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1.
The elemental geochemical characteristics of Late Quaternary rock core from Yanwo Lake in the Great Wall Station area， King George Island， Southwest Antarctica 
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下载免费PDF全文 ＴｈｅｅｌｅｍｅｎｔａｌｇｅｏｃｈｅｍｉｃａｌｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆＬａｔｅＱｕａｔｅｒｎａｒｙｒｏｃｋｃｏｒｅｆｒｏｍＹａｎｗｏＬａｋｅｉｎｔｈｅＧｒｅａｔＷａｌｌＳｔａｔｉｏｎａｒｅａ，ＫｉｎｇＧｅｏｒｇｅＩｓｌａｎｄ，Ｓｏｕｔｈｗｅ... 相似文献
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《地理学报(英文版)》1997,(4)
ＰｒｏｆｅｓｓｏｒＨｕａｎｇＢｉｎｇｗｅｉｗａｓｂｏｒｎｉｎ1913ｉｎｔｈｅｃｉｔｙｏｆＨｕｉｚｈｏｕ,ＧｕａｎｇｄｏｎｇＰｒｏｖｉｎｃｅ.Ｇｅｏｇｒａｐｈｙｉｓｈｉｓｃｈｏｓｅｎｄｉｓｃｉｐｌｉｎｅ.ＡｆｔｅｒｇｒａｄｕａｔｉｏｎｆｒｏｍｔｈｅＳｕｎＹａｔｓｅｎＵｎｉｖｅｒｓｉｔｙｉｎｔｈｅｓｕｍｍｅｒｏｆ1934,ｈｅｗａｓｇｒａｎｔｅｄａＲｏｃｋｅｆｅｌｌｅｒＦｏｕｎｄａｔｉｏｎｆｅｌｌｏｗｓｈｉｐａｎｄｊｏｉｎｅｄｔｈｅＧｅｏｌｏｇｉｃａｌＳｕｒｖｅｙｏｆＣｈｉｎａｔｏｃａｒｒｙｏｕｔｓｔｕｄｉｅ… 相似文献
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Climatic changes in the regions of Antarctic Great Wall Station,Southern Chile and South Georgia Island 下载免费PDF全文
下载免费PDF全文 ＣｌｉｍａｔｉｃｃｈａｎｇｅｓｉｎｔｈｅｒｅｇｉｏｎｓｏｆＡｎｔａｒｃｔｉｃＧｒｅａｔＷａｌＳｔａ┐ｔｉｏｎ，ＳｏｕｔｈｅｒｎＣｈｉｌｅａｎｄＳｏｕｔｈＧｅｏｒｇｉａＩｓｌａｎｄＺｈａｏＪｕｎｌｉｎ（赵俊琳）ＩｎｓｔｉｔｕｔｅｏｆＥｎｖｉｒｏｎｍｅ... 相似文献
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FAN Jie PANG Xiaomin YANG XiaoguangInstitute of Geography Chinese Academy of Sciences Beijing 《地理学报(英文版)》1998,(2)
ＡｃａｓｅｓｔｕｄｙｏｆＫｏｒｅａ－ｉｎｖｅｓｔｅｄｅｎｔｅｒｐｒｉｓｅｓｉｎＳｈａｎｄｏｎｇＰｅｎｉｎｓｕｌａＦＡＮＪｉｅＰＡＮＧＸｉａｏｍｉｎＹＡＮＧＸｉａｏｇｕａｎｇＩｎｓｔｉｔｕｔｅｏｆＧｅｏｇｒａｐｈｙ,ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳ... 相似文献
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本文材料系南极长城湾ＮＧ９３１柱状样品分析的介形类。共计１１属２１种，其中以Ｌｏｘ－ｏｒｅｔｉｃｕｌａｔｕｍｆａｌａｘ为占最优势组成分子，其次，Ｘｅｓｔｏｌｅｂｅｒｉｓｋｅｒｇｕｅｌｅｎｅｎｓｉｓ，Ｘｅｓｔｏｌｅｂｅｒｉｓｓｐｐ．，Ｓｅｍｉｃｙｔｈｅｒｕｒａｓｐｐ．和Ａｕｓｔｒａｌｉｃｙｔｈｅｒｅｐｏｌｙｌｙｃａ等也为该柱样中介形类的主要组成分子。根据资料分析，ＮＧ９３１柱样中介形类属种绝大部分为南极地区所出现的介形类动物群中的已知类型，它们之间有一定的相似性，推测其生境也有可能相近似。从介形类属种组成上看，应属滨岸－浅海的沉积环境 相似文献
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8.4 ka 以来纳木错湖芯介形类组合的环境变化意义 总被引：1，自引：1，他引：0
对青藏高原中南部纳木错长332cm的NMLC1孔湖芯研究发现,沉积物的介形类动物群计有6属15种。介形类属种生态特征和组合变化分析表明这些介形类对环境条件具有敏感性,其组合能够很好地反映过去环境变化的特征。结果表明,8．4ka以来具有三个不同的环境变化时期：早期在8400～6800aBP,湖泊由浅向深发展,环境具有相对冷湿的特征：中期在6800～2500aBP,湖泊深度逐渐加大,环境经历了暖湿-冷湿-冷干的变化．其中由冷湿向冷干的转化奠定了纳木错现今环境条件的基础：晚期在2500--9aBP,湖泊深度继续增加,这个时期的较早阶段,继续保持了前一时期的冷干特点,但湖水盐度可能开始增加．较晚阶段的冷干化加剧,陆面流水的活跃性大大降低。研究发现,纳木错NMLC1钻孔介形类黑色壳体的高峰值与介形类的最大生产量相一致,并且与沉积水动力条件增强相适应．指示了这些黑壳的产生与介形类的大量繁殖处于同一阶段．并且主要为异地搬运为主。钻孔中出现大量Candona幼虫壳体．其原因可能与沉积环境的水动力条件迅速改变有关。 相似文献
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T.M. Wells A.S. Cohen L.E. Park D.L. Dettman B.A. McKee 《Journal of Paleolimnology》1999,22(3):259-276
We report here on the first detailed ostracode stratigraphic record to be obtained from late Holocene sediments of Lake Tanganyika. We analyzed four cores, three from the northern lake region and a fourth from a more southern lake locality, that collectively record ostracode assemblages under a variety of disturbance regimes. These cores provide a stratigraphic record of ostracode abundance and diversity, as well as depositional changes over time periods of decades to millennia. We have investigated the fossil ostracodes in these cores by looking at temporal changes of species diversity and population structure for the species present. All four cores provided distinct patterns of ostracode diversity and abundance. BUR-1, a northern lake core obtained close to the Ruisizi River delta, yielded a sparse ostracode record. Karonge #3, another northern core from a site that is closely adjacent to a river delta with high sediment loading, yielded almost no ostracodes. The third core 86-DG-14, taken from a somewhat less disturbed area of the lake, suggests that there have been recent changes in ostracode populations. Through most of the lower portion of this core, ostracode abundance is low and species richness is relatively constant. Above 7 cm there is a marked increase in ostracode abundance and a corresponding decrease in species richness, probably signaling the onset of a major community disturbance, perhaps due to human activities. The southernmost core, 86-DG-32, is from a site that is well removed from influent rivers. Ostracode abundance varies erratically throughout the core, whereas species richness is relatively constant and high throughout the core. The temporal variation evident in ostracode community makeup both within and between the studied cores may be a result of naturally patchy distributions among ostracodes, coupled with local extinctions and recolonizations, or it may reflect inadequate sampling of these high diversity assemblages. In either case, these cores illustrate the potential to obtain high resolution ostracode records from the rich, endemic fauna of Lake Tanganyika that can be used to address questions about the history of community structure and human impacts in this lake. 相似文献
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对南极普里兹湾ＮＰ９３－２和ＮＰ９５－１两柱样沉积硅藻进行了定量分析。两柱样分别可划分出３个和７个硅藻组合带。前者的优势种是Ｎｉｔｚｓｃｈｉａｃｕｒｔａ和Ｔｈａｌａｓｉｏｓｉｒａａｎｔａｒｃｔｉｃａ，次优势种是Ｎ．ｋｅｒｇｕｅｌｅｎｓｉｓ和Ｎ．ｒｉｔｓｃｈｅｒｉ；后者常见的优势种有Ｎ．ｋｅｒｇｕｅｌｅｎｓｉｓ，Ｎ．ｃｕｒｔａ，Ｄｅｎｔｉｃｕｌｏｐｓｉｓｓｐｐ．和Ｔ．ｌｅｎｔｉｇｉｎｏｓａ，常见的次优势种有Ｅｕｃａｍｐｉａｂａｂｌａｕｓｔｉｕｍ，Ｔ．ａｎｔａｒｃｔｉｃａ和Ｔ．ｇｒａｃｉｌｉｓ。利用Ｎ．ｃｕｒｔａ／Ｎ．ｋｅｒｇｕｅｌｅｎｓｉｓ比值并结合１４Ｃ测年数据，可将１５０００年以来南极气候的变化划分出８个古气候带，其中完好地记录了Ｈｅｉｎｒｉｃｈ１事件、波令－阿德罗暖期、新仙女木冰期、全新世低温期等重大的气候变化事件，而南极的全新世低温期是首次报道。 相似文献
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Radovan Pipík Anne-Marie Bodergat Danielle Briot Michal Ková? Ján Král’ Grzegorz Zielinski 《Journal of Paleolimnology》2012,47(2):233-249
The Turiec Basin (TB) of Slovakia formed in the Miocene when the West Carpathians escaped from the Alpine region. The 1,250-m-thick
sedimentary Neogene fill of the basin preserved fossil leaves as well as endemic bivalves, gastropods, and ostracodes. The
paleolimnologic changes recorded in the TB infill were derived from the most abundant fossils, the ostracodes. Five contemporaneous
ostracode assemblages within the Late Miocene lacustrine system were distinguished through statistical analysis. These assemblages
have low species similarity, between 2.1 and 24.1%, and are recognized by shape differences among the Candoninae. The ostracode
assemblages, mollusca fossils, and Sr-isotope ratios suggest a low-salinity environment at the beginning of the Late Miocene,
during a brief connection with the Central Paratethys. When the connection ceased, the basin became an isolated freshwater
lake, with five zones differentiated ecologically and bathymetrically using the ostracode assemblages. Taxonomic comparison
of the faunas of the TB and the freshwater to brackish Neogene basins of Europe demonstrates the endemic character of the
TB ostracode fauna. The biologic characteristics of the ostracode families, along with the geology of the lake basin, suggest
that the longevity of the Late Miocene lake probably exceeded 1 Ma. 相似文献
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通过对东南极普里兹湾陆坡区ＮＰ９５－１及西南极长城湾ＮＧ９３－１两柱样系统的环境磁学研究，获得了南极地区１５．０～５．５ｋａＢ．Ｐ．以来的古气候变化序列。结果表明，磁学参数较好地记录了古气候变化及沉积环境变化的信息。ＮＰ９５－１柱样较好地记录了Ｈｅｉｎｒｉｃｈ１事件、新仙女木事件以及波令－阿罗德暖期，其中Ｈｅｉｎｒｉｃｈ１事件发生于１４．３ｋａＢ．Ｐ．，新仙女木冷期为１１．７～１０．３ｋａＢ．Ｐ．，１０．３ｋａＢ．Ｐ．以后，南极地区进入全新世。在全新世，两柱样记录了在１０．０ｋａＢ．Ｐ．及６．０ｋａＢ．Ｐ．前后两个暖期，其间夹有小幅气温下调的时段；６．０ｋａＢ．Ｐ．后，两柱样均有气候颤动变冷的记录。 相似文献
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Vegetation and sedimentation in the Lake Edward Basin, Uganda–Congo during the late Pleistocene and early Holocene 总被引：1，自引：1，他引：0
New palynological and sedimentological data obtained from the basal 3 m of core E96-2P from Lake Edward, Uganda–Congo record conditions wetter than present in the Edward basin from 11 000 to 6700 yr BP, in phase with other climate and vegetation records of northern hemispheric East Africa. Dominant pollen taxa include Celtis spp., Alchornea spp., Olea spp., and Moraceae indicating a moist semi-deciduous tropical forest. More xeric indicators such as Amaranthaceae and Asteraceae together with Poaceae comprise less than 5% of the pollen sum throughout this interval as compared with between 44 and 50% during a lake lowstand at 2000 cal yr BP and at the core top (near modern). The differences between these two assemblages suggest a 25 to 60% increase in annual precipitation during the early- to mid-Holocene as compared to modern (1500–2000 vs. 1200 mm/yr today). Early Holocene sediments in E96-2P are composed of laminated diatom oozes with moderately high total sulfur concentrations (2.8–4.7%) and no authigenic calcite, also indicative of conditions wetter than present. Between 9000 and 6700 yr BP, palynological and sedimentary proxies indicate sub-millennial-scale events related to changes in riverine discharge and runoff in the Edward basin. We attribute the variability in runoff, and hence precipitation, to Holocene variability in Indian or Atlantic Ocean SSTs or to shifts in the relative contribution of Indian and Atlantic moisture sources to the western Rift of equatorial Africa. 相似文献
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Kenji Kashiwaya Toshio Nakamura Nobuki Takamatsu Hideo Sakai Manabu Nakamura Takayoshi Kawai 《Journal of Paleolimnology》1997,18(3):293-297
Physical and chemical properties of two 100 m sediment cores (BDP-93-1, 93-2) obtained from the Buguldeika saddle of Lake Baikal in the eastern Siberia and a 14C-based age scale for the core show that the core bottom is about 400000 years ago and that the changes in the sedimentological environment of the area during the interval were that comparatively coarse and high C/N ratio sediments accumulated in the lake during interglacial periods, and fine material and low C/N ratio during glacial periods. The tentative age scale suggests that the first excursion in the earth's magnetic field at about 26 m (BDP-93-1 and 93-2) from the sediment surface corresponds to the Blake event. Statistical analyses of the data-sets for the some properties show that the fluctuations have distinct periods; 20000 years, 40000 years and 100000 years, that are related to the Milankovitch parameters and support that the tentative age scale is approximately acceptable. 相似文献
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The impact of taphonomic processes on interpreting paleoecologic changes in large lake ecosystems: ostracodes in Lakes Tanganyika and Malawi 总被引：1，自引：0，他引：1
Lisa E. Park Andrew S. Cohen Koen Martens Rebecca Bralek 《Journal of Paleolimnology》2003,30(2):127-138
Nonmarine ostracodes are often used as proxy indicators for the biotic response to climate as well as anthropogenic changes in large lakes. Their large numbers, small size and sensitivities to environmental conditions make them ideal for assessing how organisms respond to environmental perturbations. However, little is known about the various taphonomic processes related to preserving these organisms in the lacustrine fossil record. Without understanding the amount of time averaging associated with these assemblages, any interpretation of their biodiversity and paleoecology may be problematic.To address these issues, we conducted actualistic experiments to determine transport, time-averaging, and the amount of taphonomic bias in ostracode sub-fossil assemblages. Sand transport experiments revealed significant mixing at all sites at shallower depths and significant mixing on rocky substrates but not sandy ones. Comparisons with ostracode material collected along the experimental transects support this model and demonstrate time averaging in both the sandy and rocky substrates. Preservational models were derived from the experimental data and applied to interpreting the paleobiologic record of ostracodes from piston cores in both Lake Tanganyika and Malawi. The core record reveals assemblages that have undergone significant time-averaging, and in the case of Lake Malawi, preservational degradation. In the core examined from Tanganyika, most assemblages resemble the time-averaged experimental model with respect to species richness, percentage of articulated shells and heavy bias towards adult dead individuals. In the Malawi cores, most of the valves were preserved only as internal molds. The taphonomic signature of these samples resemble the time-averaged assemblages of Tanganyika cores, even though carapaces are not often present.Both the experimental and live/dead valve data suggest significant time-averaging and transport, smearing seasonal-yearly data in some environments involved in using ostracodes to assess biotic changes as a result of climate and or anthropogenically-induced environmental change. Ostracode species richness estimates were impacted by time averaging because transport of dead valve material occurs at high percentages in the shallow depths and on the rocky substrates, suggesting that the ostracode death assemblages in these areas will not reflect living populations. In addition, ecologic models based only upon death assemblages will be less resolved than those based upon live assemblages. A time averaging index was derived using the % dead juveniles ratio, as well as sedimentation rate and information on the population dynamics, if known. 相似文献