Comprehensive field, litho-, biostratigraphy, and paleoenvironmental studies of the upper Paleocene–lower Eocene (P–E) boundary interval in the Gabal El-Gir area were conducted. Two selected sections El-Gir-1 and El-Gir-2 were investigated. The prevailed paleoenvironmental conditions were discussed in the frame of the nannofossils, planktonic, and benthic foraminiferal assemblages. Benthic foraminifera assemblages indicate a remarkable turnover across the PETM. The extinction of Angulogavelinella avnimelechi at the base of the PETM represents a significant marker for the base of the benthic foraminifera extinction event at this site and other neritic sites in the Tethyan region. The dominance of calcareous planktonic excursion taxa at the base of the PETM indicates adaptation to extremely warm sea surface temperatures and low nutrient levels. Also, our data suggests that the biotic responses to environmental change in the early Eocene resembled those observed in the early Eocene hyperthermals at the nearbay Dababiya and El-Ballas sections. This could indicate that similar processes characterized the Egyptian sedimentary basin during the early Eocene. Stratigraphically, despite the limited distance between the studied sections, the Dababiya Quarry Member (DQM) in El-Gir-1 resemble those of the Global Stratotype Section and Point (GSSP) but reduced in thickness. While in El-Gir-2, the lower part of the DQM was missing. These findings could indicate that the DQM was deposited in a submarine channel. Three third-order depositional sequences were recognized covering the P–E interval. The reconstructed sea level curve shows the presence of eustatic similarities with the global sea level.

对 Gabal El-Gir 地区上古新世-下始新世 (P-E) 边界区间进行了综合野外、岩石、生物地层学和古环境研究。对两个选定的部分 El-Gir-1 和 El-Gir-2 进行了研究。在超微化石、浮游生物和底栖有孔虫组合的框架内讨论了当时的古环境条件。底栖有孔虫类群表明古新世新世时期的显着更替。PETM 底部的Angulogavelinella avnimelechi灭绝是该地点和特提斯地区其他浅海地点底栖有孔虫灭绝事件的重要标志。PETM 底部的钙质浮游类群占主导地位，表明它们对极其温暖的海面温度和低营养水平的适应。此外，我们的数据表明，始新世早期生物对环境变化的反应与在达巴比亚和埃尔巴拉斯海湾附近的始新世早期高温中观察到的反应相似。这可能表明始新世早期埃及沉积盆地也存在类似的过程。在地层学上，尽管研究剖面之间的距离有限，但 El-Gir-1 的 Dababiya 采石场段 (DQM) 与全球层型剖面和点 (GSSP) 相似，但厚度减小。在 El-Gir-2 中，DQM 的下部缺失。这些发现可能表明 DQM 沉积在海底通道中。在 P-E 区间内发现了三个三级沉积层序。重建的海平面曲线显示与全球海平面存在海平面上升的相似性。