PETROGRAPHY AND DIAGENESIS OF CARBONATE ROCKS FROM GEBEL NOGRA-RAMLIYA- AKHEIDER RIDGE, WEST OF THE GULF OF SUEZ SAMIR. A. AWAD*, MARYAM.A.EL-HEFNAWI** and SAID.D. ABA-YAZEED** *Department of Geology, Faculty of Science, Ain Shams University  ** Department of Geological and Geophysical Sciences, NRC, Dokki, Cairo The present work deals with the petrography and diagenesis of the Middle and Upper Eocene carbonates from Gebel Akheider area, west of Gulf of Suez. Middle Eocene carbonates consist mainly of biomicrite, micrite and biosparite, while Upper Eocene carbonates consist of wide variety of carbonate rocks ranging from sandy-clayey dolomitic limestone to clayey and/or sandy-clayey dolostone. The rocks are subjected to extensive diagenetic processes, the most important of which are micritization, cementation, neomorphism, dissolution and precipitation, dolomitization and dedolomitization. In addition, two other diagenetic features, namely blackening of the surface of carbonate rocks and the presence of chert nodules are also recorded. The carbonates of Middle Eocene are represented by low magnesian calcite, while the non-carbonate minerals consist mainly of quartz. Upper Eocene carbonates consist of calcite and dolomite, while the non-carbonate minerals are represented by quartz, gypsum and clay minerals. The main clay minerals are kaolinite and less commonly montmorillonite.