大陆边缘，在沉积物通过河流模式在盆地中输送和沉积之前。