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41.
The stability of the Grand Menhir against high velocity winds, and its fall and subsequent breakage are analyzed dynamically. It is concluded that the present locations of the fragments indicate strongly that the menhir was indeed erected and that it broke on impacting with the ground. the Grand Menhir Brisé represents a unique example of breakage in which dynamical principles of solid mechanics have been found scientifically appropriate.  相似文献   
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Summary. Archaeology has long operated from the premise that there was a diverse and ornate organic 'clothing' on the 'dry skeleton' of the past which evades excavation. This paper evaluates the evidence from recent wetlands excavations and considers the implications of the paucity of organic containers found, and the lack of decoration on recovered organic materials, in Britain. It is argued that this negative evidence has important ramifications for our understanding of production and the classification of 'things' in later prehistoric societies. These issues can obviously not be addressed without considering the wealth of organic artifacts recovered at Glastonbury and an extended discussion of its material culture assemblage is included. In conclusion it is stressed that by its relative invisibility 'organic archaeology' has been prone to our normative projections onto the past. The role played by organic goods cannot be understood as being constant and can only be appreciated within their broader archaeological context.  相似文献   
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Our multidisciplinary study of historic Thoroughbred horses solves two long‐running mysteries in racing history. Eclipse, the greatest racehorse ever known, never lost a race. His skeleton is housed in the Royal Veterinary College, London; however, there is controversy over its authenticity. The 1880 Epsom Derby was won by Bend Or. In one of the great controversies of Thoroughbred racing, the owners of Bend Or were accused of swapping him with another horse, Tadcaster, whose maternal pedigree was more prestigious. Bend Or's skeleton resides at the Natural History Museum, in London. Eclipse and Tadcaster were both extremely popular at stud, and the vast majority of racehorses today are descendents. We compared mitochondrial DNA haplotypes of living and historic Thoroughbred skeletons, including those of Eclipse and Bend Or. Additionally, we compared skeletal morphometrics of Eclipse's skeleton with measurements taken at autopsy. Carbon and nitrogen stable isotopes of a range of skeletal elements were compared in order to establish that the Eclipse skeleton was that of a single horse. Our multidisciplinary data suggest that the putative skeleton is consistent with that of Eclipse. In contrast, mitochondrial DNA haplotype sharing indicated that the skeleton known as Bend Or is most probably that of Tadcaster.  相似文献   
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Pollen and macrofossils from an organic deposit probably 44 ka BP in age record subalpine heath with abundant local Athrotaxis cupressoides. This was succeeded by subalpine heath that included Casuarina, Phyllocladus and Eucalyptus. The pollen/vegetation assemblages are comparable with present subalpine vegetation located between 850–1050 m, though the site is at 550 m and potentially below the limit of temperate rainforest (620 m). It is inferred that the vegetation altered from upper to lower subalpine heath and that the climate became warmer and wetter. The mean temperature is estimated to have been at least 3.2°C to 1.7°C colder than today. The trend of vegetation and climate change compares closely with Late Glacial changes but does not compare with changes recorded from sites of Middle Last Glacial age in the West Coast Ranges. A radiocarbon date of 34 ka BP and a trend towards warming suggests that the deposit may represent the onset of an interstadial during the Early Last Glacial Stage.  相似文献   
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Analysis of nitrate transport in the downstream reaches of Duffin Creek, Ontario, revealed an average daily loss of 45 kg nitrate-N during low summer flows. The nitrate loss represents 50 per cent of the average daily input of total nitrogen and 75 per cent of the nitrate input received by these channel reaches. Nitrate uptake by benthic algae appears to account for a small portion of the NO3- removal. Laboratory experiments suggest that most of the nitrate disappearance from the river reaches is caused by bacterial denitrification and nitrate reduction in stream sediments.
L'analyse du transport de nitrate dans l'étendue en aval de Duffin Creek, Ontario, a révélé une perte journalière moyenne de 45 kg de nitrate-N durant l'écoulement affaibli des flots du ruisseau en été. Cette perte de nitrate représente 50 pourcent de la moyenne journalière du total d'azote fourni et 75 pourcent du nitrate reçu par l'étendue de ce canal. Les algues agrostides ne semblent être responsable que d'une faible partie de ladisparition du NO3-. Des experiences en laboratoire suggèrent que presque toute la disparition du nitrate dans la riviere est causée par la dénitrification bactérienne et la réduction d'azote dans les sédiments du cours d'eau.  相似文献   
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This study discusses the relevance of compositions obtained using laser ablation – inductively coupled plasma – mass spectrometry (LA–ICP–MS) for the purpose of identifying the provenance of copper‐based artefacts found in Virginia at Native American sites dated from the 16th to the 18th centuries. Ten artefacts were investigated by scanning electron microscopy – energy dispersive spectrometry (SEM–EDS) to visualize the corrosion and characterize the heterogeneities in the metal and electron probe micro‐analysis (EPMA) to determine separately the compositions of the intact metal and of the corrosion product. It is shown that the corroded surfaces are highly depleted in zinc but that representative concentrations can be determined by sampling the deeper, uncorroded metal. In contrast, lead values are highly variable because of the heterogeneous distribution of this metal within the bulk copper. Despite these problems, brass is easily identifiable and American native copper and European smelted copper can be unambiguously distinguished with LA–ICP–MS on unprepared artefacts using As, Ag, Ni and Sb trace elements.  相似文献   
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