Structural setting, facies characteristics, and geochemical aspects of the Middle-Upper Eocene outcrops along Beni Suef-El Zaafarana New Road, east of Beni Suef, Egypt

Abstract

he Eocene epoch is distinguished by the development of a carbonate platform covering a large area of Egypt. These Eocene carbonates are widespread in the eastern Beni Suef region of Egypt. In the present work, the lithostratigraphy, structural setting, petrography, geochemistry, and petrology of the Middle-Upper Eocene deposits east of Beni Suef, along both sides of the Beni Suef-El Zaafarana New Road, were studied. Stratigraphically, the present area exhibits two rock units arranged from base to top: the Beni Suef Formation and the Maadi Formation, ranging in age from the Middle to Late Eocene. The NNW-SSE, NNE-SSW, and NW-SE trending faults represent the main trend in the present area. These fault sets are extant on a large scale for numerous kilometers in the study area. Petrographically, three microfacies (F1-F3) were detected during the petrographic investigation of the studied samples, reflect the subtidal shallow reefal and warm platform conditions. XRF analysis shows that SiO2 content is higher in the Qurn Member (the lower member of the Beni Suef Formation). In contrast, CaO content is predominant in the Tarbul Member (the upper member of the Beni Suef Formation) and the Maadi Formation, with some siliciclastic constituents. On the other hand, the Zr content is highest in the study area. Also, some trace elements, such as Ba, V, Sr, and Zn, are prevalent in all studied rocks. The Upper Eocene Maadi Formation has relatively higher U and Th contents than the Middle-Upper Eocene Beni Suef Formation.