Nubian Sandstone Gr

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). The term was extended into Libya by Desio (1935) and Sandford (1935). In Libya the term Nubian Sandstone was applied to all continental beds between the marine Carboniferous and marine Cretaceous (Conant & Goudarzi, 1967), therefore it includes the Continental post-Tassilien and Continental Intercalcaire of the Central Sahara.

“In the Kufrah Basin the equivalent of the Zarzaitine, Taouartine, and Messak formations of Murzuq Basin and equivalents are represented by the so-called Nubian Sandstone.

The Nubian succession was divided by Wacrenier (1958), Klitzsch (1966), and De Lestang (1965, 1968) in the southwestern Kufrah Basin in the Borkou area near the Libyan-Chad border in ascending order into the Soeka Fm, Lakes Fm (formation de lacs), Ounianga Fm, Chieun Fm, and Tekro Fm. On the western side of the Kufrah Basin in northern Chad the Soeka Fm is absent and the Lakes Fm and Ounianga Fm are replaced by the Ouadi Mouro Fm and Ehi Micha Fm, respectively (De Lestang, 1965, 1968).” (Tawadros, 2011). [Hence, the Nubian Sandstone is classified as a Group here.]

Synonym:

References: Tawadros, 2011

Lithology and Thickness: The Nubian Sandstones Fm is about 150m-1500m thick, and is made up of continental sandstones, siltstones, and limestones at the base, marine evaporites, shales, and dolomitic limestones in the midsection, and fluvial deposits of the “Eosahabi” paleo-river system towards the top (Schmeider et al., 2009).

Lithology-pattern: Clayey sandstone

Relationships and Distribution:

Lower contact:

It unconformably overlies the Dalma Fm.

Upper contact:

It is unconformably overlain by the Wadis Deposits Fm.

Regional extent: southeast Libya (also in the Northwestern Chad and Northeastern Sudan in basins known as Erdis and Mourdi basins, respectively). A related Nubian sandstone facies spans much of eastern Egypt and western Libya.

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Fossils:

Age: Jurassic through Early Cretaceous. See individual formations.

Age span:

Beginning stage: Hettangian

Fraction up in beginning stage: 0.00

Beginning date (Ma):

Ending stage: Cenomanian

Fraction up in ending stage: 1.0

Ending date (Ma):

Depositional setting: Continental eolian to fluvial deposits.

Depositional-pattern:

Additional Information:

It is of archeological and historical interest that the mostly hard and massive Nubian Sandstone of Jebel Silsila, north of Aswan in Egypt, was heavily quarried by the Ancient Egyptians for the construction of temples (Beadnell, 1905a, Klemm & Klemm, 2001).

Extracts from Tawadros (2011; Geology of North Africa):

“Two major problems existed with the Egyptian [and Libyan] geology and persisted for over a century. The first of these two problems is famous worldwide and deals with the Nubian Sandstone enigma.

Eduard Rüppell from the Senkenberg Museum, Frankfurt, began his work in Egypt in 1826. In 1837, Russegger introduced the term “Cataract Sandstone” in Upper Egypt, which he subsequently changed in 1842 into the “Nubian Sandstone” and initiated one of the most enduring controversies in the history of geology in North Africa.”

Russegger had introduced the name in 1837 to describe some sandstones exposed in Nubia, but soon thereafter, the term was applied to any problematic sandstones throughout the stratigraphic column in areas extending over the stretch of North Africa, Sudan, Jordan, and Saudi Arabia. [The second problem deals with the Upper Cretaceous-Lower Tertiary boundary which revolves around the definition of the so-called “Esna Shale”.] Pomel (1877) realized that the Nubian Sandstone included sediments of various ages. This name was used by Beadnell, Baron, and Hume in the International Geological Conference in Paris in 1900 and by Blanckenhorn (1902). However, it was not until 1905 that Beadnell introduced the name formally.

Extensive efforts made in the late 1970s and early 1980s were consecrated to the solution of the Nubian Sandstone controversy. Klitzsch et al. (1979) and Ward & McDonald (1979) attempted to subdivide the Nubian Sandstone in the Western and Eastern Deserts, respectively, and represented a major step toward solving the Nubian Sandstone controversy. Ironically, Egypt had to wait for another German “expedition” to tackle the Nubian puzzle. In 1985, a German multidisciplinary team made regional studies of the Nubian Sandstone in southern of Egypt. The results of the German Special Research Project, supported by the German Research Foundation until 1987 were published in volumes 50 and 75 of the Berliner Geowissenschaftliche Abhandlungen.

The Gargaf Group was introduced by Burollet (1960) for Cambro-Ordovician succession in West Libya to include the upward succession of the Hassaouna Fm, Haouaz Fm, Melez Chograne Fm, and Memouniat Fm. A symposium was held at the University of Libya, and the proceedings of the symposium were published in 1971 under the title “Geology of Libya”, edited by C. Gray. Hea (1971) attempted to differentiate between Nubian Gr and Gargaf Gr quartzites based on petrography, which inspired the paper by Tawadros et al. (2001).

Upper Cretaceous (Cenomanian-Santonian) sediments in southern Egypt are composed mainly of sandstones which were included in the “Nubian Sandstone” by earlier workers. Later work however has shown that these sandstones can be divided into several distinct mappable units, hence eliminating much of the confusion in the Egyptian geology which resulted from the use of the term Nubian Sandstone. Klitzsch et al. (1979) suggested the use of the name “Nubia Group”, to include Jurassic to Late Cretaceous rocks overlying the Precambrian basement or Paleozoic beds and underlying Lower Maastrichtian or Tertiary sediments in Southern Egypt.

In 2001, Tawadros published “Geology of Egypt and Libya”, with the main objective to review the geology of the two countries in the context of global and local tectonics and the stratigraphic nomenclature, and to tackle some of the chronic stratigraphic problems, such as the Nubian Sandstone, the Esna Shale, and Paleozoic and Lower Cretaceous quartzites and sandstones.