Following anticipatory reports by Arkell (1949) wc have carried out gcoarcheological researches in the Pleistoccne deposits of the middle Atbara valley in the karih region near Khasma El Ghirba. Starting from the Atbara stream bed abundant lithic artifacts and several mammal bones have been found embedded in the lower and middle portion ofa 30 m thick succession. The sequence starts with two levels (Atbara l and 2) of polygcnic pcbbles, each 2-3 m thick, locally well cemented and rich in sandy matrix. Pebbles are gcncrally wcll rounded, reach a maximum size of 20 cm and derive mainly from the Precambrian basement and, subordinately, from the siliceous Tertiary Hudi Formation. Atbara 1 is scparated from the overlying Atbara 2 by 4 to 5 meters of cross-laminated sands and massive silts with pedogenic features, such as calcretes, rhizoconcretions. and Mn nodules. The Atbara 2 is toppcd by 5 meters of cross-bedded sands_ silts and pebbly sandstones. Fresh-water oysters reefs have grown above this level and constitute a widespread keybed. The suecession makes upward transition into yellowish to light brown massive or poorly horizontally laminated silts with thin sandy levels and caliches, and temiinates with sheets of light gray and coarse sands, 2 m thick. Atbara l yielded choppers and flakes, while handaxes, choppers and flakes were found in the Atbara 2, in the oyster keybed and, more sparsely. in the immediately overlying sediments. This lithic assemblage can bc referred to the Mode 2 complexes (Acheulean) of East Africa. Atbara 2 provided a rich mamma] fauna including Elephas (ff E.rcc/ti, Hippopotamidae indet., Bovidae indet. I (middle sizcd), Bovidae indet. ll (cfr. Pelorovis sp.). Although based on preliminary field determinations, the fauna! assemblage points to an Early to Middle Pleistocene age. A flood plain crossed by braided streams is indicated by the sedimentological features of the succession which was developing in an intemiediate to distal portion of the paleo Gash-Barka deltaic system. The latter prograded northwest toward the Sudd lake which at that time was covering a wide area of Central Sudan. The environment in which Homo was living was a savannah with perennial and/or ephemeral streams and scattered water pools. Along possible pathways of northward hominid migration the Khasma El Ghirba site in sub-Saharan Africa is the closest to the East African rifts.

Lithic artefacts, fossil mammals and paleoenvironment in the Pleistocene of the Middle Atbara Valley (Eastern Sudan) / E. Omer; E.Abbate; M.Papini; L.Rook; M.Sagri. - STAMPA. - 8th International Conference on Geology of the Arab World (GAW 8):(2006), pp. 30-31. (Intervento presentato al convegno 8th International Conference on Geology of the Arab World tenutosi a Cairo nel 13-16 febbraio 2006).

Lithic artefacts, fossil mammals and paleoenvironment in the Pleistocene of the Middle Atbara Valley (Eastern Sudan)

ABBATE, ERNESTO
;
PAPINI, MAURO;ROOK, LORENZO;SAGRI, MARIO
2006

Abstract

Following anticipatory reports by Arkell (1949) wc have carried out gcoarcheological researches in the Pleistoccne deposits of the middle Atbara valley in the karih region near Khasma El Ghirba. Starting from the Atbara stream bed abundant lithic artifacts and several mammal bones have been found embedded in the lower and middle portion ofa 30 m thick succession. The sequence starts with two levels (Atbara l and 2) of polygcnic pcbbles, each 2-3 m thick, locally well cemented and rich in sandy matrix. Pebbles are gcncrally wcll rounded, reach a maximum size of 20 cm and derive mainly from the Precambrian basement and, subordinately, from the siliceous Tertiary Hudi Formation. Atbara 1 is scparated from the overlying Atbara 2 by 4 to 5 meters of cross-laminated sands and massive silts with pedogenic features, such as calcretes, rhizoconcretions. and Mn nodules. The Atbara 2 is toppcd by 5 meters of cross-bedded sands_ silts and pebbly sandstones. Fresh-water oysters reefs have grown above this level and constitute a widespread keybed. The suecession makes upward transition into yellowish to light brown massive or poorly horizontally laminated silts with thin sandy levels and caliches, and temiinates with sheets of light gray and coarse sands, 2 m thick. Atbara l yielded choppers and flakes, while handaxes, choppers and flakes were found in the Atbara 2, in the oyster keybed and, more sparsely. in the immediately overlying sediments. This lithic assemblage can bc referred to the Mode 2 complexes (Acheulean) of East Africa. Atbara 2 provided a rich mamma] fauna including Elephas (ff E.rcc/ti, Hippopotamidae indet., Bovidae indet. I (middle sizcd), Bovidae indet. ll (cfr. Pelorovis sp.). Although based on preliminary field determinations, the fauna! assemblage points to an Early to Middle Pleistocene age. A flood plain crossed by braided streams is indicated by the sedimentological features of the succession which was developing in an intemiediate to distal portion of the paleo Gash-Barka deltaic system. The latter prograded northwest toward the Sudd lake which at that time was covering a wide area of Central Sudan. The environment in which Homo was living was a savannah with perennial and/or ephemeral streams and scattered water pools. Along possible pathways of northward hominid migration the Khasma El Ghirba site in sub-Saharan Africa is the closest to the East African rifts.
2006
8th International Conference on Geology of the Arab World (GAW 8)
8th International Conference on Geology of the Arab World
Cairo
E. Omer; E.Abbate; M.Papini; L.Rook; M.Sagri
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Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/348788
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