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   20篇
  免费   0篇
  2023年   2篇
  2019年   1篇
  2017年   2篇
  2015年   1篇
  2014年   1篇
  2013年   3篇
  2012年   2篇
  2011年   1篇
  2008年   4篇
  2006年   1篇
  2005年   1篇
  1997年   1篇
排序方式: 共有20条查询结果,搜索用时 15 毫秒
1.
Investigations at the Carson site (22CO505), located in Coahoma County, Mississippi, have uncovered data on the development of a large Mississippian mound center dating to the period from A.D. 1200 through European contact. Recent sediment coring, excavation, artifact analyses, and radiocarbon and optically stimulated luminescence (OSL) dating shed light on earthworks and household structures at Carson, and on Mississippian culture in the Yazoo Basin more generally. Sediment coring demonstrates a laterally transgressing Mississippi River system deposited coarse sandy ridges and clay-filled swales underneath a surface horizon comprised of variously coarse to medium-fine sediment originating from generalized overbank flooding. In some instances, flood-borne sediments were found on mound flanks, indicating that at times river-based flooding may have interrupted mound construction. Sediment coring and trench excavation also demonstrate that Carson’s Mound D was built in four stages, with Stages II and III comprising the major stages of earth moving. Excavations on the mound summit reveal evidence of several superimposed structures that were burned in place and likely used for the production of stone, shell, and wooden craft items, perhaps related to Mississippi Ideational Interaction Sphere (MIIS) paraphernalia. Here we describe recent investigations at Carson and present preliminary findings; forthcoming publications will emphasize strategies of power, monumentality, craft production, and Mississippian exchange systems.  相似文献   
2.
The Iron Age settlements of northern Cameroon were dispersed across the landscape, taking advantage of different eco-climatic zones to exploit a variety of natural resources. Situated at the interface of the upper and lower terraces of the Benue River, mound sites in the area around Garoua have occupation histories spanning multiple centuries. The site of Langui-Tchéboua displays evidence for rapid accumulation of sediments approximately 700 years ago, which may have been a deliberate construction strategy that would have allowed the site’s inhabitants to exploit resources in both floodplain and dryland contexts. The combined use of multiple dating methods and micromorphology provide novel insights into both the mechanisms of anthropogenic landscape change and possible motivations governing those choices.  相似文献   
3.
New work at Kehf el Hammar Cave provides the first well-dated palaeoenvironmental sequence for the Late Upper Palaeolithic in this region of the northwest Maghreb. The archaeological layers are dated via a combination of AMS radiocarbon and luminescence dating methods. The sequence contains charcoal-rich occupation layers with faunal, human and lithic finds. Local vegetational patterns are reconstructed on the basis of preliminary analysis of the charcoal evidence. Using standard calibration curves the AMS radiocarbon dates are compared with proxy evidence for climatic change from sea core records in the Alborán Sea. These appear to show that the Late Upper Palaeolithic occupation of the region coincides closely with Heinrich Event 1, a period marked by intense aridification and dating to ca. 16,700–17,250 calendar years ago.Les nouvelles recherches dans la grotte de Kehf el Hammar ont permis d’obtenir la première séquence paléoenevironnementale bien datée du Paléolithique supérieur tardif au Nord Ouest du Maghreb. En effet, les niveaux archéologiques ont été datés par le radiocarbone par accélérateur (AMS) et des méthodes radiométriques basées sur la luminescence. En revanche, les paléoenvironnements végétaux ont été partiellement reconstitués à base des premières analyses des charbons de bois. Les dates AMS calibrées ont été comparées aux données climatiques issues des carottes marines dans la mer Alborán. Ainsi, les occupations humaines du Paléolithique supérieur tardif dans la région ont sensiblement coïncidé avec l’événement climatique Heinrich 1. Celui-ci correspond à une période qui a été marquée par une aridification intense entre 16.700 et 17.250 ans (cal.).  相似文献   
4.
Optically stimulated luminescence (OSL) dating of heated/fired materials of archaeological importance from various parts of India was attempted. A single-aliquot regenerative-dose (SAR) procedure was used for palaeodose determination in the quartz grains extracted from the heated materials using the luminescence produced by blue light stimulation. In most pottery samples, the palaeodose obtained using SAR-OSL is ∼6% lower than the palaeodose measured using thermoluminescence (TL) method. Broadly, there is good agreement between the SAR-OSL and TL ages of the artefacts and their archaeologically expected ages. The results suggest that routine dating of heated/fired materials using the SAR-OSL procedure is more practicable, especially when the TL sensitivity of the quartz grains is poor and availability of datable material is limited.  相似文献   
5.
Optically stimulated luminescence (OSL) measurements are reported for single grains of quartz from deposits within Sibudu rock shelter. Such measurements enable rejection of unrepresentative grains and application of the finite mixture and central age models to obtain the most reliable age estimates. Three types of single-grain equivalent dose (De) distributions were observed: one sample represented a single dose population, three samples indicated mixing between Iron Age (IA) and Middle Stone Age (MSA) deposits, and 10 samples (in addition to the three mixed samples) showed scattered distributions. The latter type resulted from differences in the beta dose received by individual grains. For these samples, the beta doses were modelled and adjusted accordingly. Ages for the 14 samples collected from MSA deposits post-dating the Howiesons Poort (HP) resulted in three age clusters, which are stratigraphically consistent with the three informally named cultural phases at Sibudu: namely, the post-HP, late MSA and final MSA. Weighted mean ages of 58.5 ± 1.4 ka, 47.7 ± 1.4 ka and 38.6 ± 1.9 ka were calculated for these phases, respectively. The three phases were separated by two occupational hiatuses with durations of 10.8 ± 1.3 ka and 9.1 ± 3.6 ka. We hypothesise that the punctuated presence of humans at Sibudu was determined by large-scale fluctuations in climate during oxygen isotope stage (OIS) 3, which resulted in alternating wet and dry periods. Phases of occupation correspond to wet periods when fresh water was available in the Tongati River, whereas intervals of site abandonment correspond to dry periods when people were forced to migrate in search of a reliable source of fresh water. Where people migrated to, remains unresolved.  相似文献   
6.
Luminescence dating is underutilized in American archaeology given the theoretical advantages of direct dating that it confers. Recent advances in understanding the physical processes underlying the method have also made it more reliable as a dating tool. This research as well as potential applications is reviewed.  相似文献   
7.
This study uses quartz-based optically stimulated luminescence dating to determine when a massive fortification wall (W11186) was constructed in the archaeological site of Tall Zarʿa in the Jordan Valley. A total of 11 samples of sediments were taken from a trench on the north side of the wall (extramuros). The extracted quartz grains had good luminescence characteristics and were identified as well bleached by comparison with feldspar infrared-stimulated luminescence (IRSL) ages. The optical ages showed that the deposition against the wall occurred in two different periods. The first was around 3.20 ± 0.07 ka ago (Iron Age), and the second was around 2.28 ± 0.08 ka (Hellenistic period). Human activity was evident because of the intermixing of cultural material with the presumed naturally deposited units.  相似文献   
8.
Abstract

Dating terraces, the most prominent feature of the agricultural landscape in many parts of the world, is a problem for archaeologists. This study presents an interdisciplinary approach that combines archaeological survey and excavations with direct sediment dating of terrace fill using Optically Stimulated Luminescence (OSL). The study focuses on Ramat Rahel, a multi-period site located in the southern outskirts of modern Jerusalem, Israel, where, on a defined terraced slope chosen for a small-scale landscape archaeology project, three main phases of terrace construction and use were identified. The earliest phase dates to the Late Byzantine/Early Islamic period, the second to medieval times, and the last to the Ottoman period. The results enable a comprehensive reconstruction of the changing local landscape through time and demonstrate the validity of OSL, when combined with archaeological investigations, as a reliable method for terrace dating.  相似文献   
9.
Luminescence dating techniques have been used extensively for archaeological and geological samples. Such techniques are based on thermally or optically stimulated signals. This paper presents simulations of several luminescence techniques for equivalent dose (ED) estimation for ceramic materials containing quartz. The simulations are carried out using a recently published comprehensive kinetic model for quartz, consisting of 11 electron and hole traps and centers. The complete sequence of the experimental protocols for several thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques are simulated using the same set of kinetic parameters. The specific simulated protocols are: additive dose TL protocol, predose technique (both additive and multiple activation versions), phototransfer protocol, single aliquot regenerative optically stimulated luminescence (SAR-OSL) protocol, and SAR thermoluminescence protocol (SAR-TL). One hundred random variants of the natural samples were generated by keeping the transition probabilities between energy levels fixed, while allowing simultaneous random variations of the concentrations of the 11 energy levels. The relative intrinsic accuracy and precision of the protocols are simulated by calculating the equivalent dose (ED) within the model, for a given natural burial dose of the sample. The intrinsic accuracy of these techniques is estimated by simulating natural irradiation of the samples with a known burial dose, followed by simulation of the luminescence method used to recover the estimated dose ED. The percent difference between the burial dose and the ED value represents the simulated accuracy of the luminescence technique. The relative intrinsic precision of these techniques is estimated by fitting Gaussian probability functions to the ED values obtained with the 100 model variants. It is found that the various techniques can reproduce natural paleodoses in the range 10 mGy–10 Gy with a typical intrinsic accuracy of +1 to 10%. Techniques based on single aliquot protocols were found in general to be more precise than techniques requiring the use of multiple aliquots. In addition, techniques based on interpolation of experimental data were found to be consistently both more precise and accurate than those based on extrapolation of experimental data.  相似文献   
10.
Early Himyarite ceramics (first century BC–third century AD) from the Jabal al ‘Awd in Yemen are classified by visual criteria into a number of ware groups. Following classification the ceramics were investigated with petrologic methods (porosity and density). Mineralogical and physical properties were determined from thin sections according to cathodo‐luminescence spectra. The ceramics are divided into six ware groups, each of which has distinctive material properties and mineralogy.  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