The distribution of trace metals in active stream sediments from the mineralized Lom Basin has been evaluated. Fifty-five bottom sediments were collected and the mineralogical composition of six pulverized samples determined by XRD. The fine fraction (< 150 µm) was subjected to total digestion (HClO4 + HF + HCl) and analyzed for trace metals using a combination of ICP-MS and AAS analytical methods. Results show that the mineralogy of stream sediments is dominated by quartz (39-86%), phyllosilicates (0-45%) and feldspars (0-27%). Mean concentrations of the analyzed metals are low (e.g. As = 99.40 µg/kg, Zn = 573.24 µg/kg, V = 963.14 µg/kg and Cr = 763.93 µg/kg). Iron and Mn have significant average concentrations of 28.325 and 442 mg/kg, respectively. Background and threshold values of the trace metals were computed statistically to determine geochemical anomalies of geologic or anthropogenic origin, particularly mining activity. Factor analysis, applied on normalized data, identified three associations: Ni-Cr-V-Co-As-Se-pH, Cu-Zn-Hg-Pb-Cd-Sc and Fe-Mn. The first association is controlled by source geology and the neutral pH, the second by sulphide mineralization and the last by chemical weathering of ferromagnesian minerals. Spatial analysis reveals similar distribution trends for Co-Cr-V-Ni and Cu-Zn-Pb-Sc reflecting the lithology and sulphide mineralization in the basin. Relatively high levels of As were concordant with reported gold occurrences in the area while Fe and Mn distribution are consistent with their source from the Fe-bearing metamorphic rocks. These findings provide baseline geochemical values for common and parallel geological domains in the eastern region of Cameroon. Although this study shows that the stream sediments are not polluted, the evaluation of metal composition in environmental samples from abandoned and active mine sites for comparison and environmental health risk assessment is highly recommended.

中文翻译：

---

喀麦隆东部洛美盆地矿化区内潜在有毒微量金属的区域地球化学基线浓度：一种污染评估工具。

对矿化的Lom盆地活跃流沉积物中痕量金属的分布进行了评估。收集了55个底部沉积物，并通过XRD确定了6个粉碎样品的矿物学组成。将细颗粒（<150 µm）进行总消解（HClO4 + HF + HCl），并结合使用ICP-MS和AAS分析方法分析痕量金属。结果表明，河流沉积物的矿物学以石英（39-86％），页硅酸盐（0-45％）和长石（0-27％）为主。分析金属的平均浓度较低（例如，As = 99.40 µg / kg，Zn = 573.24 µg / kg，V = 963.14 µg / kg，Cr = 763.93 µg / kg）。铁和锰的平均浓度分别为28.325和442 mg / kg。统计计算痕量金属的背景和阈值，以确定地质或人为起源的地球化学异常，特别是采矿活动。应用归一化数据的因子分析确定了三个关联：Ni-Cr-V-Co-As-Se-pH，Cu-Zn-Hg-Pb-Cd-Sc和Fe-Mn。第一个关联受源地质和中性pH值控制，第二个关联受硫化物矿化作用，最后一个受铁磁矿物的化学风化作用控制。空间分析揭示了Co-Cr-V-Ni和Cu-Zn-Pb-Sc的相似分布趋势，反映了盆地中的岩性和硫化物矿化。相对较高的砷含量与该地区报道的金矿床一致，而铁和锰的分布与其来自含铁变质岩的来源一致。这些发现提供了喀麦隆东部地区常见和平行地质区域的基线地球化学值。尽管这项研究表明溪流沉积物未受到污染，但强烈建议对废弃矿山和活动矿山环境样品中的金属成分进行评估，以进行比较和环境健康风险评估。