Time, Space, and Image Making: Rock Art from the Dhar Tichitt (Mauritania)

Prehistoric images are particularly versatile and difficult to grasp. In a few cases of historical continuity, local cultural glosses provide researchers with a rich corpus of data and help in the interpretation of the imagery. Such approaches contribute to the interpretation of the material in a frozen time perspective. Their impact on the development of archaeological methodologies enabling researchers to deal with strictly prehistoric image making traditions without any known descendant communities remains to be felt. This paper is an attempt to develop a subtle and robust archaeological methodology for the study of prehistoric images. The suggested approaches are replicable, and conclusions are falsifiable.Les images préhistoriques sont particulièrement versatiles, et leur sens difficile à cerner en raison de leur polysémie. Dans une poignée de cas, là ou il y a continuité historique, les chercheurs ont reussi à constituer une riche documentation sur les pratiques culturelles liées à l'utilisation des images. Ils/elles parviennent ainsi à des niveaux d'interpretation très detaillée, dans une conception paradoxalement réifiée des sociétés en question, conservant des pratiques culturelles inchangées pendant des millénaires. L'impact de telles approches sur l'élaboration de bonnes méthodes archéologique est négligeable. Dans la plupart des cas, les images et les vestiges matériels sont le uniques témoins des sociétés préhistoriques étudiées. Cet article s'efforce de developper des méthodes, à la fois subtiles et robustes, permettant une analyse systématique des images préhistoriques. Les méthodes proposées sont réplicables, et les conclusions refutables.     

Are rocks still water‐wet in the presence of dense CO2 or H2S?

The various modes of acid gas storage in aquifers, namely structural, residual, and local capillary trapping, are effective only if the rock remains water‐wet. This paper reports an evaluation, by means of the captive‐bubble method, of the water‐wet character in presence of dense acid gases (CO₂, H₂S) of typical rock‐forming minerals such as mica, quartz, calcite, and of a carbonate‐rich rock sampled from the caprock of a CO₂ storage reservoir in the South‐West of France. The method, which is improved from that previously implemented with similar systems by Chiquet et al. (Geofluids 2007; 7 : 112), allows the advancing and receding contact angles, as well as the adhesion behavior of the acid gas on the mineral substrate, to be evaluated over a large range of temperatures (up to 140°C), pressures (up to 150 bar), and brine salinities (up to NaCl saturation) representative of various geological storage conditions. The water‐receding (or gas‐advancing) angle that controls structural and local capillary trapping is observed to be not significantly altered in the presence of dense CO₂ or H₂S. In contrast, some alteration of the water‐advancing (or gas‐receding) angle involved in residual trapping is observed, along with acid gas adhesion, particularly on mica. A spectacular wettability reversal is even observed with mica and liquid H₂S. These results complement other recent observations on similar systems and present analogies with the wetting behavior of crude oil/brine/mineral systems, which has been thoroughly studied over the past decades. An insight is given into the interfacial forces that govern wettability in acid gas‐bearing aquifers, and the consequences for acid gas geological storage are discussed along with open questions for future work.     

岩画断代研究——科技考古学领域中一个亟待解决的问题

探索和研究表明,岩画断代问题仍然是困扰岩画研究的难题之一,其主要原因是岩画本身不能够提供可供断代的直接依据。本文综述了目前岩画断代研究中经常使用的自然科学和考古学方法及其存在的问题,提出应用AMS14C是今后研究我国岩绘画断代问题的首选方法,解决岩刻画的断代问题则主要有赖于微腐蚀方法。     

Forbidden Images: Rock Paintings and the Nyau Secret Society of Central Malaŵi and Eastern Zambia

This paper examines the rock art of the nyau secret society of eastern Zambia and central Malai. The art dates principally from the nineteenth and early twentieth centuries. It has been known to researchers since the 1970s but has given up few of its secrets. I examine the questions of why the art was made and why the tradition ceased. Key to answering these is the realization that the art belonged to a specific historical and geographic context: the era and area where nyau was forced to become an underground movement because of its suppression by Ngoni invaders, missions, and the later colonial government. The art provides us with detailed insights into the way nyau has served in the process of overcoming and manipulating the traumatic social changes faced by Chea society in the last few centuries.Cet article examine l'art rupestre de la société secrète de nyau au est du Zambia et Malai centrale. L'art date principalement aux dix-neuvième et bas vingtième siècles. Recherchers ont su l'art depuis les années soixante-dix, mais ils ont appris peu de ses secrets. J'examine les questions de pourquoi l'art était fabriquer et pourquoi la tradition a cessé. Pour résoudre ces questions c'est important à réaliser que l'art était à sa place dans un milieu spécifique d'histoire et géographie: au temps et place où nyau était forcer à devenir un mouvement clandestin à cause de sa répression par les envahisseurs Ngoni, les missions et, plus tard, le gouvernement colonial. L'art nous donne les aperçus détaillé sur comment nyau a servi dans le procès à surmonter et manipuler les changements traumatiques que la société Chea a bravé dans les siècles récents.     

Seal on Land, Elk at Sea: Notes on and Applications of the Ritual Landscape at the Seaboard

Ritual landscapes at sea are marked in the cognitive world of coastal people by a primary antagonism between sea and land. This contrast is negotiated by liminal 'foreign' agents, selected for their symbolic adherence to either part. The primary source of maritime culture is fishing as a survival of past hunter-gatherer societies. Forms of religious or magical management of this contrast are manifold, from recent superstitious magic to powerful symbols in ancient worship, objects, art, architecture and cult. Also described are ways of using the sea on land as a magic metaphor and a fundamental point of reference. Related dichotomies and ways of negotiating them, such as the liminal agent, exist elsewhere in the cognitive world of pre-industrial societies, so these ideas could have applications in archaeology.
© 2005 The Nautical Archaeology Society