LES ORTSTEINS DU QUÉBEC: RÉPARTITION GEOGRAPHIQUE, RELATIONS GÉOMORPHOLOGIQUES ET ESSAI DE DATATION

Ce travail porte sur I'extension géographique des orts-teins au Québec et vise à déterminer les causes de leur répartition principalement pour la Côte-Nord du Saint-Laurent. Les données ont été puisées en partie dans des rapports pédologiques publiés sur le Québec, mais aussi observées dans des sites d'échantillonnage sur la Côte-Nord du Saint-Laurent, l'île d'Anticosti et en Gaspésie. Par ailleurs, pour les datations au ¹⁴C, six sites d'echantillonnage ont été choisis sur la Côte-Nord. Les résultats indiquent que les ortsteins se développent sous toutes les latitudes au sud de 55e parallèle et sous différentes conditions physiographiques et géologiques. On les retrouve aussi bien sur des silts sableux que sur des graviers grossiers et leur présence est favorisée lorsqu'il y a fluctuation de la nappe d'eau. Les datations au ¹⁴C ont donné des âges relativement jeunes pour les ortsteins, soit moins de 420 ans bp, indiquant qu'il y a une migration active de la matière organique dans les horizons concrétionnés. The present paper concerns the geographic delimitation of ortsteins in Québec and deals with the causes of their distribution mainly for the North Shore of the St. Lawrence River. Data was gathered in part in published geological reports in Quebec, and also acquired in the field along the North Shore of the St. Lawrence River, Anticosti Island, and in the Gaspé Peninsula. Furthermore, six study sites were selected for dating by ¹⁴C along the North Shore. Results indicate the ortsteins develop under all latitudes south of the 55th parallel and under different physiographic and geological conditions. They can be found on both sandy silts and coarse gravels, and their presence is enhanced whenever the water level fluctuates. ¹⁴C datings give relatively young ages for ortsteins, less than 420 years BP, indicating that an active migration of organic matter occurred in the indurated horizons.     

Environmental changes in the Maryut lagoon (northwestern Nile delta) during the last ∼2000 years

Here, we interpret the evolution of Maryut lagoon (Egypt) during the past ∼2000 years. Chronostratigraphy and laboratory analyses have enabled us to identify four main phases since the 3rd century AD: (1) a fluvial-dominated lagoon between the 2nd–3rd and the 8–9th centuries cal. AD; (2) a gradual desiccation of the lagoon toward a sebkha-like environment from the 9–10th to the 13th centuries cal. AD; (3) a fluvial-dominated lagoon from the 13th century cal. AD; and (4) a second gradual desiccation between the 17th and the 18th centuries cal. AD. The general aridification trend described throughout the study period may be linked to the gradual decline of the Canopic branch, which supplied the Maryut lagoon with freshwater. Nonetheless, at shorter timescales, the different phases of lagoon aridification and flooding coincide with land abandonment and irrigation works in the region. It is suggested that the history of the Alexandria countryside has been a key driver in shaping the environmental history of the Maryut during the past ∼2000 years.     

An Iron Age ceramic sequence from the Bayt Bin Ati,al‐Ain,UAE

Rescue excavations associated with the adaptive reuse of a historic building in the Qattara Oasis revealed a 5 m stratigraphic sequence spanning the past 3000 years. The main period of occupation—roughly half the sequence—belongs to the Iron Age II and III periods (c.1100–300 BC). Evidence of agriculture and industry was found which complements our understanding of the well‐known Iron Age settlements of al‐Ain. The present paper sets out the stratigraphic sequence and presents the phased ceramic assemblage, before considering the broader implications for the archaeology of Iron Age south‐east Arabia.     

«L’europe» 125e congrès national des sociétés historiques et scientifiques université de Lille III 10–15 avril 2000

Vie Scientifique

?L’europe? 125^e congrès national des sociétés historiques et scientifiques université de Lille III 10–15 avril 2000