The Pleistocene and Postpleistocene History of the Isthmus of Suez
25
during the Mindel-Riss Interglacial the Isthmus was completely submerged
( + 35 m !), in the Riss-Würm a narrow section of a few kilometers around EI Guisr
and EI Ferdan (Km 64 to 72 of the Canal kilometer count) must have remained
dry. Recently, and following other authors, Fairbridge (1972) concluded that the
highest Mediterranean interglaciallevels might have been only around 20-30 m
above the present main sea-Ievel.
The drying-out of the Eastern Delta branches can be followed historically.
Tbis is especially the case in the Pelusian branch. Judging from the history of the
town of Pelusium (Tel Farama) situated at the opening of tbis branch to the
Mediterranean, the branch must still have been flowing in the earlier Middle Ages
or at least in Roman times (Sneh and Weissbrod, 1973). It still appears under the
name ofBahr Beni Menaga in the data ofthe Arab geograph er Ibn Sirapiun. The
branch of Wadi Tumilat served already in historical times only to carry the
overflow of the Pelusian branch into Lake Timsah and the Bitter Lakes basins.
The Tanitic branch probably disappeared earlier than the Pelusian one, but
remnants of it still continued to carry Nile waters into Lake Menzaleh. It is
interesting to mention that another important Nile branch, the Sebennitic branch,
(which flowed exactly in a South-North direction) dried out in the time between
the classical times and the Arab era.
A second body of evidence results from the geological prospecting of the
Isthmus by Fuchs (1878) in 1864-1865 and the study on the Pleistocene subfossil
molluscs collected on the Isthmus by Issel (1869) and Fischer (1870). In the
Pleistocene sediments ofthe Isthmus-prior to the flooding of the Suez Canal-a
considerable number of recent species of molluscs was found (Fig.9). Three
groups were recognized by the above authors: Red Sea species, Mediterranean
species, and fluviatile, Nile River species.
The Red Sea molluscs found were, among others, Strombus tricornis, Murex
anguliferus, Fusinus marmoratus, Cerithium erythraeonense, Mactra olorina, Circe
pectinata, and Ostreaforskalii. The Mediterranean species found were Purpura hae
mastoma, Murex trunculus, Cerithium vulgatum, Donax venusta, and Ostrea edulis.
The Nile species were Physa contorta, Vivipara unicolor, Spatha rubens, and Etheria semilunata.
These three fossil faunas are distributed as folIows: the Mediterranean species
extend over the Isthmus southward to EI Firdan (about 64 km south of Port Said)
among deposits of sand, sandy clay and gypsum. The Red Sea fauna extends
northward from Suez to Kabrit, a distance of about 40 km. The central 60 km
exhibit freshwater fauna or an interbedding of freshwater and Red Sea species.
The sill of EI Guisr-at an elevation of 23 m-has freshwater deposits and a
similar substrate is also found in most of the Lake Timsah area. However, as one
advances south, the freshwater fauna is more and more interlaminated with an
increasingly rich Red Sea fauna. The Red Sea fauna becomes dominant in the
basin ofthe Great Bitter Lake and exclusive in the Little Bitter Lake.
The most obvious interpretation ofthe Fuchs-Issel-Fischer findings would be
that of a slightly more transgressive Mediterranean and Red Sea and an interposed lagoon area with brackish stratification [fresh at the surface and marine on
the bottom as suggested by W. Steinitz (1929)] in contact with the Red Sea
(Fig.10).
25
during the Mindel-Riss Interglacial the Isthmus was completely submerged
( + 35 m !), in the Riss-Würm a narrow section of a few kilometers around EI Guisr
and EI Ferdan (Km 64 to 72 of the Canal kilometer count) must have remained
dry. Recently, and following other authors, Fairbridge (1972) concluded that the
highest Mediterranean interglaciallevels might have been only around 20-30 m
above the present main sea-Ievel.
The drying-out of the Eastern Delta branches can be followed historically.
Tbis is especially the case in the Pelusian branch. Judging from the history of the
town of Pelusium (Tel Farama) situated at the opening of tbis branch to the
Mediterranean, the branch must still have been flowing in the earlier Middle Ages
or at least in Roman times (Sneh and Weissbrod, 1973). It still appears under the
name ofBahr Beni Menaga in the data ofthe Arab geograph er Ibn Sirapiun. The
branch of Wadi Tumilat served already in historical times only to carry the
overflow of the Pelusian branch into Lake Timsah and the Bitter Lakes basins.
The Tanitic branch probably disappeared earlier than the Pelusian one, but
remnants of it still continued to carry Nile waters into Lake Menzaleh. It is
interesting to mention that another important Nile branch, the Sebennitic branch,
(which flowed exactly in a South-North direction) dried out in the time between
the classical times and the Arab era.
A second body of evidence results from the geological prospecting of the
Isthmus by Fuchs (1878) in 1864-1865 and the study on the Pleistocene subfossil
molluscs collected on the Isthmus by Issel (1869) and Fischer (1870). In the
Pleistocene sediments ofthe Isthmus-prior to the flooding of the Suez Canal-a
considerable number of recent species of molluscs was found (Fig.9). Three
groups were recognized by the above authors: Red Sea species, Mediterranean
species, and fluviatile, Nile River species.
The Red Sea molluscs found were, among others, Strombus tricornis, Murex
anguliferus, Fusinus marmoratus, Cerithium erythraeonense, Mactra olorina, Circe
pectinata, and Ostreaforskalii. The Mediterranean species found were Purpura hae
mastoma, Murex trunculus, Cerithium vulgatum, Donax venusta, and Ostrea edulis.
The Nile species were Physa contorta, Vivipara unicolor, Spatha rubens, and Etheria semilunata.
These three fossil faunas are distributed as folIows: the Mediterranean species
extend over the Isthmus southward to EI Firdan (about 64 km south of Port Said)
among deposits of sand, sandy clay and gypsum. The Red Sea fauna extends
northward from Suez to Kabrit, a distance of about 40 km. The central 60 km
exhibit freshwater fauna or an interbedding of freshwater and Red Sea species.
The sill of EI Guisr-at an elevation of 23 m-has freshwater deposits and a
similar substrate is also found in most of the Lake Timsah area. However, as one
advances south, the freshwater fauna is more and more interlaminated with an
increasingly rich Red Sea fauna. The Red Sea fauna becomes dominant in the
basin ofthe Great Bitter Lake and exclusive in the Little Bitter Lake.
The most obvious interpretation ofthe Fuchs-Issel-Fischer findings would be
that of a slightly more transgressive Mediterranean and Red Sea and an interposed lagoon area with brackish stratification [fresh at the surface and marine on
the bottom as suggested by W. Steinitz (1929)] in contact with the Red Sea
(Fig.10).