Journal of Earth Science, Vol. 28, No. 1, p. 001–008, February 2017 ISSN 1674-487X Printed in China DOI: 10.1007/s12583-016-0906-2 El-Sorogy, A. S., Abd-Elmoneim, M., Mowafi, A., et al., 2017. Facies Analysis and Biostratigraphy of the Miocene Sequence, Cairo- Suez District, Egypt. Journal of Earth Science, 28(1): 1–8. doi:10.1007/s12583-016-0906-2. http://en.earth-science.net Facies Analysis and Biostratigraphy of the Miocene Sequence, Cairo-Suez District, Egypt Abdelbaset El-Sorogy * 1, 2 , Mohamed Abd-Elmoneim 2 , Ahmed Mowafi 2 , Khaled Al-Kahtany 1 , Hisham Gahlan 1 1. Department of Geology and Geophysics, College of Science, King Saud University, Riyadh 11451, Saudi Arabia 2. Geology Department, Faculty of Science, Zagazig University, Zagazig 44519, Egypt Abdelbaset El-Sorogy: http://orcid-org/0000-0003-0283-1433 ABSTRACT: Miocene siliciclastic-carbonate deposits are widely exposed in Cairo-Suez District, Egypt. These deposits are underlain and overlain by continental sediments of Oligocene and post Miocene, re- spectively. Three stratigraphic sections were investigated at Gabals Geneife, Homeira and Gharra. Lithostrtigraphically, the Miocene sequence could be differentiated into two main rock units represent- ing shallow deposits with relatively intermittent deep marine incursions. These are from base to top, Gharra Formation and Genefe Formation. Detailed macrofossils investigations led to the recognition of four macrofossil zones, namely Alectryonella plicatula-Crassostrea frondosa Range Zone, Echinolampas amplus-Scutella ammonis Range Zone, Chlamys (Macrochlamys) sardoa-Chlamys (Argopecten) submalvi- nae Range Zone, and Chlamys gentoni-Pecten (Oppenheimopecten) benedictus-Pecten (P.) ziziniae Assem- blage Zone. Microfacies analysis and identified taxa indicated that the Miocene sequence was deposited in transgressive-regressive cycles ranged from near shore, warm shallow inner to middle shelf marine environments with storm influence during the accumulation of the oyster banks. KEY WORDS: facies analysis, biostratigraphy, Miocene, Cairo-Suez District, Egypt. 0 INTRODUCTION In Egypt, the Miocene rocks are widely distributed covering about 1/8 of the area of the exposed sedimentary rocks. They outcropped mainly in the following areas: north western desert, Cairo-Suez area, Gulf of Suez and Red Sea coastal plain. The Cairo-Suez area is situated at the east of Cairo and extends about 120 km to the city of Suez. It lies between 29º55N–30º20N and 31º15E–32º35E (Fig. 1). The topography of the area is largely controlled by its structure and the relief is generally low except for few hills and small mountains. Topographically, the area is subdi- vided into three ridges crossing the district in a more or less E-W alignment; between these ridges there are two depressions. The Cairo-Suez asphaltic road passes through the southern one. Gabal Ataqa, Gabal Abou Treifiya, Gabal Qattamiya, Gabal Anqabiaya, Gabal Nasuri and Gabal Mokattam form an elongated ridge run- ning parallel to Cairo-Suez High Way depression from east to west and to the south of it (Abou Khadrah et al., 1993). The oldest exposed rocks in the area are of Early Cretaceous age while the youngest rocks are of Quaternary age of synrift sedimentary se- quence (Bruce and Hotzl, 1988). The Miocene rocks of the Cairo-Suez area were the subject of many studies since the last quarter of the 19th century. Most *Corresponding author: elsorogyabd@yahoo.com © China University of Geosciences and Springer-Verlag Berlin Heidelberg 2017 Manuscript received July 9, 2014. Manuscript accepted December 10, 2014. of these studies focused on the stratigraphy and sedimentology with little emphasis on the micro- and macrofossils that could delineate, to a great extent, the age of the different rock units. Therefore, the main target of the present work is to study the facies analysis and biostratigraphy of the Miocene sequence in Cairo-Suez District, Egypt. 1 STUDY SECTIONS The early Middle Miocene is a time of an extensive marine transgression following a major drop of the sea level at the Burdigalian/Langhian transition (Hardenbol et al., 1998; Haq et al., 1987). The Miocene rocks of Cairo-Suez District are differ- entiated into marine and non-marine deposits and have been previously discussed by different authors (e.g., El-Sorogy, 2015, 2002; Tawfik et al., 2015; El-Hedeny, 2005; El-Sorogy et al., 2005; Abdelghany, 2002; Mandic and Piller, 2001; El-Sorogy and Ziko, 1999; Ismail and Abdelghany, 1999; El-Safory and El- Sorogy, 1998; Said and Metwalli, 1964; Said and Yallouze, 1955; Shukri and Akmal, 1953). 1.1 Gabal Geneifa Section This section lies between the exposed Eocene limestones of Gabal Geneifa to the west and Suez-Port Said asphaltic road to the east. It extends between longitudes 32º2030E–32º2230E, and latitudes 30º1220N–30º1320N (Fig. 1). The base of the succes- sion is unexposed. The scarp of Geneifa gets gradually low and low southwards. The lowermost rock samples are available to be collected from a mine near the asphaltic road, south of Geneifa Town. The succession measures a total thickness of 97.1 m (Fig. 2).