埃及爱资哈尔大学Amin, Alaa T. A团队等，报道了埃及Beni Suef东部地区一些古近系沉积的地质研究及热处理。2024年7月24日出版的《地球化学学报》杂志发表了这一最新研究成果。

据悉，本文对埃及Beni Suef地区东部古近纪沉积的地质背景、相特征和地球化学特征，包括热重分析进行了详细研究。

岩石地层学上，该地区由三个岩石单元组成，从最老到最新依次为:Beni Suef组(中晚始新世)Tarbul段、Maadi组(晚始新世)和Gebel Ahmar组(渐新世)，该组在Beni Suef地区(埃及)东部首次出现。研究通过对在低—高能和浅海潮下条件下的样品薄片进行显微镜下鉴定，确定了7种微相类型(F1-F7)。岩石地层、岩石学和地球化学结果表明，本区始新世地层主要由碳酸盐和硅屑组成。

渐新世Gebel Ahmar组主要由二氧化硅和氧化铁组成。研究区岩石单元氧化铁富集，特别是Gebel Ahmar组中微量元素Zr、Ba、V、Sr含量较高，反映了渐新世期间热液的影响。TGA以恒定速率监测加热过程中的重量变化，以确定材料的热稳定性和挥发性成分含量。Gebel Ahmar组的含铁砂岩在受到热影响时表现出不同的分解阶段，TGA显示从61.8°C开始初始质量下降。而Maadi组含氧化铁灰岩在650-875℃之间表现为单相质量下降。

附：英文原文

Title: Geological studies and thermal treatment of some Paleogene deposits in east Beni Suef region, Egypt

Author: Amin, Alaa T. A., El-Mezayen, Ahmed M., Elkholy, Darweesh M., Khamis, Hossam A., Sarhan, Hazem K. A.

Issue&Volume: 2024-07-24

Abstract: Geological setting, facies characteristics, and geochemistry, including TGA (thermo-gravimetric analysis) of Paleogene deposits in east Beni Suef region (Egypt), were studied in the present work. Lithostratigraphically, the area consists of three rock units, arranged from oldest to youngest: Tarbul Member of Beni Suef Formation (Middle-Late Eocene), Maadi Formation (Late Eocene), and Gebel Ahmar Formation (Oligocene), this last formation registered for the first time in the east of Beni Suef area (Egypt). Seven microfacies types (F1–F7) were determined by the microscopic examination of the studied samples in low- to high-energy and shallow-subtidal marine conditions. The lithostratigraphic, petrological, and geochemical results revealed that the Eocene succession in the present area is composed mainly of carbonates as well as siliciclastics. The Oligocene Gebel Ahmar Formation consists mainly of silica and iron oxides. The enrichment of the rock units with iron oxides in the studied area, as well as the high proportions of trace elements such as Zr, Ba, V, and Sr, in particular in the Gebel Ahmar Formation, reflects the influence of the hydrothermal solutions during the Oligocene. TGA, which monitors weight changes during heating at a constant rate, was used to determine the thermal stability and volatile component content of the materials. The ferruginous sandstone of Gebel Ahmar Formation exhibits various decomposition phases when exposed to thermal influences, with TGA indicating an initial mass decrease starting at 61.8 °C. In contrast, the ferruginous limestone of the Maadi Formation shows a single-phase mass decrease between 650 and 875 °C.

DOI: 10.1007/s11631-024-00720-3

Source: https://link.springer.com/article/10.1007/s11631-024-00720-3