The Maqfi section outcrops in a conspicuous escarpment 400 km. S. 41° 00’ W. of Cairo, and 69 km. N. 65° 00’ E. of the village of Qasr Farafra, Farafra Oasis, Egypt. Nineteen species of Foraminifera from the Upper Cretaceous and 112 species from the Lower Tertiary of this section are recorded and illustrated. Forty new species have been systematically described. Eight species have been given letter designations because incomplete data do not permit identification or naming. The results of this analysis should serve as control for future micropaleontologic and stratigraphic investigations of the Western Desert of Egypt and adjacent areas of North Africa.
The Maqfi section involves an Upper Cretaceous unit (A) and four Lower Tertiary units (IV, III, II, and I). The lowest exposed Cretaceous strata (Unit A) consist of 150 feet of white, massive chalk and chalky limestone containing abundant Globotruncana and Gümbelina. The lowest Tertiary strata (Unit IV) in the section attains a thickness of 72 feet, consists of medium-gray, moderately bedded, calcareous shale to impure limestone, and is paleontologically identified by an abundance of Globorotalia velascoensis and by the absence of Globotruncana and Gümbelina. Unit IV is separated from the overlying Unit III by an erosional surface and by a major paleontologic break. Its lower boundary, marking the base of the Tertiary as assumed in this paper, is believed to involve disconformable relationships with Unit A of the Cretaceous.
Deposits of Unit III, consisting of 7 feet of hard, light-gray, nummulitic limestone, are unconformably overlain by the Esna beds (Unit II) which consist of 433 feet of soft, fissile, gray-green, highly foraminiferal shale that has been subdivided into several distinct microfaunal intervals. The Esna grades transitionally upward into the massive- to thick-bedded escarpment-forming limestones of Unit I containing abundant Nummulites, Flosculina, and Operculina, and a well-developed molluscan fauna.
This paper emphasizes the distribution and development of the small Foraminifera of the Esna shale; moderate consideration is given the Cretaceous microfaunas. The large Foraminifera (Flosculina and Nummulites) of the Maqfi section are not systematically treated.
The microfaunal subdivisions of the Esna shale as defined in this paper should not be considered as possessing zonal status until additional detailed regional investigations of this portion of the Tertiary have been made in other parts of Egypt and adjacent areas.
The Cretaceous-Tertiary boundary (base of Unit IV) in the Maqfi section conforms with that assumed by some workers at various localities in the Middle East.