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1.
Mörner, N.‐A. and Lind, B., 2011. Reply: Comments on ‘Heimdall's stones at Vitemölla in SE Sweden and the chronology and stratigraphy of the surroundings’ by Mörner et al. (2009). Geografiska Annaler: Series A, Physical Geography, 93, 197–199. DOI: 10.1111/j.1468‐0459.2011.00429.x 相似文献
2.
华南沿海全新世沙坝及其改造利用 总被引：2，自引：0，他引：2
华南沿海沙坝为中、晚全新世形成，分为六个形成期。分析了沙坝的粒度和沉积
寺征及其分布规律。提出华南全新世沙坝的形成与砂源丰富、波浪较强、海平面已与现今相近、
勾造运动相对稳定、季风气候等条件有密切关系。认为沙坝对环境的主要不良影响是：1．产
上风沙灾害；2．烂湾坝阻塞或淤浅航遭。为此提出营造针阔叶混交防风林及配种草本、灌木
向意见。这些沙坝的主要有利因素是：且．含丰富的砂矿：2．形成漏湖式港湾；3．提烘发展农
木牧渔业的广阔空间；咯．可作为建设经济特区。沿海开发区和发展海滨旅游的土地资源。 相似文献
3.
Evolution of sedimentary environments of the middle Jiangsu coast, South Yellow Sea since late MIS 3 总被引：3，自引：0，他引：3
Fei Xia Yongzhan Zhang Qiang Wang Yong Yin Karl W. Wegmann J. Paul Liu 《地理学报(英文版)》2013,23(5):883-914
An evolutionary model of sedimentary environments since late Marine Isotope Stage 3 （late MIS 3, i.e., ca. 39 cal ka BP） along the middle Jiangsu coast is presented based upon a reinterpretation of core 07SR01, new correlations between adjacent published cores, and shallow seismic profiles recovered in the Xiyang tidal channel and adjacent northern sea areas. Geomorphology, sedimentology, radiocarbon dating and seismic and sequence stratigraphy are combined to confirm that environmental changes since late MIS 3 in the study area were controlled primarily by sea-level fluctuations, sediment discharge of paleo-rivers into the South Yellow Sea （SYS）, and minor tectonic subsidence, all of which impacted the progression of regional geomorphic and sedimentary environments （Le., coastal barrier island freshwater lacustrine swamp, river floodplain, coastal marsh, tidal sand ridge, and tidal channel）. This resulted in the formation of a fifth-order sequence stratigraphy, comprised of the parasequence of the late stage of the last interstadial （Para-Sq2）, including the highstand and forced regressive wedge system tracts （HST and FRWST）, and the parasequence of the postglacial period （Para-Sql）, including the transgressive and highstand system tracts （TST and HST）. The tidal sand ridges likely began to develop during the postglacial transgression as sea-level rise covered the middle Jiangsu coast at ca. 9.0 cal ka BP. These initially submerged tidal sand ridges were constantly migrating until the southward migration of the Yellow River mouth to the northern Jiangsu coast during AD 1128 to 1855. The paleo-Xiyang tidal channel that was determined by the paleo-tidal current field and significantly different from the modern one, was in existence during the Holocene transgressive maxima and lasted until AD 1128. Following the capture of the Huaihe River in AD 1128 by the Yellow River, the paleo-Xiyang tidal channel was infilled with a large amount of river-derived sediments from AD 1128 to 1855, causing the emergence of some of the previously submerged tidal sand ridges. From AD 1855 to the present, the infilled paleo-Xiyang tidal channel has undergone scouring, resulting in its modern form. The modern Xiyang tidal channel continues to widen and deepen, due both to strong tidal current scouring and anthropogenic activities. 相似文献
4.
本文是玉门镇西戈壁铁路防沙林带林沿积沙防治试验的总结。研究当地风沙与林沿积沙特征,制定外堵西风口以断沙源、内引东风以退积沙的措施。经过1971—1977年的试验,证实效果良好。 相似文献
5.
ESR能够直接测定第四纪碎屑沉积物年代,尤其是对老于距今20万年以上的沉积物而被广泛应用,但其不很高的测年精度及可重复性不高又限制了其应用的广泛性。野外样品采集及室内分析测试的各个环节都会对ESR测年精度产生影响,因此控制这些环节造成的各种误差是提高ESR测年精度的关键。川西-滇北地区部分河流阶地沉积物ESR年代测定结果与地层层序以及区域地质构造事件基本吻合,表明ESR法测定该区河流阶地沉积物的年代是可行的。在野外采样以及实验室内样品处理测试过程中,采取合理的措施,可以把ESR测年的误差控制在10％～15％的范围内,基本能够满足研究的需要。 相似文献
6.
珠江三角洲新石器考古文化与古地理环境 总被引：12，自引：0，他引：12
珠江三角洲新石器时期的贝丘和沙丘类文化属沿海渔业文化带，其产生和发展与全新的世海面及海陆变迁密切相关。贝丘和沙丘类古文化是随６０００ａＢＰ以前的海侵而产生的；其文化的发展和盛衰过程，在时间和空间上与珠江三角洲海陆环境演变序列都十分吻合。 相似文献
7.
Two adjacent upland floodplains are compared to establish the local response of floodplains to environmental change. Radiocarbon dating, the analysis of sedimentary exposures, terrace mapping, aerial photography and archaeological evidence are used to examine Late Quaternary valley fill sediments on the Afon Tanat and the Afon Vymwy in the Upper Severn Basin, Wales, UK.The alluvial stratigraphy of the two floodplain systems consists of Late Devensian (last glacial) fluvio-glacial sediments at the valley margins deposited under a braided outwash river regime. Holocene age terraces, with floodplain and palaeochannel deposits composed of gravels overlain by silty-sands, are inset into this older unit and were formed by meandering fluvial channel systems. A combination of field and laboratory data demonstrates that from the mid-late Holocene the two floodplain systems had divergent development. The Afon Vyrnwy has remained vertically stable for the last ca. 4000 yrs. whereas the adjacent Afon Tanat continued to be vertically and laterally active.Both floodplain systems have been affected by Late Quaternary climatic fluctuations and anthropogenic activity from the Bronze Age to the Roman period, but local geomorphic gradient controls, combined with a possibly greater focus of anthropogenic activity in the Tanat catchment, may explain the differential evolution of the two systems. The data demonstrate that multiple reach-scale studies are essential for revealing significant stages in the chronology and historical development of fluvial systems. 相似文献
8.
闽粤沿海老红砂的热释光测年 总被引：5，自引：1，他引：4
采用再生热释光法对来自福建和广东沿海地区的39个老红砂样品进行了测年,其年龄约在0.9~6.8万年之间,表明闽粤沿海的老红砂是晚更新世中、晚期形成的风成沉积。 相似文献
9.
Despite the present hyper-aridity, archaeological investigations in South-east Arabia have demonstrated that the region supported extensive human communities throughout the Neolithic and Bronze Age. These early populations utilised the region’s natural environment in a variety of ways, ranging from the exploitation of coastal resources to practicing pastoral and agrarian lifestyles in the interior. Palaeoclimate data suggests the corresponding period was characterised by considerable climatic variability yet, to date, few studies have attempted to investigate the relationship between climate, the environment and early human populations in the region. This paper combines new high-resolution palaeoclimate data from Awafi palaeolake, United Arab Emirates (UAE), with the region’s archaeological record from the Neolithic through to the onset of the Bronze Age. The evidence presented in this paper suggests that the environment of South-east Arabia offered different constraints and opportunities for early human occupation and subsistence. In particular, abrupt phases of aridity are demonstrated to have had a profound impact. Most notable is the change which occurred following the onset of climatic aridity at 5900 cal yr BP, when the region’s semi-nomadic, herder-gatherer populations abandoned much of the landscape and concentrated in selected environmental refugia, such as along the northern Omani coast. Human repopulation during the Bronze Age coincided with a return to more pluvial conditions under which a network of oasis agricultural settlements appeared along the piedmont zone of the northern Hajar Mountains. 相似文献
10.
尾矿砂沙害形成机理与工程治理措施的选择 总被引：1，自引：0，他引：1
尾矿砂沙害的形成过程,包含着尾矿砂强烈风蚀、尾矿砂输送搬运与堆积,以及尾矿砂吹扬在大气中的粉沙悬移等3个过程。上述3个过程对土地、大气、水体、道路、建筑物及农作物造成严重危害,甚至影响人身健康。研究结果表明,尾矿砂的治理,需采用固结沙面、切断沙源,即消除灾害源的方法。固结沙面的材料,宜采用坚固耐久、抗风蚀力强、具有较好蓄水保墒性能,以及保温能力高、且廉价的戈壁沙砾石。沙砾石覆盖之后,不仅固结了沙面,切断了沙源,而且为天然植物种子的散落和幼苗发育创造了稳定条件,加快了天然植物衍生。覆盖后的第一年雨季后,植物盖度到达了15%~30%,局部地段高达50%。 相似文献
11.
Ancient Eskimo dwelling sites and Holocene relative sea-level changes in southern Disko Bugt, central West Greenland 总被引：2，自引：0，他引：2
A coordinated geological-archaeological investigation has been carried out in southern Disko Bugt with the primary purpose of elucidating Holocene relative sea-level (RSL) changes. Two RSL curves representing the Early-Middle Holocene emergence of respectively southeastern and southwestern Disko Bugt have been constructed. Elevations of paleo-Eskimo sites of different ages have been surveyed and supplemented with similar elevations compiled from the literature. Detailed investigations have been carried out at two partly submerged Dorset I sites. At both sites, the stratigraphy of the foreshore has been recorded in terrain profiles.
It is concluded that the RSL history of southern Disko Bugt was one of steady emergence during Early-Middle Holocene followed by submergence in Late Holocene. The stratigraphy of the foreshore at the two Dorset I sites indicates that RSL has been at least 2-2.5 m below sea-level, and that the Transgression to present sea-level started after ca 1 ka B.P. 相似文献
It is concluded that the RSL history of southern Disko Bugt was one of steady emergence during Early-Middle Holocene followed by submergence in Late Holocene. The stratigraphy of the foreshore at the two Dorset I sites indicates that RSL has been at least 2-2.5 m below sea-level, and that the Transgression to present sea-level started after ca 1 ka B.P. 相似文献
12.
太湖地区多剖面地层学分析与良渚期环境事件 总被引：8，自引：2，他引：6
太湖地区多剖面地层学分析和环境考古研究表明:本区良渚期为全新世大暖期中气候逐渐向干凉转变的时期,但大部分时间里仍略比今天暖湿。良渚期末气候走入低谷并剧烈波动,良渚期侵蚀面反映一次较长时间的海面下降过程,气候剧烈波动的转型期与海面下降至低海面过程相一致。此时本区洪积层、埋藏遗址及遗址地层中文化间歇层等发育皆反映古洪水泛滥事件的存在;而良渚期侵蚀面上的铁锰结核聚集现象及现没于水下的众多良渚期开挖的古井等遗迹还反映出这一时期也曾发生过气候干燥事件。分析认为良渚文化繁荣发展期陆地面积扩大,气候略好于今天;而良渚文化衰亡期则处于4300~3800aB. P.间的水、旱灾丛生的低海面气候异常期。 相似文献
13.
N. Tvis Knudsen P. Nørnberg Jacob C. Yde Bent Hasholt Jan Heinemeier 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):137-142
Geografisk Tidsskrift, Danish Journal of Geography 108(1):137–142, 2008 During field observations in August 2005 antler remains of a reindeer were found at a recently deglaciated site at about 500 m asl., and bones from a polar bear were found at about 300 m asl. along the margin of Mittivakkat Glacier, Southeast Greenland. Radio carbon dating determined the age of the samples to 720 14C years and 350 14C years, respectively. In August 2006 old surface vegetation covering peaty material became exposed due to ice recession close to the site where the antler was found. The radio carbon age of small roots from the material was determined to 1530 14C years, and is in agreement with dating of woody remains of Salix glauca found close by, at the top of a nearby nunatak in 1999. The antler indicates that reindeer lived in the area when the glacier began to advance from a position where it was close to or smaller than today. The vegetation surface and peaty material indicate that the climate was warmer before the onset of the Little Ice Age in Southeast Greenland than today. 相似文献
14.
欧亚大陆史前文化交流是当前学术界研究的热点问题,尤其是“一带一路”的国家倡议提出后,青藏高原重要的地理位置确定了其在东西方文化交流中的重要地位。本文基于自然地理因子和不同时期遗址点,在最低成本的控制下实现节点间累积联结的方法,使用GIS（R语言）工具进行空间数值计算,将其结果作为史前时期（新石器—青铜时期)的交流路线。本文重建新石器时期路线27条,总距离约为6000 km;青铜时代30条,总距离约为7800 km。路线的形态由新石器时期的东北—东部—东南—西南边缘呈月牙形环绕发展至青铜时期的由边缘延伸至腹地呈网络化发展的趋势,这是由高原边缘的交流逐步演化成边缘—腹地的交流、并不断强化的表现。重建路线验证了由考古证据支持的农业、驯化动物、彩陶、青铜技术在高原的传播路线,并将其具体化。此外,明确了高原史前交流路线的发展和演变宏观上是受到气候变化的影响,同时受到种植农业技术、驯化动物的传入以及战争等多因素的综合影响。 相似文献
15.
景电二期灌区土地沙漠化特征及治理对策 总被引：2，自引：1，他引：2
景电二期灌区总面积７１１３３ｈｍ２，土地沙漠化和风沙危害是灌区农业发展的主要障碍因子。通过该区土地沙漠化产生的原因、表现形式、以及沙漠化危害综合分析，提出治理和控制沙漠化土地措施有：１）恢复和建立保护性植被体系，２）进一步发展节水灌溉，扩大灌溉面积，３）提高土壤肥力，调整农业生产结构。 相似文献
16.
阿尔泰山古风化壳研究结果表明，晚新生以来，至少存在两个风化期，形成了不同类型的风化壳，本文阐述这两个风化期的特征及相应形成的风化壳的类型及特点。 相似文献
17.
The vegetation on debris flow deposits is examined at seven sites in the Canadian Rocky Mountains. Plant cover, colonizing tree ages, species' presence and abundance, and new stem ages on buried willows are vegetation parameters evaluated for the purpose of dating debris flows. The results indicate that general trends of vegetation development on debris flow deposits can be used to date recent events, at least relatively. The use of several methods to corroborate estimations of deposit age is usually necessary. An optimal approach is to combine absolute and relative dating techniques in evaluating debris flow occurrence, extent, and potential hazard. 相似文献
18.
19.
Kettle ponds in the Cape Cod National Seashore in southeastern Massachusetts differ in their evolution due to depth of the original ice block, the clay content of outwash in their drainage basins, and their siting in relation to geomorphic changes caused by sea-level rise, barrier beach formation, and saltmarsh development. Stratigraphic records of microfossil, carbon isotope, and sediment changes also document late-glacial and Holocene climatic changes.The ponds are separated into 3 groups, each of which follow different development scenarios. Group I ponds date from the late-glacial. They formed in clay-rich outwash, have perched aquifers and continuous lake sediment deposition. The earliest pollen and macrofossil assemblages in Group I pond sediments suggest tundra and spruce-willow parklands before 12 000 yr B.P., boreal forest between 12 000 and 10 500 yr B.P., bog/heath initiation and expansion during the Younger Dryas between 11 000 and 10 000 yr B.P., northern conifer forest between 10 500 and 9500 yr B.P., and establishment of the Cape oak and pitch pine barrens vegetation after 9500 yr B.P. Sedimentation rate changes suggest lowered freshwater levels between 9000 and 5000 yr B.P. caused by decreased precipitation on the Atlantic Coastal Plain. Lake sediment deposition began in the middle Holocene in Group II ponds which formed in clay-poor outwash. These ponds date from about 6000-5000 yr B.P. In these ponds sediment deposition began as sea level rose and the freshwater lens intersected the dry basins. The basal radiocarbon dates of these ponds and stable carbon isotope analyses of the pond sediments suggest a sea-level curve for Cape Cod Bay. Holocene topographic changes in upland and the landscape surrounding the ponds is reconstructed for this coastal area.Group III ponds in the late Holocene landscape of the Provincelands dunes originated as interdunal bogs about 1000 yr B.P. and became ponds more recently as water-levels increased. Peat formation in the Provincelands reflects climatic changes evident on both sides of the Atlantic region.This is the 8th in a series of papers published in this special AMQUA issue. These papers were presented at the 1994 meeting of the American Quaternary Association held 19–22 June, 1994, at the University of Minnesota, Minneapolis, Minnesota, USA. Dr Linda C. K. Shane served as guest editor for these papers. 相似文献
20.
Wisconsin's Central Sand Plain east of the Wisconsin River is composed of eolian sand forming high-relief dunes surrounded by sand sheets and scattered low-relief dunes. To establish a maximum age for dune formation, three samples for optical dating were taken from glacial Lake Wisconsin lacustrine sediment that underlies eolian sand. These age estimates range from 19.3 to 13.6ka. Age estimates taken from within or at the base of the dunes range from 14.0 to 10.6ka. Samples taken from < 2m of the ground surface were slightly younger, indicating dunes were stabilized between 11.8 and 5.5ka. The younger ages near the surface of some dunes were most likely the result of pedoturbation or localized problems with applying the optical dating method. The majority of the optical age estimates from dunes (18 of 21) indicated that most of the dunes were active between 14 and 10ka and that most dune activity ended by 10ka. These ages suggest that localized activity on dune crests may have occurred in the Holocene but would have been limited to < 1m of sand accumulation. The timing of dune activity and the lack of any significant Holocene reactivation suggest that dune activation in this setting cannot be attributed solely to changes in aridity. Instead, we attribute dune formation to changes in sediment availability from either sand inputs from the Wisconsin River or the melting of permafrost. 相似文献