Investigating the resetting of OSL signals in rock surfaces

There are many examples of buried rock surfaces whose age is of interest to geologists and archaeologists. Luminescence dating is a potential method which can be applied to dating such surfaces; as part of a research project which aims to develop such an approach, the degree of resetting of OSL signals in grains and slices from five different cobbles/boulders collected from a modern beach is investigated. All the rock surfaces are presumed to have been exposed to daylight for a prolonged period of time (weeks to years). Feldspar was identified as the preferred dosimeter because quartz extracts were insensitive. Dose recovery tests using solar simulator and IR diodes on both K-feldspar grains and solid slices taken from the inner parts of the rocks are discussed. Preheat plateau results using surface grains and slices show that significant thermal transfer in naturally bleached samples can be avoided by keeping preheat temperatures low. Equivalent doses from surface K-feldspar grains were highly scattered and much larger than expected (0.02 Gy to >100 Gy), while solid surface slices gave more reproducible small doses (mean = 0.17±0.02 Gy, n = 32). Neither crushing nor partial bleaching were found to be responsible for the large scattered doses from grains, nor did the inevitable contribution from Na-feldspar to the signal from solid slices explain the improved reproducibility in the slices. By modelling the increase of luminescence signal with distance into the rock surface, attenuation factors were derived for two samples. These indicate that, for instance, bleaching at a depth of 2 mm into these samples occurs at about ∼28% of the rate at the surface. We conclude that it should be possible to derive meaningful burial doses of >1 Gy from such cobbles; younger samples would probably require a correction for incomplete bleaching.     

The ancient Greek names “Magnesia” and “Magnetes” and their origin from the magnetite occurrences at the Mavrovouni mountain of Thessaly,central Greece. A mineralogical–geochemical approach

Pliny the Elder (first century A.D.) mentioned that the Thessalian magnetite from Magnesia in ancient Greece was second in quality after the Ethiopic. This magnetite should be related with the origin of the Homeric Magnetes of the eighth century B.C. who lived around Ossa mountain in central Greece. A new euhedral magnetite occurrence derived from the Kampitsios area at the north-western slopes of Mavrovouni mountain in “Amyrikon Pedion”, probably shows that this region should have been connected with the origin of the Homeric Magnetes. The magnetites under study are found as porphyroblasts in the talc schists. They are almost pure with rare inclusions, mainly ilmenite, rutile, pseudorutile and a PbO phase. The alteration of magnetite to hematite is restricted only along the fissures and cracks as well as along the rims, forming very thin films of a few micrometres in thickness. Microprobe analyses showed that the magnetites are almost pure and they contain only traces of Cr₂O₃ (1.01–3.41%). The high-quality magnetites of Kampitsios could be probably related with those mentioned by Pliny, and they should be related with the origin of the Homeric Magnetes of the eighth century B.C. who lived around Ossa mountain in Thessaly.     

Coping with Peripheralization: Governance Response in Two German Small Cities

Urban governance processes and strategies in small cities in times of an integrated global economy have received little attention in urban research. However, in Germany as elsewhere they form the backbone of the urban system. On the basis of research in two small German cities—Pirmasens and Völklingen—this paper discusses local governance approaches in reaction to peripheralization. Peripheralization here is defined as a process of out-migration, dis-connection, dependency and stigmatization. The two case studies show quite different patterns of political governance. Pirmasens demonstrates a collective local project on how to deal with structural change, while Völklingen shows a more fragmented approach to overcoming peripheralization. These different political reactions are analysed and related to aspects of specific local settings. It is to be hoped that in future cohesion policy at the European level, but also on the respective national levels, more active policies will be targeted towards nurturing place-based opportunities for small cities.     

Populations and Climatic Evolution in North Tropical Africa from the End of the Neolithic to the Dawn of the Modern Era

At the end of the Neolithic Era, during the third millennium BCE, there were fewer humid periods, and the sub-Saharan and Sahelian zones from the Atlantic to Lake Chad assumed their current geographical form. Since then, the climate has continued undergoing major variations. The succession of climatic episodes, humid or dry, is pointed out along with the episodes’ complex interactions. These variations are placed in parallel to cultural phases of evolution in archaeology and history. Climate-related events have always had heavy consequences on the peopling of this vast region, often subject to extreme natural conditions. The relative synchronism between the principal cultural trends from west to east across the Sahel seems to have often been subject to swings in the climate and the resulting environmental changes.     

Lithic Economy and Specialized Activities Among the Iberomaurusian Populations of Tamar Hat Rockshelter (Northeastern Algeria)

Tamar Hat rockshelter (Béjaïa, northeastern Algeria) has yielded a lithic assemblage showing general characteristics of an Iberomaurusian Early Late Stone Age nature. Specific “becs,” which we shall call “becs of Tamar Hat,” appear as an important component of the assemblage in the upper occupations, which occurred at the end of Late Glacial Maximum. These becs, from a technological point of view and especially by their shaping processes, constitute a reliable reference collection, though showing morphological variability resulting in part to the reduction process. The use-wear analysis conducted, based on a microscopic examination validated by experimentation, testifies the becs would have functioned for engraving hard bone, such as those of deer. Other scars observed on the sharp edge and lower face near the active portion of the tool are caused by hafting. Hence, the results of the technological and functional analyses of the becs from Tamar Hat reveal the presence of specialized activities in the upper occupations, related to the animal bone processing. These results are supported by the archaeozoological study, which confirms that the site functioned as a seasonal habitat, where Megacerin deer was exploited in the upper occupations for utilitarian, non-food purposes. The emergence of the use of the becs of Tamar Hat is synchronous with the end of the Upper Paleolithic, prior to the expansion of bec use in the Upper Magdalenian of Europe, where technical and stylistic convergences were observed. This raises the question of the emergence of these lithic implements in North Africa and the possible spread of similar industries elsewhere.