近日，尼日利亚贝宁大学Aitalokhai J. Edegbai团队报道了尼日利亚南部部分地区微量元素硒浓度的基线数据显示了物源和古沉积控制。相关论文于2026年3月3日发表在《地球化学学报》杂志上。

研究组评估了尼日利亚南部部分地区上白垩统和古近系泥岩中的硒含量，并探讨了控制硒含量的地质因素。研究对来自贝努埃槽南部Anambra盆地和Niger三角洲盆地的73个泥岩露头样品（包括河口相晚坎帕期-中马斯特里赫特期Mamu组）以及穿透海相古近系Imo组的水井岩屑样品进行了地球化学分析（主量元素、微量元素、总有机碳和总无机碳）及pH值测定。结果显示，古近系钙质海相泥岩样品的硒含量最高可达21 ppm，显著高于上白垩统河口相泥岩样品。

协变图表明，河口相泥岩样品中硒的吸附作用主要发生在黏土矿物和含铁矿物上，有机质吸附有限；而钙质海相泥岩中硒的吸附作用主要发生在黏土矿物和方解石上，含铁矿物的固定作用非常有限。主成分分析和冗余分析表明，碳酸盐矿物对硒的固定起主导作用。此外，古近系钙质海相泥岩样品的酸性较弱（平均pH 5.92），而上白垩统河口相泥岩样品的平均pH为5.02。因此，推测较高的pH值可能略微提高硒的生物有效性，导致在古近系钙质泥岩分布区的植物对硒的吸收量较高。

附：英文原文

Title: Baseline data on selenium micronutrient concentration in parts of Southern Nigeria show provenance and paleodepositional controls

Author: Edegbai, Aitalokhai J., Owonaro, Jennifer B., Pajiah, Jubemi A., Omietimi, Erepamo J., Lenhardt, Nils, Ukpebor, Justina E.

Issue&Volume: 2026-03-03

Abstract: This study evaluates the Se concentration and examines the geologic controls on Se concentration in Upper Cretaceous and Palaeogene mudrocks in parts of Southern Nigeria. Geochemical analysis [(major and trace elements, total organic and inorganic carbon (TOC and TIC)] and pH measurements were conducted on seventy-three mudrock outcrop samples from the estuarine Late Campanian to Mid-Maastrichtian Mamu Formation and ditch cuttings from water wells that penetrated the marine Palaeogene Imo Formation from the Anambra basin and Niger Delta basin in the Southern Benue Trough. Selenium concentration in the Palaeogene calcareous marine mudrock samples reaches up to 21 ppm, significantly exceeding data observed in the Upper Cretaceous estuarine mudrock samples. Covariation charts suggest that Se adsorption onto clay, Fe-minerals, and limited sorption by organic matter in the estuarine mudrock samples are compared to adsorption onto clays, calcite, and very limited sequestration by Fe-minerals observed in the calcareous marine mudrocks. Principal component analysis and redundancy analysis reveal a dominant influence of carbonate minerals on selenium sequestration. Additionally, the Palaeogene calcareous marine mudrock samples are less acidic (mean pH 5.92) than the Upper Cretaceous estuarine mudrocks with a mean pH of 5.02. Therefore, it is hypothesized that higher pH may slightly promote the bioavailability of Se, resulting in higher Se intake by plants in areas underlain by the Palaeogene calcareous mudrocks.

DOI: 10.1007/s11631-026-00856-4

Source: https://link.springer.com/article/10.1007/s11631-026-00856-4