The distribution of gold in the weathering blanket at the Belikombone gold prospect in east Cameroon provides insights into gold mobility in the secondary environment and in tropical terrains worldwide. Both gridline-controlled sampling of topsoil (surface samples) and sampling of various layers in pits are used and the gold assay for each sample determined by NiS fire assay with ICP-AES finish. One hundred and thirty-two (132) surface samples and a total of 206 samples from 19 exploration pits were analyzed. The results from the topsoil samples show an anomaly with the highest Au concentration at 5.9 mgkg⁻¹. The mineralization corridor follows a NE-SW trend. The horizons within the pits range from sap rock at the base, through saprolite, rubble layer rich in relict quartz material to a ferruginous loose layer at the top although some horizons are missing in some pits. All the layers contain gold and the highest concentration in the sap rock horizon is 3.4 mgkg⁻¹ while the rubble layer has a gold high of 6.1 mgkg⁻¹. The individual soil horizons show no systematic gold trends and given the presence of gold in all layers, the patterns point towards supergene dissolution and redistribution of gold. Gold enrichment within the upper horizons in the weathering blanket is attributed to sequestration by Fe oxides of chemically remobilized gold. However, the high gold content within the sap rock and saprolite layers suggests that migration of gold in the particulate form supersedes chemical gold redistribution. Particulate gold obtained by panning samples from the pits varies in shape from euhedral, elongated to irregular. Electron microprobe analysis on the grains record high contents of gold in the rim zones (90.0 to 99.8 wt%). The cores are relatively rich in Ag (12.6 to 14.2 wt%) while the rims are poor in Ag. The low Ag content in the rims is attributed to the preferential leaching of Ag. The soil pH value in this area varies between 3.6 and 7.3. Under such acidic to near neutral conditions, bisulfide and thiosulfate ions can dissolve and transport Au and Ag to be precipitated under surficial conditions creating authigenic Au haloes especially in the saprolite and sap rock layers. Such pH values together with oxidizing Eh conditions explain the solubility of gold in the area. These results are important for geochemical exploration of gold in tropical terrains, and confirm previous studies.

喀麦隆东部 Belikombone 金矿勘探区风化层中金的分布提供了对次生环境和全球热带地形中金流动性的深入了解。使用网格线控制的表土（表面样品）采样和坑中不同层的采样，每个样品的金含量由 NiS 火焰分析和 ICP-AES 完成。分析了一百三十二 (132) 个地表样品和来自 19 个勘探坑的总共 206 个样品。表土样品的结果显示异常，Au 浓度最高为 5.9 mgkg ^-1. 矿化走廊遵循 NE-SW 趋势。矿坑内的地层范围从底部的树液岩到腐泥土、富含残留石英材料的碎石层，再到顶部的铁质松散层，尽管在某些矿坑中缺少一些地层。所有层都含有金，在树液岩层中的最高浓度为 3.4 mgkg ^-1而碎石层的金浓度最高为 6.1 mgkg ^-1. 各个土壤层没有显示出系统的金趋势，并且鉴于所有层中都存在金，这些模式指向金的表生溶解和重新分布。风化层上层金的富集归因于化学再迁移金的 Fe 氧化物的螯合。然而，树液岩和腐泥土层中的高金含量表明，颗粒形式的金迁移取代了化学金的再分布。通过从坑中淘选样品获得的颗粒金形状从自形、拉长到不规则不等。对晶粒的电子微探针分析记录了边缘区域中金的高含量（90.0 至 99.8 重量％）。核心的 Ag 含量相对丰富（12.6 至 14.2 wt%），而轮辋的 Ag 含量较低。边缘中的低 Ag 含量归因于 Ag 的优先浸出。该地区土壤 pH 值在 3.6 和 7.3 之间变化。在这种酸性到接近中性的条件下，二硫化物和硫代硫酸根离子可以溶解和运输 Au 和 Ag，使其在地表条件下沉淀，产生自生 Au 晕，尤其是在腐泥土和树液岩层中。这样的 pH 值与氧化 Eh 条件一起解释了金在该区域的溶解度。这些结果对于热带地区金的地球化学勘探很重要，并证实了以前的研究。二硫化物和硫代硫酸根离子可以溶解和运输 Au 和 Ag 在地表条件下沉淀，产生自生 Au 晕，尤其是在腐泥土和树液岩层中。这样的 pH 值与氧化 Eh 条件一起解释了金在该区域的溶解度。这些结果对于热带地区金的地球化学勘探很重要，并证实了以前的研究。二硫化物和硫代硫酸根离子可以溶解和运输 Au 和 Ag 在地表条件下沉淀，产生自生 Au 晕，尤其是在腐泥土和树液岩层中。这样的 pH 值与氧化 Eh 条件一起解释了金在该区域的溶解度。这些结果对于热带地区金的地球化学勘探很重要，并证实了以前的研究。