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1.
Coastal erosion of sand dune systems along Druridge Bay, northeast England, has progressively exposed parts of the subdune mid‐Holocene landscape, including paleocatenas, indicating former soil hydrosequences with localized wetland habitats, and archaeological evidence of human activities and land use from the Late Mesolithic to the Romano‐British period. Archaeological investigations and pedostratigraphic studies of paleosols provide a unique spatial–chronological framework to interpret soil and land use change over several millennia in the context of a changing coastal environment. Evidence includes dating of archaeological remains, the stratigraphy, morphology and micromorphology of buried soils and sediments, and the palynology and radiocarbon dating of subdune peats. Early Bronze Age burial sites were preferentially located on well‐drained hillocks also used for grazing. Adjacent wetland depressions provided areas of marshy grassland and swamp over deep fen peat soils that started to develop c. 5435 cal. yr B.P. in response to a rising groundwater table stimulated partly by slow sea‐level rise. The backslopes of the paleocatena were occupied by imperfectly to poorly drained soils that supported open oak‐hazel woodland with evidence for progressive clearance and use for agriculture. Windblown sand started to accumulate on the study site sometime between 3930 and 3670 cal. yr B.P., well before the Little Ice Age date for dune formation suggested by previous researchers.  相似文献   

2.
This paper presents the first systematic study of the vegetation history of a range of low hills in SW England, UK, lying between more researched fenlands and uplands. After the palaeoecological sites were located bespoke archaeological, historical and documentary studies of the surrounding landscape were undertaken specifically to inform palynological interpretation at each site. The region has a distinctive archaeology with late Mesolithic tool scatters, some evidence of early Neolithic agriculture, many Bronze Age funerary monuments and Romano‐British iron‐working. Historical studies have suggested that the present landscape pattern is largely early Medieval. However, the pollen evidence suggests a significantly different Holocene vegetation history in comparison with other areas in lowland England, with evidence of incomplete forest clearance in later‐Prehistory (Bronze?Iron Age). Woodland persistence on steep, but poorly drained, slopes, was probably due to the unsuitability of these areas for mixed farming. Instead they may have been under woodland management (e.g. coppicing) associated with the iron‐working industry. Data from two of the sites also suggest that later Iron Age and Romano‐British impact may have been geographically restricted. The documented Medieval land management that maintained the patchwork of small fields, woods and heathlands had its origins in later Prehistory, but there is also evidence of landscape change in the 6th–9th centuries AD. We conclude that the Blackdown Hills area was one of many ‘distinctive subregions’, which due to a combination of edaphic, topographic and cultural factors could qualify as an eco‐cultural region or ‘pays’. It is argued that the use of such eco‐culturally distinctive regions or pays can provide a spatial and archaeological framework for palaeoecology, which has implications for landscape research, designation and heritage management.  相似文献   

3.
Quarry faces several kilometers long in the Glesborg area in Denmark show that Bronze Age farmers used a sustainable land‐use system. Despite nutrient‐poor soils, the Glesborg area was under a rotation system in which cropland alternated with grassland. Soil fertility was improved by the addition of household waste and probably also by locally obtained inorganic fertilizer. The soil surface was very stable, and local drift sand movement was limited. Toward the end of the Bronze Age, the landscape changed dramatically with the arrival of overwhelming amounts of drift sand, and farmsteads were abandoned. Subsequent land use on these poor fine sandy soils was no longer capable of maintaining a stable soil surface, and frequent erosion/sedimentation events of more local importance took place. The post‐Bronze Age landscape may have been mainly a shifting mosaic of heathland with some temporary arable fields and deflation/accumulation areas. This landscape persisted up to about 200 years ago, when afforestation programs started. © 2007 Wiley Periodicals, Inc.  相似文献   

4.
近20年来宜兴市域水稻土有机碳动态及其驱动因素   总被引:29,自引:0,他引:29       下载免费PDF全文
中国农业土壤有机碳的变化一直是国内外农业与全球气候变化研究中十分注意的问题。一些研究提示20世纪末以来我国水稻土尤其是太湖地区水稻土的有机碳储存出现了增长趋势。文章选择了2002年对江苏省宜兴市市域范围水稻土的61个土壤监测点进行系统采样和土壤分析,并与该市分别于1983年和1994年进行的土壤肥力调查结果相对比,从县市区域尺度分析、评价了近20年来太湖地区水稻土表土有机碳储存的变化。尽管20世纪80年代初以前土壤有机碳含量变化以下降为主,但20年来该市域内水稻土有机碳总体上呈上升趋势。统计表明,4个主要土属的表土有机碳密度的增幅以下序递增:湖白土(-2.80tChm2)<白土(10.36tChm2)<乌泥土(13.65tChm2)<黄泥土(14.97tChm2),因而全市74.2×103hm2水稻土表土的总有机碳库从1983年的1.37Tg增加到2002年的2.20Tg。该市水稻土的平均固碳速率达到0.5~0.8tChm2a,这种快速固碳作用与20世纪80年代以来土壤中氮素的富集、秸秆还田的推广和90年代以来该地区不断扩大的冬季休闲有关。目前该市水稻土的固碳潜力仍很大,太湖地区的高产高投入农业不能排除在碳固定上的积极意义。然而,这种快速固碳作用的土壤过程和机理值  相似文献   

5.
The arable soils from two multiperiod settlements were analyzed to identify changes in agricultural methods over time. The settlement middens were also analyzed to determine whether potential fertilizers were discarded unused. Results suggest that in the Neolithic period (˜4000–2000 B.C. in the UK) the arable soils at Tofts Ness, Orkney, and Old Scatness, Shetland, were created by flattening and cultivating the settlements' midden heaps in situ. The arable area at Tofts Ness was expanded in the Bronze Age (˜2000–700 B.C. in the UK), and the new land was improved by the addition of ash, nightsoil, and domestic waste. Cultivation continued briefly after the fields were buried in windblown sand in the Late Bronze Age or Early Iron Age, but by the Early Iron Age cultivation ceased and organic‐rich material was allowed to accumulate within the settlement. By contrast, at Old Scatness, arable production was increased in the Iron Age (˜700 B.C.–A.D. 550 in Scotland) by the intensive use of animal manures. The results indicate that during the lifespan of the two settlements the arable soils were fertilized to increase production, which was intensified over time. © 2006 Wiley Periodicals, Inc.  相似文献   

6.
Soils‐based evidence derived from thin section micromorphology is used to explore contrasts in pre‐Hispanic and Hispanic arable land management practices associated with raised fields in an inter‐Andean valley of Ecuador. Differences in textural pedofeature characteristics suggest that, where they are found in the same locality, camellón systems were more intensively manured and cultivated than wachu systems. Both, however, were more intensively managed than traditional Hispanic arable fields. The importance of the camellón in pre‐Hispanic agriculture is emphasized by soils‐based evidence that highlights the efforts made to clear these fields of volcanic ash after the Quilotoa eruption of ca. A.D. 1280. This research suggests that, in an andosol context, pre‐Hispanic and Hispanic arable land management practices leave relict and fossil soil micromorphology features that can be used to interpret land use intensities. © 2002 Wiley Periodicals, Inc.  相似文献   

7.
稻作和旱作农业的起源与传播一直是植物考古和农业考古研究中的热点,闽江下游地区农业开始的时间及其发展过程对农业向南及向台湾传播的路径和时间研究至关重要,然而由于缺少详细的植物考古学工作,迄今为止关于该地区稻作和旱作农业开始的时间仍然是不清楚的。文章对闽江下游新发掘的闽侯县荆溪镇白头山遗址进行了系统的采样,通过考古学研究和14C测定确立了年代框架,对遗址进行了详细的植硅体分析。研究结果表明,白头山遗址主要包含闽江下游地区新石器时代晚期到末期的遗存(约5000~3000 cal.a B.P.),该遗址中植硅体类型丰富,自昙石山下层文化时期至黄瓜山文化时期,均发现有水稻特征型植硅体,黍子稃壳植硅体首次出现于昙石山文化层,说明在距今5000年左右稻作农业已经传播到了闽江下游,距今4700年左右的昙石山文化时期地层中黍子的出现则说明旱作农业的传入,形成了稻旱混作的原始农业格局。结合闽江流域及台湾地区其他的植物考古学工作,认为闽江是稻旱农业向台湾及东南亚地区传播的重要通道,研究结果为深入了解闽江流域新石器时代农业的发生、发展及其结构特征提供新的认识,为稻旱混作农业南传的时间及路径提供了新的证据。  相似文献   

8.
A systematic archaeoseismological study indicates that at least three earthquakes occurred between 400 B.C. and A.D. 600, causing destruction to numerous ancient monuments in Sicily. Evidence for these earthquakes comes from the collapse style of buildings (toppled walls, column drums in a domino‐style arrangement, directional collapses, etc.), and the exclusion of other likely causes for such effects. Dating of inferred earthquakes is based on coins (accurate to within 5–10 years), pottery (accurate to within 50–200 years), and other artifacts. The oldest documented earthquake occurred between 370 and 300 B.C. and caused the collapse of two Greek temples in Selinunte. This otherwise poorly documented event was probably also the cause of extensive destruction in northeastern Sicily in the first century A.D. Destruction of some sites may be assigned to an earthquake that occurred between 360 and 374 and correlates with the A.D. 365 seismic sequence known from historical sources. This study covers a wider region and provides a more precise dating of earthquakes than previous studies. Although it focuses on a certain period (4th–3rd centuries B.C., 4th–7th centuries A.D.), it indicates that the period before A.D. 1000 is not a period of seismic quiescence in Sicily as was previously believed, but to a period characterized by strong and destructive earthquakes. © 2009 Wiley Periodicals, Inc.  相似文献   

9.
Geoarchaeological work in conjunction with the Kythera Island Project indicates that significant portions of the island are now or have at some time been terraced. Geoarchaeological observations and local historical records confirm extensive terracing during the last few centuries. Detailed stratigraphic, soil, and sediment analysis along with radiocarbon dating suggest, however, that some of the slopes and small drainages of the island were terraced more than once and that this relatively recent phase of terracing followed earlier efforts, some dating to the early second millennium B.C. (Bronze Age). During each phase of slope organization significant amounts of soil were moved locally on the slopes. Polycyclic terracing has, therefore, interesting implications for surface survey visibility, preservation of archaeological record, early agricultural landscapes and soils, and past land use, as well as for interpretation of local records of Holocene sediment mobilization and valley alluviation. Geoarchaeological investigation of terraces may reveal unique archaeological information not available in urban or village dwelling sites. Early features, such as those reported in this paper, however, usually remain hidden due to the remarkable lack of stratigraphic investigations of non‐site landscapes. © 2008 Wiley Periodicals, Inc.  相似文献   

10.
The Sanyangzhuang site, Henan Province, China, has a 12‐m‐deep stratigraphic sequence with remains from the Tang (A.D. 618–907), late Western Han (ca. 140 B.C.–A.D. 23), Warring States (475–221 B.C.), Late Neolithic or Early Bronze Age (ca. 5000–1500 B.C.), Middle Holocene, and Early Holocene times. All of the paleosols are deeply buried. We investigate four issues relevant to the archaeology of the lower Yellow River Valley. First, we confirm that the Yellow River flowed north toward Bohai Bay throughout most of the Holocene. Second, we expand understanding of Holocene paleoenvironments. Long episodes of landscape stability punctuated by brief periods of Yellow River flooding represent the dominant environmental pattern. Third, we investigate how the complex relationships between climate, culture, and the environment affect Yellow River flooding, which in turn shapes Chinese civilization and history. Flooding in late Western Han times affected a vast area of north‐central China; this catastrophe contributed to the downfall of the late Western Han Dynasty. Finally, this research sheds light on the role of Yellow River alluviation in site burial and preservation. Rapid alluviation in the region has buried many archaeological sites. Settlement pattern research needs to take seriously the limitations placed on site visibility in quickly aggrading floodplains. However, gentle alluviation has also preserved settlements and entire landscapes providing unparalleled opportunities to explore the archaeological and historical record of the lower Yellow River Valley.  相似文献   

11.
The soils surrounding three Iron Age settlements on South Mainland, Shetland, were sampled and compared for indicators of soil amendment. Two of the sites (Old Scatness and Jarlshof) were on lower‐lying, better‐drained, sheltered land; the third (Clevigarth) was in an acid, exposed environment at a higher elevation. The hypothesis, based on previous regional assessments, soil thicknesses, and excavations at Old Scatness, was that the lowland sites would have heavily fertilized soils and that the thin upland soil would show little if any amendment. Our findings indicate that the Middle Iron Age soils at Old Scatness had extremely high phosphorus levels, while the soil at Jarlshof had lower levels of enhancement. At Clevigarth, where charcoal from the buried soil was 14C dated to the Neolithic and Bronze Age, there was no evidence of arable activity or soil amendment associated with the Iron Age phases of settlement. These observations indicate that not all sites put the same amount of effort into creating rich arable soils. The three sites had very different agricultural capacities, which suggests the emergence of local trade in agricultural commodities in Iron Age Shetland. © 2008 Wiley Periodicals, Inc.  相似文献   

12.
受历史汞矿开采活动影响,万山汞矿区稻田遭受了严重的汞污染。为了查明万山汞矿区稻田土壤的汞污染现状以及评估其环境质量改善情况,系统采集了受汞矿区影响的五条主干河流沿岸稻田土壤进行汞含量分析,评价总汞和甲基汞污染程度及其生态风险,并与2008年以来该区域稻田土壤汞数据进行对比。结果表明,研究区稻田土壤的总汞含量为0.21~207 mg/kg,几何平均值为(4.26±4.83)mg/kg;甲基汞含量为0.42~13μg/kg,几何平均值为(1.81±1.93)μg/kg。59%的稻田土壤处于重度汞污染,75%的稻田土壤存在极强的汞潜在生态风险。与已往数据相比,稻田土壤汞含量在2012年后呈下降趋势,基本反映了当地汞防治措施的执行效果。为了避免稻田土壤汞污染引起的安全健康风险,今后应采取除污染源治理以外的土壤修复措施或风险管控措施。  相似文献   

13.
Social responses to climate change over human history have been widely discussed in academia over the last two decades. However, the transformation of the human–environment nexus crossing prehistoric and historic periods and the processes associated with it are not yet clearly understood. In this study, based on published works on radiocarbon dating, archaeobotany, zooarchaeology, and archaeological sites, together with a synthesis of historical documents and highresolution paleoclimatic records, we trace the extent to which human settlement patterns in the Hexi Corridor in northwestern China evolved in conjunction with climate change over the last 5,000 years. A total of 129 Neolithic, 126 Bronze Age, and 1,378 historical sites in the Hexi Corridor(n=1,633) were surveyed. Our results show that, in the Late Neolithic and Bronze Age periods(~2800–100 BC), climate change contributed to the transformation of subsistence strategies and the subsequent changes in human settlement patterns in the Hexi Corridor. The warm-humid climate in ~2800–2000 BC promoted millet agriculture and helped the Majiayao, Banshan, and Machang Cultures to flourish. The cold-dry climate in ~2000–100 BC resulted in the divergence and transformation of subsistence strategies in the Xichengyi–Qijia–Siba and Shajing–Shanma Cultures and in a shift in their settlement patterns. However, in the historical period(121 BC–AD 1911), human settlement patterns were primarily determined by geopolitics related to the alternating rule of regimes and frequent wars, especially in the Sui–Tang dynasties. We also find that trans-Eurasian cultural exchange since ~2000 BC improved social resilience to climate change in the Hexi Corridor, mediating the human–environment nexus there. Our findings may provide insights into how human societies reacted to climate change in arid and semi-arid environments over the long term.  相似文献   

14.
The alluvial deposits near Gibala-Tell Tweini provide a unique record of environmental history and food availability estimates covering the Late Bronze Age and the Early Iron Age. The refined pollen-derived climatic proxy suggests that drier climatic conditions occurred in the Mediterranean belt of Syria from the late 13th/early 12th centuries BC to the 9th century BC. This period corresponds with the time frame of the Late Bronze Age collapse and the subsequent Dark Age. The abrupt climate change at the end of the Late Bronze Age caused region-wide crop failures, leading towards socio-economic crises and unsustainability, forcing regional habitat-tracking. Archaeological data show that the first conflagration of Gibala occurred simultaneously with the destruction of the capital city Ugarit currently dated between 1194 and 1175 BC. Gibala redeveloped shortly after this destruction, with large-scale urbanization visible in two main architectural phases during the Early Iron Age I. The later Iron Age I city was destroyed during a second conflagration, which is radiocarbon-dated at circa 2950 cal yr BP. The data from Gibala-Tell Tweini provide evidence in support of the drought hypothesis as a triggering factor behind the Late Bronze Age collapse in the Eastern Mediterranean.  相似文献   

15.
The Holocene sediment of Lago Piccolo di Avigliana (Piedmont, Italy, 356 m a.s.l.) was dated by 14C and analysed for pollen to reconstruct the vegetation history of the area. The early‐ and mid‐Holocene pollen record shows environmental responses to centennial‐scale climatic changes as evidenced by independent palaeoclimatic proxies. When human impact was low or negligible, continental mixed‐oak forests decreased at ca. 9300 BC in response to the early‐Holocene Preboreal climatic oscillation. Abies alba expanded in two phases, probably in response to higher moisture availability at ca. 6000 and ca. 4000 BC , while Fagus expanded later, possibly in response to a climatic change at 3300 BC . During and after the Bronze Age five distinct phases of intensified land use were detected. The near synchroneity with the land‐use phases detected in wetter regions in northern and southern Switzerland points to a common forcing factor in spite of cultural differences. Increasing minerogenic input to the lake since 1000 BC coincided with Late Bronze—Iron Age technical innovations and probably indicate soil erosion as a consequence of deforestation in the lake catchment. The highest values for cultural indicators occurred at 700–450 and at 300–50 BC , coinciding with periods of high solar activity (inferred from Δ14C). This suggests that Iron Age land use was enhanced by high solar activity, while re‐occupation of partly abandoned areas after crises in earlier periods match better with the GRIP stable isotope record. On the basis of our data and comparison with independent palaeoclimatic proxies we suggest that precipitation variation was much more important than temperature oscillations in driving vegetation and societal changes throughout the Holocene. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

16.
The site at Hofstaðir in northeast Iceland has been central to the debate on pre-Christian Norse temples and temple-farm complexes throughout the Scandinavian world. Critical to an understanding of the site have been the various and conflicting interpretations of the great pit feature, which have included the hypotheses that it was intentionally made for the disposal of rubbish after temple feasts, that it was a cooking pit for large-scale food preparation within a temple–farm complex, and that it was the location of a rubbish tip for ordinary farmstead waste materials. In this article we test these competing hypotheses using the technique of thin section micromorphology. These analyses represent the first application of micromorphology to questions of archaeological site formation processes in Iceland, a volcanic island with commonly occurring Andisols. Although this soil type poses new challenges to archaeological soil micromorphology, it was found that pedofeatures, microstructures, and anthropogenic inclusions provide a basis for interpreting site formation processes on Andisols as on other soil types. We conclude that the pit feature had its origins as a sunken-featured building and that the hollow created by the building's abandonment and collapse was later filled with domestic farmstead waste. © 1999 John Wiley & Sons, Inc.  相似文献   

17.
对浙江河姆渡文化田螺山遗址发掘出土的古水稻田沉积有机质开展了详细的有机地球化学分析,从地球化学角度探讨了以田螺山遗址为代表的河姆渡文化稻作农业发展水平以及后期稻田废弃的原因。研究结果揭示,河姆渡文化时期,先民对稻田的开发管理仍处在初级阶段,以原始沼泽型为主。沉积有机质中非挺水水生植物输入指数、平均链长度和藻类输入指数显示,从河姆渡晚期至良渚晚期,田螺山先民耕作区域土壤有机质中藻类等水生生物输入增加,是一个水体逐渐加深的过程,推测生活区周边湖沼环境水体的加深可能是古水稻田废弃的直接原因,甚至有可能是导致整个遗址衰落的直接原因。  相似文献   

18.
Moraine sequences in front of seven relatively low‐altitude glaciers in the Breheimen region of central southern Norway are described and dated using a ‘multi‐proxy’ approach to moraine stratigraphy. Lichenometric dating, based on the Rhizocarpon subgenus, is used to construct a composite moraine chronology, which indicates eight phases of synchronous moraine formation: AD 1793–1799, 1807–1813, 1845–1852, 1859–1862, 1879–1885, 1897–1898, 1906–1908 and 1931–1933. Although the existence of a few cases of older moraines, possibly dating from earlier in the eighteenth or late in the seventeenth centuries cannot be ruled out by lichenometry, Schmidt hammer R‐values from boulders on outermost moraine ridges suggest an absence of Holocene moraines older than the Little Ice Age. Twenty‐three radiocarbon dates from buried soils and peat associated with outermost moraines at three glaciers—Tverreggibreen, Storegrovbreen and Greinbreen—also indicate that the ‘Little Ice Age’ glacier maximum was the Neoglacial maximum at most if not all glaciers. Several maximum age estimates for the Little Ice Age glacier maximum range between the fifteenth and seventeenth centuries, with the youngest from a buried soil being AD 1693. A pre‐Little Ice Age maximum cannot be ruled out at Greinbreen, however, where the age of buried peat suggests the outermost moraine dates from AD 981–1399 (at variance with the lichenometric evidence). Glaciofluvial stratigraphy at Tverreggibreen provides evidence for minor glacier advances about AD 655–963 and AD 1277–1396, respectively. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

19.
The present study examines the geoarchaeological history of an oasis in Kharga Depression in central Egypt. El‐Deir is renowned for its Ptolemaic temple and Roman fortress on the road from former Hibis (Kharga) to the Nile Valley. During the survey, spring mounds and irrigation soils belonging to an ancient agricultural zone were discovered, and further documented by ceramics found on the site. Our methodology combines the geomorphological interpretation of landforms (especially yardangs) with ceramics and 14C‐dated charcoal to distinguish and date former agricultural areas in El‐Deir. The results show that the oasis experienced several phases of soil accretion and destruction through time. Playa sediments were deposited in the humid early Holocene and severely eroded by deflation before the onset of irrigated agriculture between Pharaonic and Persian times. Very fast vertical soil accretion occurred in the Ptolemaic period, but irrigation soils were later destroyed during the Roman period by a combination of wind deflation and flash floods (second to fourth century A.D.), suggesting a period of climate instability. The case of El‐Deir invites reevaluation of constructive agencies for the development of irrigated land and destructive agencies as limiting factors for the sustainability of agricultural practices in late antiquity.  相似文献   

20.
[研究目的]对土壤中硒元素的有效吸收是水稻富硒的关键,而土壤中硒的形态则是影响水稻吸收能力的直接影响因素之一,为了探讨影响富硒土壤中硒的形态与水稻籽实中硒含量的关系,本文对陕西省安康市西部土壤开展了定量研究.[研究方法]本文对研究区土壤硒的形态以及水稻富硒状况进行测定,获得了土壤中各形态硒的赋存状态分布特征.[研究结果...  相似文献   

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