Combined whole-rock geochemistry, zircon U–Pb dating, and Sr–Nd–Pb isotopic analyses were carried out to constrain the petrogenesis and tectonic implications of the “Zaranda Older Granites” (ZOG) and “Younger Granites” (ZYG) in north-central Nigeria. Zircon U–Pb dating yielded 633 ± 3 Ma for the ZOG and 203 ± 1 Ma for the ZYG, corresponding to Late Neoproterozoic and Late Triassic, respectively. The ZOG consists dominantly of biotite granite, which displays a whole-rock ɛNd(t) values of − 3.48 to − 5.00 and Nd model ages of 1620–1720 Ma. Most ZOG samples exhibit elevated Sr/Y (107–128) and La/Yb ratios (36–40), with a positive Eu anomaly (Eu/Eu* = 2.2–2.58), interpreted to reflect magma derivation through partial melting of a thickened lower crust. The ZOG is geochemically and geochronologically similar to the Pan-African granites from Togo–Benin (West Africa) and Northeast Borborema, Sao Paulo (Brazil), suggesting that their emplacement probably marked the initial phase of the Pan-African orogeny during which the Gondwana was amalgamated. The ZYG consists of compositionally diverse alkaline granitoids including aegirine syenites, quartz syenite, and fayalite granite porphyry. These rocks are strongly ferroan, alkalic and show petrographic and geochemical features of classical A-type granites. Substantial depletion in Ba, Sr, P, Ti, and Eu signifies fractionation of felsic and mafic minerals such as feldspar, biotite, amphibole, and Ti-rich augite. The low Y/Nb and Yb/Ta ratios (≤ 2) indicate that the ZYG samples display geochemical features typical of OIB-derived A-type granites. The ɛNd(t) values in the ZYG range from + 4.16 to − 2.76 and the Nd model ages range from 0.6 to 1.2 Ga. Based on these results, we propose that the ZYG samples and by extension, other alkaline granitoids from the Nigerian Younger Granite (NYG) province with similar geochemical compositions were likely generated through extensive differentiation of OIB-type mantle-derived magma. The concentrations of Nb and other HFSEs are much higher in ZYG than ZOG, indicating that the former has higher rare metal mineralization potential.

结合整体岩石地球化学，锆石U-Pb测年和Sr-Nd-Pb同位素分析，以约束北部“ Zaranda老花岗岩”（ZOG）和“年轻花岗岩”（ZYG）的岩石成因和构造意义。尼日利亚中部。锆石U–Pb测年的ZOG的结果为633±3 Ma，ZYG的结果为203±1 Ma，分别对应于新元古代晚期和三叠纪晚期。ZOG主要由黑云母花岗岩组成，其整体岩石wholeNd（t）值-3.48至-5.00，Nd模型年龄为1620–1720 Ma。大多数ZOG样品均表现出较高的Sr / Y（107–128）和La / Yb比（36–40），且Eu异常呈正值（Eu / Eu * = 2.2–2.58），这被解释为反映了通过部分熔融而形成的岩浆衍生。下地壳变厚。ZOG在地球化学和时间上与从多哥-贝宁（西非）和东北博博雷马，圣保罗（巴西）的泛非花岗岩相似，这表明它们的位置可能标志着泛非造山运动的初始阶段，在此期间冈瓦纳被合并了。ZYG由组成多样的碱性花岗石组成，包括埃吉里恩正长岩，石英正长岩和铁橄榄石花岗岩斑岩。这些岩石具有强烈的铁质，碱性，并显示出经典A型花岗岩的岩石学和地球化学特征。Ba，Sr，P，Ti和Eu的大量消耗表明，长石，黑云母，闪石，闪石和富含Ti的钠长石等长英质和镁铁质矿物分馏。低的Y / Nb和Yb / Ta比（≤2）表明ZYG样品显示出OIB衍生的A型花岗岩典型的地球化学特征。ɛNd（ZYG的t）值范围为+ 4.16至-2.76，Nd模型的年龄范围为0.6至1.2 Ga。基于这些结果，我们建议使用ZYG样品，并据此扩展尼日利亚年轻花岗岩（NYG ）OIB型地幔衍生岩浆的广泛分化可能产生了具有相似地球化学成分的省。ZYG中Nb和其他HFSE的浓度远高于ZOG，表明前者具有更高的稀有金属矿化潜力。