Mohamed A. Khalifa received his B.S. in geology from Geology Department, Cairo University in 1972, obtained a master's degree in geology from the Faculty of Science, Cairo University in 1977, and received his Ph. D. in sedimentology and stratigraphy from Faculty of Science, Cairo University in 1981. From 1973 to 1978, he worked at the Egyptian Geological Survey. During this period, he drew geological maps using aerial photographs and made a regional correlation of the Mesozoic and Cenozoic rock stratigraphic units in the Western and Eastern Deserts. From 1995 to 1999, he taught at geography department, Imam Mohamed ben Saud University at Al Qassim branch. From 2009 to 2015, he taught at Geology Department, Omar Al Mokhtar University (Libya) at Topruck branch. So far, he has published 87 research papers in the fields of sedimentology, stratigraphy, diagenesis, cyclicity and sequence stratigraphy of the Paleozoic, Mesozoic and Cenozoic rocks from Egypt, Saudi Arabia, Yemen and Jordon. He introduced five stratigraphic rock units in the Egyptian geology (Campanian Ain Giffara, Turonian Naqb Es Sillim, Turonian Khashm El Galala, Lower Eocene Nashfa and Pliocene El Reis formations). Of note, he introduced a new rock unit in the Paleozoic and Mesozoic Eras in Al Qassim Province, Saudi Arabia (Lower Ordovician Anz, Permian Al Watah, Permo-Triassic Al Arid, Upper Triassic Al Adgham and Upper Triassic the Rukhman formations). He is now an emeritus professor at Geology Department, Faculty of Science, Menoufia University, Shiben El Kom, Egypt.