首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
Infrared spectroscopy provides information not only on the type of calcium carbonate polymorph, but also on the extent of atomic order. In calcite, three major infrared absorption peaks are identified: ν3, ν2, and ν4. It was shown that the ratio between ν2 and ν4 bands reflects the order of the calcite crystal structure. In this paper we analyse this ratio in geologically formed calcites, archaeological plasters, modern plasters and experimentally prepared plasters. For the geological calcite, the values of the ν2/ν4 ratio are around 3, whereas for the experimentally prepared plasters, the values are around 6.5. The ν2/ν4 ratio for archaeological plasters varies from 3 to 6. This shows that a high ratio is indicative of disorder in the crystal, and implies that the calcite was formed from calcium oxide at high temperatures. It also implies that this disorder can be preserved for at least 14,000 years. The ν2/ν4 ratio of calcite from archaeological sites can thus be used to differentiate between anthropogenic calcite, such as in plaster, mortar and wood ash, from geogenic calcite, such as in limestone. The ratio may also be used to identify plaster or ash that still retains its original crystals and therefore carbon-14 content.  相似文献   

2.
The archaeological record of the Terminal Pleistocene and Early Holocene in the Great Basin consists largely of surface lithic artifacts, and consequently research has concentrated on typological and technological studies. The small suite of radiocarbon dates available suggests human presence in the Great Basin by at least 11,500 B.P., but evidence of subsistence is scanty. Technological analyses as well as artifact distributions suggest that the earliest occupants of this region subsisted primarily by hunting, possibly large terrestrial game. As elsewhere in North America, the earliest occupants of the Great Basin faced a rapidly changing environment, with the drying of shallow pluvial lake remnants and the creation of new habitats. Paralleling these changes, significant subsistence resource diversification coupled with expansion into new environments is evident by the close of the Pleistocene.  相似文献   

3.
Archaeological surface finds are difficult to date. There are several useful methods, but each requires special circumstances and has one drawback or another. On the west coast of South Africa marine shell are abundant on surface sites but they are rarely dated because they are perceived to be in disturbed context and in questionable association with artefacts. This paper attempts to rectify this misconception and shows that, although far from perfect, a large suite of surface dates can shed as much light as excavated data. On the Vredenburg Peninsula they help refute the hypothesis that two economically and culturally distinct populations shared this pre-colonial landscape since 2000 BP.  相似文献   

4.
Caves have yielded some of the most globally important archaeological sequences, but often their interpretation has suffered from assumptions about cave sedimentary processes. Caves contain distinctive sedimentary environments: this has major implications for the understanding of contained archaeological materials. This paper describes and analyses the Holocene sediments in the Haua Fteah, a sequence regarded as essentially continuous by the original excavator. 50 years after it was first excavated, the Haua's Epipalaeolithic to post-Classical chronological range and rich finds make it still the key Holocene archaeological site in North Africa. The reassessment shows, however, that the sequence is strongly discontinuous and this has major implications for the reinterpretation of the site, as the highly-resolved archaeological record is thus likely to reflect a series of brief occupations, rather than continuous human activity. As with many caves, the sedimentary record in the Haua Fteah is an extremely sensitive indicator of environments and processes in the wider landscape. Secure understanding of sedimentary process, from analysis of the highly individual records found in caves, is essential for full understanding of their contained archaeology.  相似文献   

5.
There is an increasing use of palynological data to infer prehistoric agricultural activity. The uncritical acceptance of the technique of pollen analysis by archaeologists and palynologists is questioned. Attention is focussed upon the nature of clearance activity and problems of its inference from pollen spectra; the spatial distribution of palaeoenvironmental sites; and the proximity of such sites to those of prehistoric activity. The resolution apparent in peat and lake sediment pollen profiles together with problems of dating and temporal inference, are examined. In response to a perceived lack of formalization in palynological research, some simple models of clearance activity are presented. The complexity involved in environmental reconstruction is emphasized by reference to the use of supplementary data to augment the orthodox pollen record.  相似文献   

6.
Archaeological evidence regarding the presence of obsidian in levels that antedate the food production stage could have been the result of usage or intrusion of small obsidian artifacts from overlying Neolithic layers. The new obsidian hydration dates presented below employing the novel SIMS-SS method, offers new results of absolute dating concordant with the excavation data. Our contribution sheds new light on the Late Pleistocene/Early Holocene exploitation of obsidian sources on the island of Melos in the Cyclades reporting dates c. 13th millennium - end of 10th millennium B.P.  相似文献   

7.
Archaeological data reveal two distinctive cultural adaptations on the Pampa and Patagonia of Argentina: terrestrial hunter-gatherers in the former and most of the latter region and maritime hunter-gatherers along the southern extreme. Both adaptations were achieved by the end of the fifth millennium B.C. Thereafter, a stable equilibrium was maintained, with a slow drift toward greater emphasis on resources providing the maximum return for the least effort. The high productivity of the Fuegian environment sustained a population 30 times greater than occupied the Pampa and continental Patagonia prior to Araucanian penetration in the sixteenth century A.D. The long-term stability is attributable to the absence of environmental or demographic pressures or encroachments by neighboring groups, which might have made more intensive exploitation of the environment necessary.  相似文献   

8.
Credible interpretation of pollen recovered from archaeological sites hinges upon understanding how pollen becomes deposited by both the environment and human behavior. The environmental role has been studied to some extent, but how the activities of people have formed the pollen assemblages at archaeological sites is usually just assumed rather than considered explicitly. Moreover, the complexity involved in the interaction between human behavior and pollen ecology is seldom considered. An archaeological case study of grinding tool pollen washes highlights the ambiguities of standard practice because the results confound common assumptions about pollen washes. A series of experimental seed and grinding tool washes designed to test the relationships between the processing of seeds and the deposition of pollen help explain why, for most situations, artifact pollen washes do not provide direct or even faithful records of plant processing. These results highlight the need for further experimental research with pollen so that we are warranted in making behavioral inferences from palynology. This conclusion is easily extended to other microbotanical data classes that archaeologists regularly employ.  相似文献   

9.
Abstract

Within the scope of an interdisciplinary research project to determine the genesis and age of small clusters of oak trees, three soil sections in and three outside oak clusters in an ancient woodland/heath on the Veluwe, central Netherlands, were sampled for palynological analysis. The sections within the clusters show an undisturbed development from the Medieval period onwards, the sections outside the clusters are missing ca. 15 cm because of sod cutting associated with plaggen soil formation. The rate of downward movement of pollen was established, using known dates from the near surroundings.  相似文献   

10.
Cryptotephra of Icelandic origin from the open-air archaeological site of Ahrenshöft LA 58 D (Kr. Nordfriesland, Schleswig-Holstein), northern Germany overlies a Late-glacial Havelte lithic assemblage, hitherto dated by 14C and biostratigraphy to the earliest part of the Late-glacial interstadial (GI-1e to GI-1c3). Peaks in ash shards are observed in two profiles. Major and minor element geochemistry indicates volcanic ash originating in the Katla system. Precise correlation to previously described tephra is uncertain due to overlapping chemical characteristics. The Ahrenshöft 14C determinations, litho- and bio-stratigraphy encompass a broad age-span for the cryptotephra bearing sediments, from the end of the Allerød to the Preboreal. The most plausible volcanic eruption correlates are the Vedde Ash (∼Younger Dryas), already known from the European mainland, tephra AF555 (late Younger Dryas) and the Suduroy tephra (∼Preboreal/Boreal), hitherto recorded only in the North Atlantic region. These three ash horizons have been dated to, respectively, 12,171 ± 57 yr b2k in the NGRIP ice-core, c.11,500 cal BP, in Scotland and c.8000 cal BP, by radiocarbon from the Faroe Isles. Ongoing research on deposits from the type sites for the tephra layers may in the future differentiate these markers leading to better discrimination of the chemistries and a resolution of this question.  相似文献   

11.
Archaeopedological analyses in the oasis of Ma'rib (Yemen) yield new information of Neolithic land use, Bronze Age soil formation, and Sabaean irrigation. The AMS radiocarbon age of a Neolithic fireplace buried under Sabaean irrigation sediments in the Southern oasis indicates Pre-Sabaean human activities in Wadi Dhana about 5600 years ago. The associated Mid-Holocene palaeosol, developed in fluvial sediments of Wadi Dhana and also in the filling of the hearth, marks the Bronze Age-land surface before it was covered with irrigation sediments. Based on AMS radiocarbon data from charcoal in reservoir sediments of the “Great Dam” and an estimated time span of pedogenesis of the Mid-Holocene palaeosol in this region, we propose the beginning of the irrigation in Ma'rib in the period of 2500–1000 cal yr BC.  相似文献   

12.
Temporal frequency distributions of archaeological sites and radiocarbon dates are commonly used as proxies for prehistoric population levels based on the assumption that more people create a stronger archaeological signal. While this assumption is certainly correct, we question whether relative frequencies of sites or dates observed from prehistoric contexts are necessarily linked to human demography. In this paper, we demonstrate that the typical positive curvilinear frequency distributions observed in archaeological contexts also regularly occur in paleontological and geological contexts and are thus likely caused by the operation of time-dependent destructive processes, what we call “taphonomic bias.” Using a simple model, which assumes a constant rate of site loss over time, we show how taphonomic bias can produce positive curvilinear frequency distributions through time even in cases of population stasis, decline, and fluctuation. We conclude that caution must be used when attempting to infer demographic trends from frequency distributions alone.  相似文献   

13.
The Longwangchan Paleolithic site, situated on the Yellow River terraces in the Hukou area, Shaanxi province, China, was found in 2003–2004, and two areas (Localities 1 and 2) of the site were excavated in 2005–2008. Abundant stone artifacts including microliths, a grinding stone fragment and a shovel, with some animal bones and shells, were recovered from Locality 1. In this study, the cultural deposits from Locality 1 were dated using radiocarbon and optical dating techniques, and the sediment properties of the deposits were analyzed. The results show that the age of the deposits ranges from 29 to 21 ka and most of them were deposited between 25 ka and 29 ka. This indicates that corresponds to late Marine Isotope Stage (MIS) 3 and early MIS 2. During the human occupation period, the climate in this area became colder and drier. Sediments from beds where the grinding slab and the shovel were found were dated to ∼25 ka, which is the oldest among the grinding stones found in China. The microliths and the grinding stone are important evidence for an incipient socio-economic process that eventually led to the regional transition from hunting-foraging to farming.  相似文献   

14.
Geomorphological and geoarchaeological studies from the lower Gulf region of southeastern Arabia are increasing our knowledge of hydrological, ecological, and aeolian changes during the Holocene. Preliminary analyses of sediment records from two palaeolakes in the United Arab Emirates are presented, highlighting the potential of these sediment sources for providing high-resolution decadal studies of climate change and landscape evolution over the past 10,000 years. In order to study the society-environment relationship in this marginal region, a framework of environmental change is being developed against which the archaeology of the region can be set.  相似文献   

15.
A multi-proxy study (pollen and NPPs, geochemical composition and radiocarbon dating), combined with principal components analysis, was applied to a core sampled in the Monte Areo mire (Asturias, N Spain), which covers the last 11,600 years cal BP. Both signals of Holocene climate change and transformations by human activities were recorded.  相似文献   

16.
The Middle to Upper Paleolithic transition (MP-UP transition) is considered a major technological and cultural threshold, at the time when modern humans spread “out of Africa”, expanded from the Levant into Europe and possibly into central and northern Asia. The dating of this techno-cultural transition has proved to be extremely difficult because it occurred sometime before 40,000 radiocarbon years before present (14C years BP), which is close to the end of the effective dating range of radiocarbon. Other dating methods such as Thermoluminescence (TL) or Electron Spin Resonance (ESR) are not sufficiently precise to date the recorded archaeological MP-UP transition in the Levant. Here we report a consistent set of stratified radiocarbon ages on freshly excavated charcoal from Kebara Cave, Mt. Carmel (Israel), that span the late Middle Paleolithic (MP) and Early Upper Paleolithic (EUP) This study applied novel strategies to improve sample preparation techniques and data analysis to obtain high-resolution radiocarbon models. From this study it is proposed that the MP-UP transition for this site can be placed immediately after 45,200 ± 700 14C years BP and before 43,600 ± 600 14C years BP or from 49/48 to 47/46 radiocarbon calibrated years before present (years Cal BP).  相似文献   

17.
We report an investigation of forty-two prehistoric sites in the upper Yellow River valley located in Guide, Jianzha, Hualong, Xunha and Minhe, Qinghai Province, China, including forty-four new radiocarbon dates from twenty-four sites, review published archaeological surveys and radiocarbon dates, analyze landform features and discuss the reasons for spatial and temporal variety of regional prehistoric human settlement. Our results suggest that people occupied the upper Yellow River valley during the early Holocene, but a continuous archaeological record begins only after about 5500 Cal yr BP. Thereafter, the intensity of prehistoric human settlement in the area is varied. Neolithic human settlement spread northwestward to high altitude areas of the upper Yellow River valley during early-mid Majiayao and Qijia periods, but moved southeastward to lower locations in the area during late Majiayao period. During the Bronze period, two coeval archaeological cultures, the Kayue and Xindian, occupied the upper Yellow River Region. Kayue archaeological sites are numerous and widely distributed in the high areas of the upper Yellow River, while Xindian sites are restricted to the lowest basin of the region. Variation in site density and location are likely the result of changing paleoclimate and technology.  相似文献   

18.
A number of problems associated with the calculation and use of indices for the minimum number of individuals are discussed. Special attention is directed to two of the methods currently in use based on the counting of paired skeletal elements. These methods are described, their ranges of variation determined, and the results of application of each to the same hypothetical faunal sample are described and compared. It is urged that caution be exercised in the application of any of these methods and that the imposition of standardized methods be delayed until a more adequate understanding of the behaviour of even the currently existing measures is available.  相似文献   

19.
Trou de Chaleux and Goyet are caves situated less than 30 km apart in Belgium that contain stratified Magdalenian artefacts and butchered faunal remains. Published radiocarbon dates suggest that both sites were contemporaneously occupied during to the Late-glacial interstadial. It has previously been suggested that the Trou de Chaleux Late-glacial faunal remains might be slightly older than those at Goyet Cave, and that Trou de Chaleux has two phases of occupation during the Late-glacial interstadial. However, the limited number of radiocarbon dates currently available makes it impossible to determine whether the sites are truly contemporaneous, and the assessment of their absolute chronologies is complicated by a plateau in the calibration curve. In this paper, bone collagen δ13C and δ15N signatures of horse bones from the two sites are used to reconstruct local palaeoenvironments. We hypothesise that if occupations at the two sites were contemporaneous, the horse collagen δ13C and δ15N isotope signatures from both sites will be similar, since comparable carbon and nitrogen isotopic values would reflect similar diets, ecologies and environments. To provide clear dating parameters, new AMS radiocarbon determinations are also presented. Results show that horse collagen δ13C and δ15N isotope signatures at the two sites are different, indicating that the populations were not subject to similar diets, ecologies and environments. The new radiocarbon dates confirm that the horse bones from Trou de Chaleux date to the Late-glacial interstadial, but they also show that in Goyet Cave Horizons 1 and 2, older horse remains dating to ca. 32?000–27?000 14C yr BP are mixed with Late-glacial horse remains. The δ15N values of the Goyet Cave horse bones radiocarbon dated to the Pleniglacial are substantially higher than those that have Late-glacial radiocarbon dates. Therefore, we now hypothesise that the majority of the horse bones isotopically analysed from Goyet Cave Horizon 1 are Pleniglacial in age. Statistical analysis of the radiocarbon dates indicates that the Late-glacial occupation at the two sites was contemporaneous, and that while there may appear to be two phases of occupation at Trou de Chaleux, this may be an artefact of the radiocarbon calibration curve.  相似文献   

20.
This paper critically reviews the various approaches used to estimate the age of the rock art in the Kimberley region of Western Australia. They include: (i) the relative superimposition of styles; (ii) the use of diagnostic subject matter (depictions of extinct animals, stone tool technology, introduced European and Asian objects and animals); (iii) the recovery of a ‘painted’ slab from a dated archaeological unit; (iv) radiocarbon dating of beeswax figures, charcoal pigments, organic matter in overlying mineral deposits and ‘accreted paint layers’ (oxalate rich crusts and amorphous silica skin), pollen grains from an overlaying mud-wasp nest; and (v) optically stimulated luminescence (OSL) dating of quartz grains from overlying mud-wasp nests. Future directions for rock art dating in the Kimberley include uranium-series dating of overlying and underlying mineral deposits.  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