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The excavation at Takarkori rock shelter is part of a long-term study of Holocene cultural dynamics in southwest Libya begun in the early 1990s. With a rich Holocene occupation, the area is one of the key spots for reconstruction of human occupation of the last 10,000 years. In this region, similar to the case in the rest of the Sahara, most of the data come from surface investigations at open-air sites, while excavated caves and rock shelters provide just a few. Although less exposed than open-air sites, Holocene archaeological deposits in Saharan caves and rock shelters are characterized by a fairly dynamic nature. Loose sediments, coupled with variability of human occupations and magnitude of natural agents, determine multiple alterations to the archaeological deposits in sheltered sites. In this paper, we present the nature and meaning of the archaeological deposits at Takarkori rock shelter, where a relatively large area has been recently excavated, showing a stratigraphic sequence extending from c. 9,000 to 4,200 BP, unevenly represented by several occupation pulses. In order to sharpen understanding of the development of human occupation at this site, specific procedures for the study and recording of the archaeological deposit have been developed, along with a program of extensive radiocarbon dating. Data from the Takarkori sequence ultimately will be integrated with available published stratigraphies from the Acacus Mountains, with the aim of reviewing the results from past excavations. [ABSTRACT FROM AUTHOR]

In the prehistoric green Sahara of Holocene North Africa-in contrast to the Neolithic of Europe and Eurasia-a reliance on cattle, sheep and goats emerged as a stable and widespread way of life, long before the first evidence for domesticated plants or settled village farming communities. The remarkable rock art found widely across the region depicts cattle herding among early Saharan pastoral groups, and includes rare scenes of milking; however, these images can rarely be reliably dated. Although the faunal evidence provides further confirmation of the importance of cattle and other domesticates, the scarcity of cattle bones makes it impossible to ascertain herd structures via kill-off patterns, thereby precluding interpretations of whether dairying was practiced. Because pottery production begins early in northern Africa the potential exists to investigate diet and subsistence practices using molecular and isotopic analyses of absorbed food residues. This approach has been successful in determining the chronology of dairying beginning in the 'Fertile Crescent' of the Near East and its spread across Europe. Here we report the first unequivocal chemical evidence, based on the ?13C and ?13C values of the major alkanoic acids of milk fat, for the adoption of dairying practices by prehistoric Saharan African people in the fifth millennium bc. Interpretations are supported by a new database of modern ruminant animal fats collected from Africa. These findings confirm the importance of 'lifetime products', such as milk, in early Saharan pastoralism, and provide an evolutionary context for the emergence of lactase persistence in Africa. [ABSTRACT FROM AUTHOR]

Rock shelters in the central Saharan massifs preserve anthropogenic stratigraphic sequences that represent both a precious archive for the prehistory of the region and a powerful proxy data for Holocene palaeoenvironments. The geoarchaeological (micromorphology) and archaeobotanical (pollen analysis) approaches were integrated to investigate the anthropogenic sedimentary sequence preserved within the Takarkori rock shelter, a Holocene archaeological site located in the Libyan central Sahara (southern Tadrart Acacus massif). The site was occupied throughout the Early and Middle Holocene (African Humid Period) by groups of hunter–gatherers before and by pastoral communities later. The investigation on the inner part of the sequence allows to recognize the anthropogenic contribution to sedimentation process, and to reconstruct the major changes in the Holocene climate. At the bottom of the stratigraphic sequence, evidence for the earliest frequentation of the site by hunters and gatherers has been recognized; it is dated to c. 10,170 cal yr BP and is characterized by high availability of water, freshwater habitats and sparsely wooded savannah vegetation. A second Early Holocene occupation ended at c. 8180 cal yr BP; this phase is marked by increased aridity: sediments progressively richer in organics, testifying to a more intense occupation of the site, and pollen spectra indicating a decrease of grassland and the spreading of cattails, which followed a general lowering of lake level or widening of shallow-water marginal habitats near the site. After this period, a new occupational phase is dated between c. 8180 and 5610 cal yr BP; this period saw the beginning of the frequentation of pastoral groups and is marked by an important change in the forming processes of the sequence. Sediments and pollen spectra confirm a new increase in water availability, which led to a change in the landscape surrounding the Takarkori rock shelter with the spreading of water bodies. The upper part of the sequence, dating between c. 5700 and 4650 cal yr BP records a significant environmental instability towards dryer climatic conditions, consistent with the end of the African Humid Period. Though some freshwater habitats were still present, increasing aridity pushed the expansion of the dry savannah. The final transition to arid conditions is indicated by the preservation of ovicaprines dung layers at the top of the sequence together with sandstone blocks collapsed from the shelter's vault. On the contrary, the outer part of the sequence preserves a significantly different palaeoenvironmental signal; in fact, the surface was exposed to rainfall and a complex pedogenetic evolution of the sequence occurred, encompassing the formation of an argillic laminar horizon at the topsoil, the evolution of a desert pavement, and the deposition of Mn-rich rock varnish on stones. These processes are an effect of the general environmental instability that occurred in the central Sahara since the Middle Holocene transition. Finally, the local palaeoclimatic significance of the sequence fits well with Holocene regional and continental environmental changes recorded by many palaeohydrological records from North Africa. This highlights the potential of geoarchaeological and archaeobotanical investigations in interpreting the palaeoenvironmental significance of anthropogenic cave sediments in arid lands. [ABSTRACT FROM AUTHOR]