Geochemical and mineralogical analyses data are presented for ignimbritic deposits from the Bambouto volcano. These deposits are characterized by their welded and non-welded massive lapilli tuff and massive lithic breccias facies. The ignimbrites generally display vitroclastic and/or eutaxitic texture characterized by whole or broken minerals, subangular fragments of trachytes, rhyolites, ignimbrites, as well as fiammes, and fragments of glass. The geochemistry of the ignimbrites of Mount Bambouto indicates that they are alkaline and peralkaline with rhyolitic and trachytic composition. The behaviour of the major and trace elements suggest that ignimbrites, as well as felsic and mafic lavas of the Bambouto volcano have an evolution dominated by fractional crystallization (FC). The La/Yb, Ce/Zr and Th/Nb ratios for Mt Bambouto ignimbrites (19.92–52.66; 0–0.48; 0.10–0.12, respectively) and the whole Western Cameroon Highlands (WCH) and Mt Manengouba lavas (15.58–34.29; 0–0.61; 0–0.27, respectively) also reflect the dominant role of FC. This suggests a relatively constant degree of partial melting during the petrogenesis of the lavas and deposits. The high Rb/Sr (0.52–28.98) and the low ratios of LILE/HFSE (Rb/Nb: 0.08–0.95; Rb/Zr: 0.01–0.18; Th/Ta: 1.38–2.1; Ba/Nb: 0.06–8.27) in Mt. Bambouto ignimbrites, compared with the very high value of these ratios in the granitic basement rocks of the area, preclude the petrogenesis of the ignimbrites from the melting of the Pan-African basement. The weak values of Th/La and La/Nb in the studied ignimbrites and other WCH lavas suggest that crustal contamination was insignificant during ascent and storage of the magma in shallow magma chambers prior to their release to the surface. The similarities in Nb/Ta, Zr/Hf and Nb/U ratios in the Mt Bambouto ignimbrites (Nb/Ta: 13.54–20.93; Zr/Hf: 37.39–49.95; Nb/U: 26.04–55.70) and the lavas of the WCH (Nb/Ta: 11.3–19.57; Zr/Hf: 33.16–55.01; Nb/U: 19.83–75.35) corroborated with their similar source origin. The enrichment of light REE relative to heavy REE or their Dy/Yb > 2 (2.03–2.97), (La/Yb)_N > 5 (14.29–46.69) and (Tb/Yb)_N > 1.9 (1.91–2.9) suggest melting in a garnet-bearing mantle.

给出了班班图火山的火成岩沉积物的地球化学和矿物学分析数据。这些沉积物的特征是它们的焊接和非焊接大块青海凝灰岩和块状角砾岩相。着火物通常显示出玻璃质碎屑和/或共晶质地，其特征是全部或破碎的矿物，菱形的长角形碎片，流纹岩，着火物，以及火焰状碎片和玻璃碎片。班博图山的火成岩的地球化学表明它们是碱性的和碱性的，具有流纹和疏松的成分。主要元素和微量元素的行为表明，班布图火山的火成岩以及长英质和镁铁质熔岩的演化主要由分步结晶（FC）决定。班布图山火成岩的La / Yb，Ce / Zr和Th / Nb比（19.92–52。66; 0–0.48；分别为0.10-0.12）和整个喀麦隆西部高地（WCH）和曼嫩哥巴山熔岩（分别为15.58-34.29； 0-0.61； 0-0.27）也反映了FC的主导作用。这表明在熔岩和沉积物的成岩过程中部分熔融的程度相对恒定。高Rb / Sr（0.52-28.98）和低LILE / HFSE比（Rb / Nb：0.08-0.95; Rb / Zr：0.01-0.18; Th / Ta：1.38-2.1; Ba / Nb：0.06-8.27 ）。与该地区花岗岩基岩中这些比率的极高值相比，Bambouto火成岩阻止了泛非洲基底融化导致火成岩的成岩作用。在研究的火成岩和其他WCH熔岩中，Th / La和La / Nb的值很弱，表明在将岩浆释放到地面之前，在浅岩浆室内上升和储存岩浆的过程中，地壳污染微不足道。班布图山火山岩中Nb / Ta，Zr / Hf和Nb / U比的相似性（Nb / Ta：13.54–20.93； Zr / Hf：37.39–49.95； Nb / U：26.04–55.70）和熔岩WCH（Nb / Ta：11.3–19.57； Zr / Hf：33.16–55.01； Nb / U：19.83–75.35）证实了其来源相似。轻质稀土元素相对于重质稀土元素的富集或其Dy / Yb> 2（2.03-2.97），（La / Yb）35）证实了它们的相似来源。轻质稀土元素相对于重质稀土元素的富集或其Dy / Yb> 2（2.03-2.97），（La / Yb）35）证实了它们的相似来源。轻质稀土元素相对于重质稀土元素的富集或其Dy / Yb> 2（2.03-2.97），（La / Yb）_N > 5（14.29–46.69）和（Tb / Yb）_N > 1.9（1.91–2.9）表明在石榴石地幔中融化。