A multi-proxy study, including mineralogy, whole rock geochemistry and palynology analyses, was conducted on 79 samples (64 bulk sediment and 10 pyrite samples) from two sites (ES and DA) located in the Tondè area, Douala sub-basin (Cameroon) to unravel the paleoenvironmental and paleoclimatic conditions prevailing in recent continental deposits. Lithologies of this locality mainly consist of pyriteous claystones (grey and red) and unconsolided sandstones. Encountered pyrite is euhedral (isolated and clusters crystals) and massive with diverse morphologies and sizes. In both sections, major and trace elements show that the clayey materials result from weathering of an intermediate source rock, probably from the surrounding basement (gneiss and micaschist), whereas the sandy materials appear to be recycled. Palynological data consists of a few index species such as Malvaceae and graminaceae which indicate Pleistocene-Holocene age deposits of continental origin (swampy bays of seaside and hinterland). This area was subjected to intense chemical alteration (high CIA values: 97.35–99.43%) as testified by the mineralogical phases, mainly consist of kaolinite, quartz and goethite. Mean annual precipitation (MAP = 221.1e^{0.0197(CIA-K)}; ±181 mm.y⁻¹) and mean annual temperature (MAT = 46.9C + 4; ±0.6 °C) are 1575 ±181 mm.y⁻¹ and 25.2 ± 0.6 °C for ES site and then 1566 ± 181 mm.y⁻¹ and 20.3 ± 0.6 °C for DA, thus reflecting a subequatorial to equatorial climate. The pyrite geochemistry is characterized by a weak Al vs. ΣREE positive correlation (r² = 0.02), a positive Eu anomaly relative to PAAS and a significant negative correlation between ΣREE and the Eu anomaly (r² = −0.83). These results indicate that pyrite is a late diagenesis product formed by a secondary enrichment and coupled with precipitation under more reducing conditions, linked to the water table fluctuation.

在位于杜阿拉次流域（喀麦隆）通德地区的两个地点（ES和DA）对79个样品（64个堆积沉积物和10个黄铁矿样品）进行了包括矿物学，整个岩石地球化学和孢粉学分析在内的多代理研究。 ）揭示近期大陆沉积物中普遍存在的古环境和古气候条件。该地区的岩性主要由黄铁质粘土岩（灰色和红色）和未固结砂岩组成。遇到的黄铁矿是软质的（分离的晶体和簇状晶体），块状，形态和大小各异。在这两个部分中，主要元素和微量元素均表明，黏土材料是由中间烃源岩的风化产生的，可能来自周围的地下室（片麻岩和云母片岩），而砂质物质似乎是可循环利用的。孢粉学数据由几个指数物种组成，例如锦葵科和禾本科，表明大陆起源的更新世-全新世时代沉积物（海边和腹地的沼泽海湾）。该区域经历了强烈的化学变化（高CIA值：97.35–99.43％），矿物相证实，主要由高岭石，石英和针铁矿组成。年平均降水量（MAP = 221.1e^{0.0197（CIA-K）} ; ±181 mm.y ^-1）和年平均温度（MAT = 46.9C + 4;±0.6°C）为ES站点为1575±181 mm.y ^-1和25.2±0.6°C，然后为1566±181 mm。 y ^-1和DA的20.3±0.6°C，因此反映了赤道以下至赤道的气候。黄铁矿的地球化学特征是Al与ΣREE呈弱正相关（r ² = 0.02），相对于PAAS具有正Eu异常，而ΣREE与Eu异常之间呈显着负相关（r ² = -0.83）。这些结果表明，黄铁矿是一次成岩作用的后期产物，是次生富集作用的产物，再加上在更多还原条件下的降水，与地下水位波动有关。