首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   16篇
  免费   0篇
  2020年   1篇
  2017年   1篇
  2015年   1篇
  2013年   1篇
  2012年   2篇
  2011年   3篇
  2010年   2篇
  2008年   2篇
  1995年   1篇
  1994年   2篇
排序方式: 共有16条查询结果,搜索用时 15 毫秒
1.
2.
The presence of many phytolith-rich layers in late Bronze and Iron Age deposits at Tel Dor, Israel, are indicative of specific locations where plants were concentrated. Detailed studies of six of these phytolith-rich layers and associated sediments from Tel Dor show that the phytoliths were derived mainly from wild and domestic grasses. The most common domestic grass was the cereal Triticum aestivum (bread wheat). Three of these layers have a microlaminated microstructure, associated dung spherulites and phosphate nodules; characteristics that all point to the phytolith-rich layers having formed from dung in animal enclosures. In two of the layers, the microlaminated structure is absent while dung spherulites and phosphate nodules are present, suggesting that these too originate from dung that was not deposited in an enclosure. The sixth layer is microlaminated but does not contain spherulites. We thus cannot suggest a parsimonious explanation of its observed properties. Concentrations of burnt phytoliths are present in three locations, implying that dung was either burnt in situ or the ashes from burnt dung were redeposited. The transformation of dung accumulations into phytolith-rich layers involves a loss of organic material and hence a significant reduction in sediment volume, which is clearly apparent in the stratigraphy of some of the locations examined. The volume reduction can be observed in the macrostratigraphy and has important implications with regard to macrostratigraphic interpretation. The presence of abundant phytolith-rich layers on the tell has significant implications for the concept of ‘urbanism’ during these periods.  相似文献   
3.
Esquilleu cave site has provided a moderately well preserved archaeological cave deposit from the Late Pleistocene in the Cantabrian area. Phytolith quantification, identification and determination of the refractive index have been carried out, together with FTIR analyses, from sediment samples collected in the profile. The comparison of the data obtained with the previous micromorphological results allows us to make inferences about the site formation processes and the Neanderthals use of the cave. Phytolith results show the presence of grass leaves nearby the hearth suggesting the repetitive existence of a bedding zone on the same area. Neanderthal behavioral patterns should be revised on the light of high resolution analyses, since diagenetic processes can obscure the existence of differentiated activity areas in the site.  相似文献   
4.
Opaline phytoliths are important microfossils used in archaeological and ecological research. Relatively little is known about the stability of phytoliths after burial. Under alkaline pH conditions they can dissolve, and mechanical disturbances can cause a loss of their more delicate appendages. Here we present an experimental study of phytolith stability (combination of solubility and abrasion). Modern and fossil phytoliths were extracted from wheat using new methods to minimize dissolution, and by burning in an oven. These assemblages were placed in a solution buffered to pH 10 and maintained under constant temperature and shaking conditions. The silicon concentrations in the solution were monitored once a week for 5 weeks. The phytolith morphologies in each assemblage were determined at the outset of the experiment and after 5 weeks. The results show that there are differences in stability between various assemblages. Modern inflorescence wheat phytolith assemblages are more unstable than those from leaves/stems. Burnt assemblages are less stable than unburnt assemblages, and a fossil phytolith assemblage about 3000 years old is more stable than the modern wheat assemblages. The results also show that individual phytolith morphotypes have different stabilities, and as a result of dissolution and abrasion, some morphotypes may resemble others. This study further shows that archaeological and/or paleo-environmental interpretation of phytolith assemblages may change with the assemblage’s state of preservation.  相似文献   
5.
A rapid phytolith extraction procedure is described, that allows phytolith concentrations and morphotype assemblages to be analyzed within hours. This procedure enables the results of these analyses to be used during an archaeological excavation, in order to better understand how plants were used. The new procedure was tested using a standard phytolith extract and two experimental phytolith-sediment blends and found to be both accurate and precise. The reliability of partial slide counting was evaluated and found to be as accurate and precise as existing phytolith quantification methods. The new extraction and counting procedures were applied to an archaeological site, Tell es-Safi/Gath, Israel. The results demonstrate how information on phytolith concentrations in sediments that are available from one day to the next, can be used during an excavation to more effectively document the local features of interest and obtain better information.  相似文献   
6.
7.
Abstract

The study of the technology underlying pre-industrial storage structures has an interest from an anthropological and archaeological perspective, in terms of the evolution of key cultural and cognitive capabilities, often related to the transition to food production.

Microarchaeological techniques offer a unique perspective on the study of pre-industrial storing technologies. In this work, examples are presented from two archaeological contexts in different climatic and socio-ecological situations during the Holocene in S Asia and SW Europe. Microarchaeological techniques used in this study include micromorphology, Fourier transform infrared spectroscopy and phytolith analyses. The comparative study of two pits highlights key aspects of the decision-making process involved in technological solutions of storage: ? The choice of a location for the construction of a given storage facility is highly affected by contextual climatic, microclimatic, soil and bioturbative factors

? The time taken to consume stored foodstuffs seems to affect technological investment as much as the intrinsic conservation requirements of the stored taxa

? The use of fire to hygienise pits implies that such structures were not conceived for single use

? Pre-industrial storage systems can be seen as modular structures, which components (e.g. topographical location, sediment type, lining type, hygienisation techniques and cover) can be recombined to improve storage performance for different climatic settings and foodstuffs.

  相似文献   
8.
During recent years, Spain has experienced an important revolution in its migration flows. With the 2008–2013 Spanish financial crisis, the model of economic growth that attracted a large number of foreign people disappeared, and the entry of immigrants for reasons other than economic issues gained relevance. Linked with this phenomenon are the new patterns of locational choice across provinces and the variation in the nature of immigrants. In this paper, we examine the differential patterns and drivers of immigration across Spanish regions before and after the financial crisis. Special attention is paid to the question of how the characteristics of individual migrants influence their locational preferences. To answer this question, we use the Dirichlet multinomial regression model. The results obtained show a sharp change in the locational patterns of Spanish immigrants after the economic recession, confirming that traditional economic incentives are less relevant, while non-economic factors linked with a better lifestyle gain importance. They also reveal that, regardless of the economic conditions, network effects are strong. Finally, and what is probably more important for us, our estimates support the hypothesis that the locational preferences rely on the interaction between the immigrants’ characteristics and the underlying locational features.  相似文献   
9.
10.
FTIR and phytolith analyses have been used to understand the exceptional preservation of the organic remains at the burial cave of Cova des Pas (Minorca), and to obtain high-resolution data of the plant remains present in the sediments. The presence of sodium nitrate and gypsum suggests a relatively dry environment that has enabled the preservation of the organic material, and contributed to the natural mummification. The dry conditions also favored phytolith preservation. Grass inflorescence phytoliths are abundant all over the site suggesting that phytolith accumulations might have an anthropogenic origin and are related to the burial ritual.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号