| 總結: | The Aterian is a Middle Stone Age technocomplex that occurs throughout North Africa, typically identified by the presence of pedunculates. Due to widespread radiocarbon dating of contaminated samples, most Aterian sites are not well-dated. The use of more appropriate absolute dating techniques, including optically stimulated luminescence (OSL), has renewed interest in the Aterian technocomplex--several sites with remarkable behavioural innovations have been the source of surprisingly early ages.
This OSL dating project had two separate but complementary aims. First, OSL ages were obtained for samples from four significant Aterian sites (Taforalt, Dar es-Soltan I, Rhafas, and Chaperon Rouge II). High density sampling strategies were used in concert with independent dating methods and Bayesian modeling in order to obtain accurate and precise OSL ages. This study suggests that the Aterian technocomplex began by at least 70 ka in Taforalt, though Middle Palaeolithic archaeology exists earlier, and likely before ~100 ka at the coastal site Dar es-Soltan I. Single grain analysis was carried out for a previously dated sample from the open air site Chaperon Rouge II (Rhodes, 1990), and it indicated that the sample was likely highly bioturbated. Conversely, sediment trapped within a potentially Aterian human femur (Rhafas) seems to be less than 10,000 years old, though the bone itself may be older.
Second, the feasibility of imaging ultraviolet OSL via electron-multiplying charge coupled device (EMCCD) cameras was investigated. Key requirements for an OSL imager were evaluated, scientific cameras from several manufacturers were compared, and an optical system was created. Experiments have shown that a back-thinned, back-illuminated EMCCD camera is sensitive enough in the UV regime (365 nm) to successfully detect OSL emissions from natural quartz grains. Additionally, quantitative information can be derived from such image sequences and used to calculate equivalent dose.
|
|---|