THE LEAD INGOTS OF CAPO PASSERO: ROMAN GLOBAL MEDITERRANEAN TRADE

Summary.   Epigraphic and isotopic analysis of the lead ingots recovered from a shipwreck off Capo Passero (in Sicily) in mid-2006 suggests that the ingots were produced in Spain, in the Cartagena region. The shipwreck is estimated to have occurred around 38 BC, at the beginning of the Hispanic era. This provides further evidence that the Romans were trading lead throughout the Mediterranean Sea.     

Thermal waters of ‘tectonic origin’: the alkaline,Na‐HCO3 waters of the Rio Valdez geothermal area (Isla Grande de Tierra del Fuego,Argentina)

The geothermal area of Rio Valdez is located in the central portion of the Isla Grande de Tierra del Fuego (South Argentina), ten kilometers south of the southeastern sector of the Fagnano Lake. It consists of a series of thermal springs with low discharge rates (≤1 L/s) and temperatures in the range of 20–33°C distributed in an area of <1 km². The thermal springs are characterized by alkaline, Na‐HCO₃ waters with low salinity (0.53÷0.58 g/L), but relatively high fluoride contents (up to 19.4 mg/L). Their composition is the result of a slow circulation at depth, possibly through deep tectonic discontinuities connected with the Magallanes‐Fagnano Fault (MFF) system. According to geothermometric calculations, thermal waters reach temperatures in the range of 100–150°C and an almost complete chemical equilibrium with the alkali‐feldspars in the metavolcanic country rocks. The relatively high fluorine contents can be explained by the slow ascent and cooling of deep groundwaters followed by a progressive re‐equilibration with F‐bearing, hydrated Mg‐silicates, such as chlorite, which has been recognized as an abundant mineral in the metavolcanics of the Lemaire Formation and metapelites and metagraywackes of the Yahgán Formation. Finally, the isotopic composition of the investigated samples is consistent with the infiltration from local snow melting at altitudes in the range of 610–770 m asl. The comparison of our data with those collected in 1991 seems to suggest a possible progressive decline of the bulk thermal output in the near future. This possibility should be seriously considered before planning a potentially onerous exploitation of the resource. Presently, the only ways to exploit this geothermal resource by the population scattered in the area are the direct use of thermal waters and/or spa structures.     

Functional specialization across space: a case study of the Canadian Electricity Industry, 1971–2001

This article examines the location of functions within the electricity sector in Canada from 1971 to 2001, using a centre‐periphery model. Power generation, distribution and retailing are generally carried out by multiestablishment crown corporations. Location patterns of different functions—management, scientific, production, etc.—are analyzed via the use of occupational groups. The spatial distribution of functions is found to be generally consistent with centre‐periphery relationships, with evidence of a growing functional specialization between large metropolitan and nonmetropolitan locations. However, differences emerge depending on power generation sources: fossil fuels, hydro, nuclear, solar or biomass. The choice of a power generation source has consequences for local economies.     

Coupling Hydrotoponymy and GIS Cartography: A Case Study of Hydrohistorical Issues in Urban Groundwater Systems,Porto, NW Portugal

The aim of this multidisciplinary study is to retrospectively examine hydrohistorical issues, namely hydrogeographic, hydrotoponymical and hydrogeological features, in order to assess the evolution of the Porto urban groundwater system (NW Portugal). To achieve these goals, the comparison of two main field inventories in a large urban region was performed by (i) historical mapping of sources and groundwater data from scientific reports spanning the late 17th century to the early 20th; and (ii) hydrogeologic and hydrotoponymical field inventory performed under current conditions. These field inventories permitted the location of springs, dug wells, fountains, public washing places and underground water galleries, which collected groundwater to supply the population of Porto until the early 20th century. This study also allowed the development of a hydrotoponymical classification for urban areas and a field hydrotoponymical inventory data sheet. This research integrated several techniques based on historical hydrogeography, hydrogeology and urban geosciences. The results of the field inventories were combined into both a database and a Geographical Information System (GIS) platform. This unified methodology allowed a cross‐check and analysis of several levels of information, namely hydrotoponymy, hydroclimatology, hydrogeology, structural geology and geomorphology. This perspective led to an assessment of the evolution of the quality of water resources in large urban areas over time. In addition, the role of hydrotoponymical features is presented in order to support the hydrogeological conceptual model for large urbanised areas.     

Entre intégration économique et cohésion sociale: les coopératives forestières et le développement régional au Québec

Cet article porte sur la relation entre la mondialisation, l'innovation économique et la cohésion sociale au sein des coopératives forestières du Québec dans une perspective de développement régional. Depuis une quinzaine d'années, certaines coopératives forestières au Québec tentent d'innover dans leurs façons de gérer et de produire. Pour innover, ces coopératives s'inscrivent dans un processus de gouvernance avec l'ensemble des acteurs de l'industrie forestière dont l'État, la grande entreprise forestière et les communautés forestières. Cette nouvelle gouvernance semble non seulement permettre aux coopératives forestières d'innover, mais aussi de dynamiser leur capacitéà assurer la cohésion sociale au sein de leurs communautés d'appartenance. La gouvernance forestière apparaît donc comme une stratégie de développement régional pertinente pour les régions qui, comme les régions forestières, sont situées en périphérie et souvent économiquement dévitalisées.     

CHEMICAL AND PHYSICAL CHARACTERIZATION OF STUCCOS FROM A MEXICAN COLONIAL BUILDING: EL MUSEO DEL CALENDARIO OF QUERETARO*

Restoration requires the use of appropriate characterization methods and suitable new material preparation processes permit the reproduction of the original material to be as similar as possible in order to be an appropriate application method. The combination of these factors will facilitate a good restoration process. Different stuccos were taken from El Museo del Calendario, a building located in Querétaro, Mexico which was built in the 16th century. All the stucco samples were studied using the characterization process which is proposed in this article. The characterization method consisted of the use of analytical techniques, such as X‐ray diffraction, Fourier transform infrared and scanning electron microscopy. This characterization method made reproduction of the original material possible. The new material combined with new application techniques developed in situ will result in a high‐quality restoration process.     

Comment expliquer le déclin de Montréal comme centre de transports aériens: une question de géographie économique?

L'objectif de cet article est de comprendre l'évolution des activités aériennes à Montréal. Plaque tournante majeure dans les années 1960, Montréal voit ses activités aériennes ralentir dès le milieu des années 1970. Quelles sont les origines véritables de ce ralentissement? Ce déclin est souvent attribuéà la construction d'un second aéroport international à Montréal‐Mirabel en 1975. Mais qu'en est‐il exactement? Ceci nous amène à nous interroger sur les facteurs de localisation des activités aériennes de manière générale. S'agit‐il d'une activité de service qui se localise selon une logique de places centrales, en fonction de la taille des villes? Faut‐il plutôt chercher ailleurs, par exemple dans les conditions technologiques et réglementaires propres à l'industrie? Pour y répondre, nous proposons une analyse en deux temps. D'abord, nous nous servirons des outils de régression afin d'évaluer l'importance du poids de l'économie locale comme facteur explicatif du trafic aérien. Cette première partie est essentiellement statique. Dans un deuxième temps, nous effectuerons une analyse à caractère davantage historique des activités aériennes de Montréal depuis 1945, pour renouer à la fin avec les résultats de l'analyse de régression.     

CONCEPTUAL DESIGN OF ISOLATION SYSTEMS FOR BRIDGE STRUCTURES

Abstract

In the first part of this paper the objectives of an isolation system for a bridge structure are discussed, in relation to modelling options and modification of the traditional capacity design principles. A displacement-based design approach is then presented, using a linear equivalent single degree-of-freedom model. The preliminary design of an isolation system for existing bridges is based on the definition of a “structure regularity” which allows the estimation of whether the response of the real structure will be similar to that predicted in the preliminary design phase. The efficiency of the approach is shown in designing the isolation system for a highly irregular bridge.