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991.
In prehistory, serpentinite was one of the most frequently used raw materials to produce polished stone artefacts. Several conventional analytical techniques can be applied to identify the serpentine minerals, but their application generally requires a powdered sample. This implies that the artefacts to be analysed must be damaged, and the possibility of analysing a mixture of different serpentine polytypes is high. The use of spatially resolved techniques is therefore a necessity to overcome this problem. Several thin sections of serpentinitic rocks and prehistoric axes have been analysed by synchrotron radiation Fourier transform infrared micro‐spectroscopy. The spectra were acquired directly on specific points of polished stone artefacts and this allowed the recognition of the different polytypes of serpentine minerals without causing any damage to the objects. The results show the infrared micro‐spectroscopy technique to be a useful tool for the characterization of archaeological lithic material.  相似文献   
992.
The present study shows how multivariate analysis and variable selection techniques can be used in archaeological provenances studies to improve classification performances. Neutron activation analysis (NAA), in combination with stepwise linear discrimination analysis (SLDA) (capable of simultaneously performing variable selection and classification), was applied to differentiate among limestone samples from different quarries across the north of France based on their compositional fingerprint. A hierarchical classification approach was followed, aimed at progressively assigning limestone samples to more specific sources of origin, from the broadest classification units (French regions) to the narrowest ones (individual quarries). The application of the stepwise variable selection procedure to extract the most discriminating compositional variables prior to each classification development allowed us to obtain a perfect separation between the limestone categories considered at every classification stage (all samples were correctly classified and predicted in all cases). The high‐quality results obtained were even more remarkable considering the relatively small number of significant variables selected in each case using the SLDA method. An illustrative example was provided in order to demonstrate that the classification strategy proposed can actually allocate an unknown sculpture to a particular quarry of origin.  相似文献   
993.
An illustrated methodology for the morphodynamic sectoring of the Neigette River (Québec) Fluvial hydrogeomorphology is little recognized in policy management and planning in Québec. A better understanding would result in more enlightened planning for waterways. The deficiency could result from the fact that too few methodologies have been developed that take account of the particular nature of Québec rivers. This study tests the applicability of a methodology of dividing rivers into homogeneous morphodynamic units. This compartmentalization results from the analysis of longitudinal changes in stream power, sedimentary composition of the banks, channel entrenchment, and planform geometry. The method is tested on a section of the Neigette River, which encompasses a wide variety of forms and processes frequently found in Québec rivers. Results suggest the presence of three morphodynamic sections: wandering with multiple channels, dynamic meandering and stable meandering. The method provides an effective basis for discriminating between these morphodynamic environments and their respective limits. Stream power is the variable with the greatest discriminating capacity. The efficacy of the approach, the ease of its application, and its flexibility make this a valuable tool for the management of fluvial environments.  相似文献   
994.
The Canadian government and the Meadow Lake Tribal Council sponsored a forest extraction corporation in eastern Nicaragua that restructured 16 Miskitu and Mayangna villages and transformed local human‐environment interactions. The Central American aid project demonstrated paternalistic and interventionist tendencies and exposed biases in inter‐Indigenous aid that rendered it inseparable from conventional aid. This case encourages reflection on social and ecological impacts from the marketing of collective resources, the creation of Indigenous development corporations, and the decision‐making criteria and processes driving foreign aid. The case study demonstrates how foreign aid programs targeting Indigenous Peoples may actually thwart the self‐determination that they set out to encourage. Aid agencies and business partners, who had limited knowledge of local cultures and institutions, created externally defined rules that instigated resource conflicts and undermined the authority of customary leaders without resolving poverty or uneven development.  相似文献   
995.
This article analyzes the mechanisms through which metropolitan governance is established in Montreal's aeronautics sector, one of the most important and innovative industries in the region. The article also examines the role of lead firms, socio‐economic actors, and public agencies from a territorial point of view. It is established that on the one hand the existence of a small number of prime producers at the local level facilitates productive linkages among businesses through subcontracting, and on the other hand, the intensive participation of intermediate socio‐economic agencies and organizations ensures a metropolitan anchoring of the sector and creates a strong territorial identity among the players.  相似文献   
996.
Wetlands are common in Coastal Western Hemlock forests yet the hydrologic processes that generate runoff from small swamps are not completely understood. Direct field observations, hydrologic, and electrical conductivity data were collected from a gently sloping forested swamp complex from July to November 2009. Swamps occupied depressions between raised mounds (0.1 to 3 m high) and were connected by an ephemeral creek. Runoff was controlled by antecedent moisture conditions and influenced by basin microtopography. Two hydrologic regimes occurred during the study period and different runoff processes dominated each regime. Runoff was generated by subsurface flow during dry antecedent conditions as swamps remained hydrologically disconnected from each other. Runoff was generated by surface outflow from hydrologically connected swamps during wet antecedent conditions as ponded water spilled out of the depressions. The forested swamp complex produced a faster but limited hydrologic response during dry antecedent conditions compared to a slower but greater hydrologic response during wet antecedent conditions. Stormwater runoff and runoff ratios were up to two orders of magnitude higher in wet conditions than during similarly sized events in dry conditions. These factors should be considered when designing monitoring programs or runoff models in forested swamps with significant microtopography. Field surveys and estimates of hydrologic inputs and outputs may be useful in predicting the potential hydrologic connectivity of isolated forested swamps.  相似文献   
997.
A palaeoculture sediment profile from the Yuchisi site, Mengcheng County of Anhui Province, China, was sampled to study the concentrations of elements, total carbon content, grain size and pollen percentages, to reveal information on food supply based on statistical analysis of elements between 5050 cal. yr bp and 4000 cal. yr bp . The variations in the reconstructed food supply and pollen percentages are in good agreement with the results of other archaeological methods. The results from pollen and element analyses indicate that the Longshan Culture at the Yuchisi site was not developed from the local Dawenkou Culture, and the cultural transition corresponds with an extremely dry event, which may have caused the change.  相似文献   
998.
999.
1000.
Seasonal patterns of Native American residence and use of shell mounds of the San Francisco Bay area, California are of great interest. This work investigates seasonal occupation by means of a new method for interpretation of geochemical data from Mytilus trossulus specimens recovered from one of these structures, the Ellis Landing Shell Mound (CA-CCO-295). The approach, which is suitable for relatively small shell fragments from a variety of archaeological contexts, is used to infer the environmental conditions (temperature and salinity of ambient water) at harvest time, compared with average conditions for the period, and thus estimate the season during which the shells were harvested. This information, in turn, is employed to evaluate current models about the growth and construction of prehistoric shell mounds in San Francisco Bay. The method was applied to seven different lenses in the shell mound ranging in age from ∼240 cal yr BP to ∼3510 cal yr BP. We found that, although seasonal occupation varied over time, it generally was confined to summer through late fall, with little indication of winter gathering. Our findings suggest that California shell mounds, such as Ellis Landing, were constructed in a very different manner than some other mounded places used by contemporaneous hunter-gatherers elsewhere in North America.  相似文献   
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