共查询到20条相似文献，搜索用时 31 毫秒
1.
The effects of climate change during the Terminal Pleistocene–Early Holocene transition on ecosystems and early Prearchaic hunter-gatherers in the central Great Basin of North America are not well understood. We present a palynological reconstruction of regional vegetation and fire history in Grass Valley, central Nevada, from ~14 to ~7.5k cal a BP showing that Pinus-dominated woodlands were replaced by dry-adapted steppe and desert vegetation accompanied by an increase in regional fire activity at the beginning of the Holocene, in response to summer warming and a drying climate. Following a severe drought period peaking ~10.2–9.3k cal a BP, Pinus woodlands partially recovered contemporaneously with the 8.2k cal a BP climate anomaly. Local wetlands provided important resource patches for human foraging societies, and periodic declines of wetlands in response to changing local hydrological conditions may have necessitated adjustments in subsistence and settlement practices and technology. 相似文献
2.
在滦河上游,全新世时期曾有过气候相对湿润阶段,具体表现是:就地起沙的风沙层内,形成了2层特殊的古土壤———黑沙土。黑沙土层分布的厚度不均匀,但具有明显的有机质半固结现象。2层黑沙土之间为黄色风沙层,上层黑沙土又为晚近风沙层覆盖。在下层黑沙土中散布着一些古文化遗存,石片、石核、石斧等石器主要见于下部,陶片数量则以近顶部居多。对黑沙土中的有机质进行14C测年,结果表明,下层黑沙土形成于约7990±150～3200±125aB·P·（cal·）之间,上层黑沙土形成于约3055±170aB·P·（cal·）以后。由这个遗址附近的环境分析证明,古代人类在此活动时期,当地气候处于相对湿润阶段,风沙活动虽依然存在,但可以断定黑沙土的成壤速度大于风沙物质堆积速度,使这里的先民能够依靠农耕、渔猎而生存。大约3200±125aB·P·（cal·）后,风沙堆积速度骤然加快,使黑沙土成土过程一度完全停止,在大约100多年的时间里,风沙活动强烈,形成黑沙土层之间的黄色风沙层堆积。这一时期恶劣的环境使得当时当地的先民无法生存,被迫迁移,从此出现新石器遗址的缺失。该遗址所在的丰宁地区,是影响北京沙尘暴的上源地区之一。因此,该地区环境考古学问题的研究,对了解北京地区沙尘暴变化历史有直接佐证的价值。 相似文献
3.
中晚全新世科尔沁沙地沉积物化学特征及其气候变化 总被引：1，自引：0，他引：1
科尔沁沙地位于我国沙漠-黄土边界带和北方农牧交错带,深受东亚季风的影响,对全球气候变化反应非常敏感,是研究全球气候变化的理想区域。TL剖面磁化率、粒度和地球化学元素氧化物及其比值变化分析表明:中晚全新世研究区气候极不稳定,可以大致划分为:① 6.0～4.2 ka BP,气候暖湿,夏季风逐渐增强,并占据主导,冬季风较弱,与全新世大暖期对应,但存在百年尺度的气候波动,其中:6.0～5.6 ka BP,5.5～5.4 ka BP,4.9～4.7 ka BP,4.5～4.2 ka BP气候暖湿;5.6～5.5 ka BP,5.4～4.9 ka BP,4.7～4.5 ka BP气候相对冷干。② 4.2～1.3 ka BP,气候相对暖湿,与上一阶段相比夏季风有所减弱,其间也存在次一级波动,4.2～3.63 ka BP,3.57～3.4 ka BP气候相对干冷;3.63～3.57 ka BP,3.4～1.3 ka BP,气候相对暖湿。③ 1.3～0.65 ka BP以来,气候波动频繁,后期有向暖湿发展的趋势。这些气候变化与区域和全球变化具有良好的对应关系,反映该区气候变化与全球气候变化具有高度一致性。 相似文献
4.
在14C测年和岩石学的基础上,对豫北平原全新世钻孔沉积物孢粉分析,发现了蒿属、藜科、禾本科、菊科、莎草科、香蒲属6大科属草本,桦属、栎属、榆属3大科属阔叶类,以及裸子植物和蕨类各2种。孢粉含量具有6阶段的组合特征,分别对应6个时期的古气候与古环境演化：10 200~8 200 cal BP,气候冷湿,8 200 cal BP处指示了一次较大的降温事件;8 200~4 000 cal BP,温湿条件有波动,整体上显示了全新世中期整体暖湿气候的特征;4 000~3 300 cal BP,湿度较4 000 cal BP时降低,气候由冷湿向冷干转变;3 300~2 400 cal BP,整体呈寒冷干旱的气候特征;2 400~1 350 cal BP,温度小幅回升,降水增加,气候变暖变湿;1 350 cal BP迄今,温度小幅回落,气候较为干凉。总体上呈“凉湿-暖湿-凉干”的变化特征,各对应时期的裴李岗文化、仰韶文化和龙山文化分别呈现出“欠兴旺-兴旺-衰落”的景象。全新世气候的变化对古文化的兴衰演替有着决定性的影响。温度和湿度升高时期,受水热配置影响,喜湿热动植物增多,植被茂盛,原始农牧业生产力上升,物质相对丰富,人口增加,文化遗址单个规模、密度增大,显示出古文化兴旺的景象;反之,原始农牧业生产力下降,物质相对匮乏,文化遗址单个规模、密度相对变小,显示出古文化衰落的景象。本文研究结果初步表明中原地区中、晚全新世古气候变化与古文化兴衰之间有着很好的耦合关系。 相似文献
5.
A sediment core from Lake BC01 (75°10.945′N, 111°55.181′W, 225 m asl) on south-central Melville Island, NWT, Canada, provides the first continuous postglacial environmental record for the region. Fossil pollen results indicate that the postglacial landscape was dominated by Poaceae and Salix, typical of a High Arctic plant community, whereas the Arctic herb Oxyria underwent a gradual increase during the late Holocene. Pollen-based climate reconstructions suggests the presence of a cold and dry period ~12,000 cal yr BP, possibly representing the Younger Dryas, followed by warmer and wetter conditions from 11,000 to 5000 cal yr BP, likely reflective of the Holocene Thermal Maximum. The climate then underwent a gradual cooling and drying from 5000 cal yr BP to the present, suggesting a late Holocene neoglacial cooling. Diatom preservation was poor prior to 5000 cal yr BP, when conditions were warmest, suggesting that diatom dissolution may in part be climatically controlled. Diatom concentrations were highest ~4500 cal yr BP but then decreased substantially by 3500 cal yr BP and remained low before recovering slightly in the 20th century. An abrupt warming occurred during the past 70 yr at the site, although the magnitude of this warming did not exceed that of the early Holocene. 相似文献
6.
北疆地区早全新世环境演化的湖泊沉积记录 总被引：3，自引：0，他引：3
通过对北疆地区艾比湖沉积物的孢粉组合及其碳酸盐δ^18O,δ^13C,δ^13Corg，TOC，TON和Rb/Sr比等地球化学指标分析，重点对全新世早期气候环境演化特征进行了研究。结果表明，研究时段（8.0-11.cal ka B.P.)温度总体偏低，初期（11.5-10.6cal ka B.P.)较为温湿；早全新世向中全新世转换时期（8.9-8.0cal ka B.P.)气候波动显著。特别是3层泥炭沉积显示了艾比湖地区早全新世气候的强烈不稳定性。泥炭的发育程度及其同位素、孢粉分析数据等都显示，8.2cal ka B.P.,8.6cal ka B.P.,10.5cal ka B.P.的气候状况具有显著的冷湿特征，反映了早全新世的3次冷湿事件。 相似文献
7.
鲁北平原东部巨淀湖处于中国北方季风区,对全球气候变化响应敏感,为研究海岸带地区过去的气候环境演变提供了丰富的湖泊沉积资料。通过对巨淀湖钻孔岩心沉积物孢粉鉴定、粒度分析和AMS14C年代测定,探讨了鲁北平原地区8900 cal a BP以来的气候环境演变过程。结果表明: 8900—7625 cal a BP,气温较高,降水丰沛,气候较暖湿;7625—6810 cal a BP,气候整体呈变凉变干的趋势;6810—4435 cal a BP,温度回升,降水增加,显示了全新世中期整体温暖湿润的气候特征;4435—3150 cal a BP,气候整体寒冷湿润,其间也存在小幅的冷暖波动。中全新世期间5450—5280 cal a BP和4160—4090 cal a BP出现了明显冷干事件,这与中国乃至全球范围内的地质气候记录存在一致性,究其原因可能是受到太阳辐射变化导致的赤道辐合带南移、大洋海表温度变化以及地表植被的反馈作用的共同影响。 相似文献
8.
Holocene environmental evolution recorded by core sediments of Judian Lake in the east of Lubei Plain,Shandong Province 
下载免费PDF全文
下载免费PDF全文 Judian Lake in the east of Lubei Plain is located in the monsoon area of northern China,which is sensitive to global climate change and provides abundant lake sedimentary data for the study of the past climate and environment evolution in the land-sea interaction area. Based on the sporopollen identification,grain size analysis and AMS14C dating of core sediments from the drilling hole of the Judian Lake,the evolutional process of climate and environment since 8900 cal a BP in the northern Lubei Plain was discussed. The results show that: 8900-7625cal a BP,the temperature and precipitation increased and the climate changed from cold-dry to warm-wet;7625—6810 cal a BP,the overall climate was becoming cooler and drier;6810—4435cal a BP,the temperature rose and the precipitation increased,showing an overall warm and humid climate in the middle Holocene;4435—3150cal a BP,the climate was generally cold and humid with some low-amplitude fluctuations of cold and warm. During the middle Holocene,there were two obvious cold and dry events in 5450—5280cal a BP and 4160—4090cal a BP,which was consistent with the geological and climatic records in China and even in the world. It may be due to the southward movement of the equatorial convergence zone caused by the change of solar radiation,the change of ocean surface temperature and the feedback of surface vegetation. 相似文献
9.
10.
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
11.
Holocene pollen and diatom analyses and complementary data from δ18O and δ13C, malacology and sedimentology have provided a detailed record of vegetation history and palaeoenvironmental change at arroyo Las Brusquitas, on the southeastern coast of the pampas of Argentina especially in relation to past sea levels. Holocene palaeosalinity trends were estimated by Detrended Correspondence Analysis and by salinity indexes based on pollen and diatom data. As a consequence of sea‐level rise from the postglacial an extensive wave‐cut platform formed over which Holocene infilling sequences were deposited unconformably. In these sequences, variation in pollen and diatom assemblages occurred in agreement with changes in mollusc diversity and abundance, isotope values, and sediment deposits. Between ca. 6700 and 6190 14C yr BP (6279–6998 cal. yr BP) saline conditions predominated in an environment highly influenced by tides and salt water during the Holocene sea‐level highstand. Between ca. 6200 and 3900 14C yr BP (4235–4608 cal. yr BP) shallow brackish water bodies formed surrounded by saltmarsh vegetation that became more widespread from 5180 14C yr BP (5830–6173 cal. yr BP) to 3900 14C yr BP in relation to a sea‐level stabilisation period within the regression phase. Less saline conditions marked by frequent variations in salinity predominated between ca. 3900 and 2040 yr 14C BP (1830–2160 cal. yr BP). The intertidal saltmarsh environment changed into a brackish marsh dominated by freshwater conditions and sporadic tidal influence. Halophytic vegetation increased towards ca. 200014C yr BP indicating that saline conditions may be due to either desiccation or an unusually high tide range with rare frequency. After ca. 2000 14C yr BP the sedimentary sequences were buried by aeolian sand dunes. Changes in Holocene vegetation and environments in Las Brusquitas area are in agreement with data obtained from various southeastern coastal sites of the Pampa grasslands. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
12.
末次盛冰期以来青藏高原东北部共和盆地气候与环境变化研究进展 总被引：2，自引：1，他引：1
青藏高原东北部共和盆地气候与环境变化文献分析认为:末次盛冰期(14 C年龄14ka BP或16cal ka BP之前)地层沉积主要为风成砂和黄土,冰缘地貌发育,气候寒冷干燥,植被可能为干旱荒漠或荒漠草原;末次冰消期(14 C年龄14ka BP或16 cal ka BP-Younger Dryas,缩写YD事件)地层发育古土壤,湖泊水位明显上升,并显著的捕捉到冷暖事件(Blling-Allerd,缩写B/A、YD)的信息,气候趋于温暖湿润,对应植被为荒漠草原;全新世8.5ka BP(14 C年龄)之前区域温度和湿度不同程度增加,湖泊水位较高,地层发育古土壤,植被为荒漠草原或干草原;8.5～7.0ka BP(14 C年龄)风成砂出现,古土壤发育中断,气候寒冷干燥,为全新世新冰期第一期;7.0～3.0ka BP(14 C年龄)古土壤显著发育,高水位湖面出现,水热组合达到全新世最佳,植被向干草原方向演化,但期间也存在千–百年尺度的冷事件(全新世新冰期第二期);3.0ka BP(14 C年龄)以来气候向温凉(寒冷)干燥方向发展.太阳辐射等外部因素变化并触发地球系统内部各个圈层之间相互作用是区域气候、环境变化的主要驱动力.同时,对研究现状进一步剖析,阐明其存在的问题,并提出气候、环境变化研究的发展方向. 相似文献
13.
Steven N. Bacon Eric V. McDonald Todd G. Caldwell Graham K. Dalldorf 《Quaternary Research》2010,73(3):425-438
The integration of geomorphic mapping, soil stratigraphy, and radiocarbon dating of alluvial deposits offers insight to the timing, magnitude, and paleoclimatic context of Holocene fan sedimentation near Yuma, Arizona. Mapping of 3400 km2 indicates about 10% of the area aggraded in the late Holocene and formed regionally extensive alluvial fan and alluvial plain cut-and-fill terraces. Fan deposits have weakly developed gravelly soils and yielded a date of 3200–2950 cal yr BP from carbonized wood. Alluvial plain deposits have weakly developed buried sandy soils and provided a date of 2460–2300 cal yr BP from a terrestrial snail shell. Precipitation records were analyzed to form historical analogues to the late Holocene aggradation and to consider the role of climatic variability and extreme hydrologic events as drivers of the sedimentation. The historical precipitation record indicates numerous above-average events correlated to the Southern Oscillation Index (SOI) in the region, but lacks any significant reactivation of alluvial fan surfaces. The timing of aggradation from 3200 to 2300 cal yr BP correlates well with other paleoclimatic proxy records in the southwestern U.S. and eastern Pacific region, which indicate an intensification of the El Niño-Southern Oscillation (ENSO) climatic pattern and rapid climate change during this period. 相似文献
14.
The Arctic is more vulnerable to climate change than are mid latitudes. Therefore, palaeolimnological studies from the High Arctic are important in providing insights into the dynamics of the climate system. Here we present a multi‐proxy study from one of the world's northernmost lakes: Bliss Lake, Peary Land, Greenland. The early Holocene (10 850–10 480 cal. a BP) is characterized by increased erosion and gradually more marine conditions. Full marine conditions developed from 10 480 cal. a BP until the lake was isolated at 7220 cal. a BP. From its marine isolation at 7220 cal. a BP Bliss Lake becomes a lacustrine environment. Evidence from geochemical proxies (δ13C and total organic carbon) suggests that warmer conditions prevailed between 7220 and 6500 cal. a BP, corresponding to the Holocene thermal maximum, and from 3300 until 910 cal. a BP. From 850 to 500 cal. a BP colder climate conditions persisted. The transition from warmer to colder climate conditions taking place around 850 cal. a BP may be associated with the transition from the Medieval Warm Period to the Little Ice Age. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
15.
通过对花海古湖泊沉积剖面8.42~0.405 m沉积物样品的矿物和化学元素测定,分析了沉积物中盐类矿物含量及化学元素K/Na比值的变化情况,结合已有的年代地层结果,重建了花海古湖泊10.47~5.5 cal ka BP湖水盐度变化. 结果表明：花海湖泊全新世湖相沉积阶段中,除个别层位以硫酸盐类矿物沉积为主外,早全新世(10.47~8.87 cal ka BP)和中全新世(8.87~5.5 cal ka BP)均以碳酸盐盐类矿物沉积为主,并且早全新世时期K/Na高于中全新世时期,揭示了早全新世时期湖水盐度高于中全新世时期. 这一结果与该湖泊沉积过程所揭示的湖泊水位变化、粒度等揭示的有效湿度变化具有一致性,表明花海湖泊早、中全新世湖水盐度的高低可以指示其湖泊水位的变化,并间接反映了有效湿度的变化. 结合花海湖泊晚全新世湖泊萎缩、气候干旱的特点,该区域早、中、晚全新世气候干湿变化变化模式可以概况为早全新世降水增强、气候呈现由干向湿的转变,中全新世有效湿度最大,晚全新世气候干旱. 这种全新世气候干湿变化模式有别于西风区,亦与季风区不完全相同,呈现出了一种季风-西风过渡带全新世气候干湿变化的模式. 相似文献
16.
头社盆地位于中国台湾省中部，东亚季风区的最前沿，对东亚季风的响应十分敏感，研究其中晚全新世以来古植被、重建古气候序列，探讨其气候与东亚夏季风的关系具有重要的科学意义。文章对头社盆地泥炭—湖泊沉积的AMS14C测年、体积磁化率测试的基础上，基于孢粉记录，重建晚全新世来植被变化，恢复古气候。结果表明全新世中晚期以来分六个阶段：6.2~6.0 cal ka BP，气候凉干，植被类型是亚热带常绿阔叶林；6.0~4.0 cal ka BP，气候转暖湿，植被类型为含较多热带成分的亚热带常绿阔叶林；4.0~2.2 cal ka BP，气候相对凉干，植被类型转为亚热带常绿阔叶林；2.2~1.9 cal ka BP，气候又变暖湿；1.9~1.7 cal ka BP，气候快速冷干事件，森林退化；1.7~1.3 cal ka BP，气候重转温暖湿润，植被类型为接近现代的沼泽草原。整体上6.2~2.2 cal ka BP的气候变化是由温暖湿润向温凉干燥转变的趋势，这是全新世中晚期以来的太阳辐射量减少所导致的，太阳辐射量的减少导致热带辐合南移，进而导致东亚夏季风减弱，而2.2 cal ka BP之后气候波动较大，可能是在东亚夏季风减弱的背景下，ENSO活动加强与人类活动的干扰下耦合的结果。 相似文献
17.
青藏高原东北部泥炭沉积粒度与元素记录的全新世千年尺度的气候变化 总被引：2，自引：0，他引：2
通过对青藏高原东北部共和盆地泥炭沉积的粒度与地球化学元素分析, 重建了区域全新世千年尺度的气候变化过程. 结果显示: 10.0~8.6 cal ka BP区域暖湿程度逐渐增加, 但在8.6~7.1 cal ka BP气候相对寒冷干燥, 7.1~3.8 cal ka BP 暖湿程度总体上为全新世最佳, 但也出现明显的气候波动, 3.8~0.5 cal ka BP气候向冷干方向发展, 0.5 cal ka BP以来气候又逐渐转向暖湿. 这一特征与中国东部季风区的气候变化有很好的一致性. 此外, 区域全新世气候变化过程中存在10次千年尺度的寒冷事件, 并与高原冰芯、 湖泊、 泥炭和风成沉积记录的古气候变化, 甚至与北半球高低纬度的气候变化都具有良好的可比性. 因此, 认为区域全新世气候变化具有"季风模式"与"千年尺度震荡"的双重特点. 相似文献
18.
The early Holocene is characterised by rapid climate change events, which in the North Atlantic region are often associated with changes in thermohaline circulation. Superimposed on this in northwest Europe is localised evidence for human impact on the landscape, although separating climatic and anthropogenic mechanisms for environmental change is often difficult. Biotic and sedimentological evidence from a lacustrine sequence from the Inner Hebrides, Scotland, shows a considerable reduction in inferred local woodland centred upon 8250 cal. yr BP. These data correlate precisely with a distinctive rise in the charcoal:pollen ratio and hence suggest a possible Mesolithic human impact upon the vegetation around this time. A quantitative temperature reconstruction from chironomid analyses from the same sequence, supported by sedimentological data, indicates that the fall in arboreal pollen taxa occurred as climate warmed significantly during the early Holocene. This warming was followed by a significant cold event, with mean July temperatures reduced by 2°C, that lasted for at least 320 years ca. 7790–7470 cal. yr BP. Woodland recovered during this phase suggesting that the vegetation during the 8250 cal. yr BP interval was likely to have been responding to human activity, and not climate, and hence it is possible at specific sites to separate the influence of these key drivers of environmental change. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
19.
Willy Tinner Jacqueline F.N. van Leeuwen Daniele Colombaroli Elisa Vescovi W.O. van der Knaap Paul D. Henne Salvatore Pasta Stefania D'Angelo Tommaso La Mantia 《Quaternary Science Reviews》2009,28(15-16):1498-1510
We used a new sedimentary record to reconstruct the Holocene vegetation and fire history of Gorgo Basso, a coastal lake in south-western Sicily (Italy). Pollen and charcoal data suggest a fire-prone open grassland near the site until ca 10,000 cal yr BP (8050 cal BC), when Pistacia shrubland expanded and fire activity declined, probably in response to increased moisture availability. Evergreen Olea europaea woods expanded ca 8400 to decline abruptly at 8200 cal yr BP, when climatic conditions became drier at other sites in the Mediterranean region. Around 7000 cal yr BP evergreen broadleaved forests (Quercus ilex, Quercus suber and O. europaea) expanded at the cost of open communities. The expansion of evergreen broadleaved forests was associated with a decline of fire and of local Neolithic (Ficus carica–Cerealia based) agriculture that had initiated ca 500 years earlier. Vegetational, fire and land-use changes ca 7000 cal yr BP were probably caused by increased precipitation that resulted from (insolation-forced) weakening of the monsoon and Hadley circulation ca 8000–6000 cal yr BP. Low fire activity and dense coastal evergreen forests persisted until renewed human activity (probably Greek, respectively Roman colonists) disrupted the forest ca 2700 cal yr BP (750 BC) and 2100 cal yr BP (150 BC) to gain open land for agriculture. The intense use of fire for this purpose induced the expansion of open maquis, garrigue, and grassland-prairie environments (with an increasing abundance of the native palm Chamaerops humilis). Prehistoric land-use phases after the Bronze Age seem synchronous with those at other sites in southern and central Europe, possibly as a result of climatic forcing. Considering the response of vegetation to Holocene climatic variability as well as human impact we conclude that under (semi-)natural conditions evergreen broadleaved Q. ilex–O. europaea (s.l.) forests would still dominate near Gorgo Basso. However, forecasted climate change and aridification may lead to a situation similar to that before 7000 cal yr BP and thus trigger a rapid collapse of the few relict evergreen broadleaved woodlands in coastal Sicily and elsewhere in the southern Mediterranean region. 相似文献
20.
河北坝上地区位于东亚季风边缘区和农牧交错带,季风强弱的变化深刻影响着该地区人类文明的发展.为了重建河北坝上地区中-晚全新世以来的气候演化过程,剖析气候变化与人类文明发展的关系,以坝上地区安固里淖湖为研究对象,通过对该湖沉积剖面植硅体的分析,并结合孢粉组合特征,恢复了安固里淖地区5 000 cal.a BP以来的气候演变历史.结果显示,在千年尺度上该区域气候总体呈冷干趋势,但在5 030~3 070 cal.a BP时期气候相对湿润,千年尺度上气候的变化主要受控于北半球太阳辐射量的变化.在百年尺度上安固里淖地区经历了7次冷干事件,分别发生于4 500 cal.a BP、4 100~3 800 cal.a BP、3 500 cal.a BP、3 000 cal.a BP、2 100 cal.a BP、1 100 cal.a BP和800~270 cal.a BP左右,这7次冷干事件对应于东亚季风减弱阶段,主要受到了北半球高纬气候和太阳活动的共同影响.该区人类文明的演化敏感响应于气候变化,气候温湿期以农业文明为主,气候冷干期以草原文明为主. 相似文献