Pliocene/pleistocene formations in the lower omo basin, southern Ethiopia

Journal ArticleFollowing a two month geological reconnaissance by one of us (FHB) in 1966, four seasons of fieldwork by members of the Omo Research Expedition has added greatly to our previous, scanty knowledge of the late Cenozoic history of the lower Omo basin in southern Ethiopia. Eduard Suess (in: von Hohnel et al., 1891) was the first to associate the lower Omo basin with the Eastern Rift Valley after the explorations of the Teleki-von Hohnel expedition in 1888 (von Hohnel, 1938). M. Sacchi, geologist with the Bottego expedition, subsequently noted the occurrence of flat-lying, undeformed sediments in the basin and these were reported on by Angelis d'Ossat and Millosevich (Angelis d'Ossat and Millosevich, 1900; Vannutelli and Citerna, 1899). These sediments have since proved to represent an extensive suite of later Pleistocene to recent strata deposited during major northward extensions of Lake Rudolf and of the delta and floodplain of the Omo River (Butzer and Thurber, 1969). E. Brumpt first collected fossils from older, tectonically disturbed sediments in the lower Omo basin when the Bourg de Bozas (Bourg de Bozas, 1903) expedition traversed the area at the turn of the century. Haug (1912, p. 1727) recognized that these specimens were of some importance in the study of the Pleistocene of eastern Africa. Two decades later, the late Prof. C. Arambourg (Arambourg and Jeannel, 1933) made a geological reconnaissance of a part of this area and amassed a substantial collection of vertebrate fossils from these deformed deposits, which he termed the Omo Beds. His pioneer work placed on record the richness and diversity of this fauna which he regarded as of earlier Pleistocene age

Chronology

Journal ArticleThe boundaries of the Lower Omo Basin have been mapped by Fuchs (1939) and by Butzer (1970, 1971) in a general way. The structural features and physiography of the eastern and central part of the Lower Omo Basin are best expressed on the maps of Davidson et al. (1973). Walsh and Dodson (1969) have mapped the geology of the North Turkana District of Kenya. East of Lake Turkana the geology is summarized by Vondra and Bowen (1976), and Vondra, Burggraf and White (1978). The Ilemi Triangle in southern Sudan remains poorly known geologically, but some information is presented by Fuchs (1939), and by Arambourg (1943). More recently Baker et al. (1972) and Cerling and Powers (1977) have provided general summaries of the structural evolution of this part of East Africa

The lower Omo basin

Journal ArticleThe boundaries of the Lower Omo Basin have been mapped by Fuchs (1939) and by Butzer (1970, 1971) in a general way. The structural features and physiography of the eastern and central part of the Lower Omo Basin are best expressed on the maps of Davidson et al. (1973). Walsh and Dodson (1969) have mapped the geology of the North Turkana District of Kenya. East of Lake Turkana the geology is summarized by Vondra and Bowen (1976), and Vondra, Burggraf and White (1978). The Ilemi Triangle in southern Sudan remains poorly known geologically, but some information is presented by Fuchs (1939), and by Arambourg (1943). More recently Baker et al. (1972) and Cerling and Powers (1977) have provided general summaries of the structural evolution of this part of East Africa

La vallée de l'Escaut à Pont-à-Chin

The sudden opening of a karst pipe in the abandoned bed of the Scheldt River has exposed 8 m ofHolocene deposits; their stratigraphy, archaeological contents, fossil fauna and flora are studied here. A well dated early occupation is from the First Iron Age to Early La Tène (around 650-450 B.C.), a second one from Roman times (around 50-200 A.D.); they permit a close control of the14 C dates, which are systematically too old, due to reworking in the stream. Vertebrate and molluscan assemblages are discussed separatel

First GIS analysis of modern stone tools used by wild chimpanzees (Pan troglodytes verus) in Bossou, Guinea, West Africa

Stone tool use by wild chimpanzees of West Africa offers a unique opportunity to explore the evolutionary roots of technology during human evolution. However, detailed analyses of chimpanzee stone artifacts are still lacking, thus precluding a comparison with the earliest archaeological record. This paper presents the first systematic study of stone tools used by wild chimpanzees to crack open nuts in Bossou (Guinea-Conakry), and applies pioneering analytical techniques to such artifacts. Automatic morphometric GIS classification enabled to create maps of use wear over the stone tools (anvils, hammers, and hammers/anvils), which were blind tested with GIS spatial analysis of damage patterns identified visually. Our analysis shows that chimpanzee stone tool use wear can be systematized and specific damage patterns discerned, allowing to discriminate between active and passive pounders in lithic assemblages. In summary, our results demonstrate the heuristic potential of combined suites of GIS techniques for the analysis of battered artifacts, and have enabled creating a referential framework of analysis in which wild chimpanzee battered tools can for the first time be directly compared to the early archaeological record.Leverhulme Trust [IN-052]; MEXT [20002001, 24000001]; JSPS-U04-PWS; FCT-Portugal [SFRH/BD/36169/2007]; Wenner-Gren Foundation for Anthropological Researc