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1.
24 species and 110 506 specimens of mollusks were collected and identified from 250 samples of the loess profile at Madaras, South Hungary. According to changes in the mollusk fauna, six malacological-paleoecological zones can be identified in this profile. The Quaternary malacological data from the Madaras loess section suggest that the Middle and Late Pleniglacial development of the mollusk fauna, and local climatic and environmental conditions in this area differed from other loess regions in Europe.  相似文献   

2.
过去认为涝池河—阳郭动物群的时代相当或稍晚于泥河湾动物群,早于公王岭动物群,厚镇涝池河动物群的时代与公王岭动物群的一致。但各动物群的层位及在动物群演化上所处的位置表明涝池河—阳郭动物群的时代应与公王岭动物群的一致,比泥河湾动物群的晚,而厚镇涝池河动物群的时代应与陈家窝动物群的相当。重新厘定了公王岭期与陈家窝期的涵义,认为蓝田黄土地层中、早更新统的界线应划在Ｓ８与Ｌ９交界处。  相似文献   

3.
内蒙古赤峰西北地区的东村、东梁一带更新世早期河-湖相沉积物相当发育,为一套白色砂与棕红色亚粘土互层,其中含有丰富的哺乳动物化石,计11科18属21种。动物群性质与泥河湾(狭义)的相当。这是我国最东和最北的一个三趾马与真马共生的化石地点。  相似文献   

4.
The loess sequence preserved in the Požarevac brickyard in north-eastern Serbia comprises eight loess units separated by seven paleosols. Geochronological investigation using amino acid racemization and luminescence dating support stratigraphic correlations of loess units L3, S2LL1 and L1 at the Požarevac section with loess of glacial cycles E [Marine Isotope Stage (MIS) 10], D (MIS 9–8), C (MIS 7–6) and B (MIS 5–2) across central Europe. Correlation with the marine oxygen-isotope stratigraphy and associated paleoclimatic inferences are further supported by magnetic susceptibility, particle size and carbonate content measured in Požarevac sediments. Malacological investigations at the Požarevac section reveal the continuous presence of the Chondrula tridens and Helicopsis striata faunal assemblages throughout the last 350 ka. The loess malacological fauna, which is characterized by the complete absence of cold-resistant and cold-preferring species, suggests a stable, dry and relatively warm glacial and interglacial climate, compared with other central European loess localities. Together these data suggest that the south-eastern part of the Carpathian (Pannonian, Middle Danube) Basin was a refugium for warm-preferring and xerophilous land-snails during the generally unfavorable glacial climates of the late Middle and Late Pleistocene.  相似文献   

5.
One hundred and seventeen oriented specimens of loess (in the form of cubes with an edge of 4 cm) were collected from the Wucheng loess section in Xixian County, Shanxi Province. After magnetic cleaning in an alternating field the remanent magnetization of specimens was measured with an astatic magnetometer (sensitivity 4×10?3 emu/cm3). The normally magnetized zone of the Brunhes normal epoch is recorded in upper Pleistocene Malan loess and middle Pleistocene Lishi loess which contain typical Zhoukoudian fauna. The reversely magnetized zone of the Matuyama reversed epoch is observed in lower Pleistocene Wucheng loess, whose fossils are found corresponding to Villafranchian Nihowan fauna.  相似文献   

6.
《Quaternary Science Reviews》2007,26(9-10):1301-1312
The paper focuses on the concept, mapping and discussion of loess distribution in Western, Central and Eastern Europe at a scale of 1:2,500,000. The research work is based on studies and data compilation primarily carried out in the 1970s and 1980s [Fink, J., Haase, G., Ruske, R., 1977. Bemerkungen zur Lößkarte von Europe 1:2,5 Mio. Petermanns Geographische Mitteilungen 2(77), 81–94; Fink, J., 1969 Les progres de l’ etude de loess en Europe. Bulletin de l’ Association française pour l’ etude du Quarternaire 3–12. Haase, G., Ruske, R., Fink, J., 1983. Conception, preparation and some results of the Loess Map of Europe on a scale 1:2,5 Million. INQUA Newsletter 1983(1), 7–10] and completed recently by additional material and literature references. Reference is also made to recent GIS-based data processing and visualisation techniques that were utilised for the final version of the European Loess Map.The paper provides an overview of the history of the conceptualisation of the map as well as on the loess study in Europe, and than considers the cartographic data on loess sediment formation and distribution in Europe. The classification of loess and loess-like sediments and their distribution throughout Europe as reproduced in the map are discussed [Haase, G., Lieberoth, I., Ruske, R., 1970. Sedimente und Paläoböden im Lössgürtel. In: Richter, H., Haase, G., Lieberoth, I., Ruske, R. (Eds.), Periglazial-Löß-Paläolithikum om JUngpleistozän der Deutschen Demokratischen Republik; Petermanns Geographische Mitteilungen 274, 99–212]. The paper illustrates the final state of the loess distribution map of Europe at a scale of 1:2,500,000 and the digital data references on which it is based. Some applications of the map are suggested.  相似文献   

7.
《Quaternary Science Reviews》2003,22(18-19):1835-1857
Upper Pleistocene loess/palaeosol sequences provide excellent high-resolution terrestrial archives of climate forcing. Due to improvements in numerical age determinations, especially in luminescence dating methods, a more reliable time-based reconstruction of the past climate and environmental change has become available for the loess record in Europe. Chronological information was collected from 43 sites along a northwest to southeast transect in Europe. Thirty-three of these sites had sufficient age information to allow estimation of mass accumulation rates, and it was possible to isolate the mass accumulation rates of primary loess during the Last Glacial Period (∼28–13 ka BP) at 21 of these locations. These sites fall along a coarse climatic gradient from the relatively coastal climate of Belgium and France to the drier, more continental climate of Central Europe. Interpreting mass accumulation rates of loess in terms of this climatic gradient is not straightforward as these deposits are dominated by sources in floodplains and large river systems. Thus accumulation rates are influenced strongly by regional wind and precipitation patterns, but mostly by the availability of glacially derived material from the Alps and the periglacial terrains that characterized European fluvial systems during and immediately following glaciation.  相似文献   

8.
本文综述了欧洲白垩纪非海相软体动物群,列出了主要产自英格兰南部、法国和西班牙早白垩世的16个不同沉积层的59个分类单元。淡水动物群以珠蚌类双壳类和田螺类腹足类为主,但在有些地点也存有肺螺类腹足类。这些化石类群与现代类型很相似,说明白垩纪淡水中的水草、氧气与营养环境良好。在欧特里沃期和巴列姆期,淡水与边缘海环境中的动物群组成都发生了显著的变化。欧洲的淡水生物群落早在巴列姆期就已存在,此时的有些类群,如著名的Mar garitifera(s.l.)valdensis在欧洲西部有着广泛的分布。英格兰南部的早白垩世韦尔登群被认为是欧洲最连续的非海相白垩纪地层,其上部的生物群可与西班牙的LasHoyas动物群和法国的Wassy动物群相对比。这3个动物群,以及法国侏罗(汝拉)和英格兰南部波倍克的侏罗纪-白垩纪的过渡生物群——Purbeck动物群,是了解欧洲白垩纪淡水动物群的关键动物群。  相似文献   

9.
Loess was first identified in England as early as the mid-19th century, although these deposits were later mapped as ‘brickearth’ or ‘head-brickearth’ by the British Geological Survey. Much of this material was subsequently recognised and named as loess again by soil scientists, most notably by J.A. Catt. The early reports of loess were mostly located in southeast England, however, more recently loessic deposits have also been reported from the north of England, possibly in Scotland, and as far west as western Ireland. Catt also appreciated that these deposits are the western limits of a broad cover of loess stretching across Eurasia. Here, contrasting models for the possible origin, transport pathways and reworking of these deposits are presented. While some of these British deposits are primary in situ loess, a range of processes has likely affected many of them, including periglaciation, Holocene climatic, and human impacts. Luminescence dating has confirmed British loess to be primarily of late Pleistocene age, however, examples of older loess are also reviewed. Deposits in southeast England are the thickest and best expressed today, and these have yielded significant insight into both the mechanism of the hydroconsolidation (collapse) of loess and landscape evolution in northwest Europe during the Last Glacial Period. The thin and regional nature of British and Irish loess may make it an excellent material for studying loess formation, with advantages over the thicker deposits of typical loess of central Europe, where the impact of smaller scale landscape processes may be less obvious.  相似文献   

10.
The Vyazivok loess sequence from the Dnieper Plain, Ukraine, documents regional environmental changes during the late Pleistocene and Holocene. Pedological and palynological analyses and low-field magnetic susceptibility document changes from dense temperate forest during the last interglacial maximum to open, harsh, loess–steppe during the latest Pleistocene. The Vyazivok section overlies hillwash derived from a lower Pleistocene terrace and consists of two stratified soil complexes (Kaydaky and Pryluky; marine isotope stage [MIS] 5 equivalent) separated by a layer of eolian dust (Tyasmyn silt). The lower soils in both complexes formed within forest. These soils are overlain by the Uday (MIS4) and Bug (MIS2) loess units, which are separated by boreal soils of the Vytachiv (MIS3) complex. The coldest conditions within the record occurred in the youngest loess. Holocene soils cap the Bug loess. The Vyazivok section shows remarkable similarities with other classical loess sequences in western Europe, the Czech Republic, and Austria. The Kaydaky, Pryluky, and Vytachiv deposits, correlate with the PKIII, PKII, and PKI soil complexes, respectively, of the Czech Republic. The Tyasmyn and Prylyky silt layers correspond to marker horizons from central Europe.  相似文献   

11.
Dr. L. Kordos 《GeoJournal》1987,15(2):163-166
Having revised some reference vertebrate faunas from Hungary and from Central Europe their biostratigraphic positions could be determined more accurately. By extending the vole thermometer method to the continental parts of Central Europe fairly well identifiable average July temperature curves could be obtained for the Upper Pleistocene. The main events shown by the climatic curve for Hungary can be well correlated with the soil and loess complexes of the Paks loess profile, and also with the global climatostratigraphic scale.  相似文献   

12.
The azimuth of imbrication of minimum magnetic susceptibility axes in the youngest loess from Ukraine defines prevailing wind directions during aeolian sedimentation. It changes along the studied sections. These changes can be directly correlated with the fluctuations of the Fennoscandian Ice Sheet. The northern and northeastern winds noted in the loess succession separated by a period when southwestern to southeastern winds were predominant may be correlated with two main phases of ice‐sheet advance during the Last Glacial Maximum. The ice‐sheet advances towards the areas of loess deposition generated katabatic winds that influenced aeolian sedimentation in the periglacial zone. A period of relatively stable wind directions during a younger phase of the Last Glacial Maximum was interrupted by periods with more chaotic wind regime most probably caused by fluctuations of the Fennoscandian Ice Sheet during its retreat from the peri‐Baltic part of Europe. These intervals occur where initial soils developed. The distribution of anisotropy of magnetic susceptibility axes defined along the periglacial loess sections from central and eastern Europe can serve to constrain fluctuations of the Fennoscandian Ice Sheet.  相似文献   

13.
Although much emphasis has been placed on the effects of Pleistocene ice sheet as the determinant of Pleistocene climate in Europe, only through the combined evaluation of all useful climatic indicators can Pleistocene climatic zones be differentiated. The relationships between a paleoclimatically determined snowline and polar treelines and extent of loess deposition, determined stratigraphically, botanically, and morphologically, also indicate climatic conditions of Pleistocene Europe. Five great climatic-morphologic and plant-geographic zones, namely, forest-rubble tundra, forest tundra, loess tundra, loess steppe, and loess-forest steppe, may be distinguished. Considering these factors and their characteristics and spatial and temporal extents, it is possible to chronologically present the differentiation of the Würm glacial period independent of the retardation effect of ice sheets. --G. E. Denegar.  相似文献   

14.
In 1985, a programme of research on the sedimentology and diagenesis of the loess and loessic silts of western Europe was initiated jointly by laboratories in Leicester, Meudon, Caen, Milan, Cardiff and Southampton, involving a limited amount of comparative work on the loess from types sites in the Loess Plateau of central China. Preliminary results include the following: (1) Experimental procedures in particle size analysis, clay sample preparation and microscopy have been standardised in all cooperating groups; distinctive fabrics indicative of depositional mechanisms have been recognised. (2) Comparison of aeolian, colluvial and alluvial silt by laser-scanning and bulk magnetic susceptibility anisotropy methods appears to differentiate aeolian silt from loessic silts re-deposited by slope processes and flowing water. (3) The variability in the anisotropy of the limon à doublet facies has been assessed by image analysis of scanning electron microscopy (SEM) and optical microscopy. Strong anisotropy has also been measured in thin section imagery of loess from Normandy and Poland as the product of freezing and thawing. This is confirmed by scanning electron microscopy and by experimental freezing of some silts. (4) The clay fabric and mineralogy in western European loess differ from those in Chinese loess, especially in the case of semi-arid deposits. (5) Distribution of CaCO3, using thin sections and SEM analysis, has been determined for loess from Normandy and the Rhǒne valley in France and for some Chinese loess, At Saint Vallier, zones of CaCO3 concentration occur masking much of the original (loess) sedimentary skeleton which is a locally reworked loessic silt with some laminations. Despite considerable scatter, the palaeomagnetic results indicate a reversed polarity throughout, placing the whole Saint Vallier sequence in the Matuyama chron. These preliminary results suggest the existence of two different palaeoenvironments: one typified by central China, with arid glacials and humid interglacials; and the other represented by western Europe, with generally high humidities. There was stronger weathering and soil development and fewer freezing effects on the lossic succession in northern Italy than in western littoral Europe.  相似文献   

15.
A newly discovered fossil locality at Lano (Basque Country) has yielded a vertebrate assemblage of probably Maastrichtian age comprising fishes, amphibians, reptiles and mammals. It considerably enlarges our knowledge of the Late Cretaceous continental faunas of Europe, hitherto based on a much less complete record. Some taxa are recorded for the first time in Europe, and the fauna also contains the oldest known representatives of some groups (amphisbaenians, salamandrids). The Lan assemblage reveals an original fauna comprising both forms related to Asian and North American groups and elements with Gondwanan affinities.  相似文献   

16.
李希霍芬是19世纪德国著名的地质学家,对欧洲和中国黄土的研究工作,以及后来的黄土研究有着深刻影响,其学术思想在地球系统科学研究的时代依然有重要的现实意义。文章简要回顾了李希霍芬对黄土研究的贡献,并探讨这些贡献与黄土研究在地球系统科学研究中的现实意义。从李希霍芬时代到今天,黄土作为全球宝贵的地球系统演化的历史记录,在揭示地球岩石圈、水圈、大气圈、冰冻圈、生物圈及宇宙事件对地球系统的影响发挥了重要作用,并在未来地球系统科学研究时代有旺盛的生命力。  相似文献   

17.
中国黄土磁性地层与生物地层对比   总被引：2，自引：0，他引：2  
本文统计了中国黄土地层中发现的哺乳动物化石并对一些发现较丰富哺乳动物化石的黄土剖面进行了磁性地层学研究，分析了磁性地层与生物地层对比结果，讨论了黄土层中哺乳动物化石的时空分布，以及有关气候环境问题。  相似文献   

18.
A new feldspar relative TL dating method is proposed that enables dating of pre-Weichselian loess older than 130 ka, by applying the additive γ dose technique and the Mejdahl's exponential extrapolation to alkali feldspar coarse grains. The method is applied to loess deposits from various reference loessic sections of NW Europe. Our relative TL age estimates are consistent with the information provided by the regional stratigraphy; furthermore, they lead to a clear separation of the pre-Weichselian periods of loess deposition in the time period 130 ka–300 ka.  相似文献   

19.
A review of current research on TL dating of loess   总被引：1，自引：0，他引：1  
The thick loess deposits of China, Central Europe and North America are particularly suitable for the application of the thermoluminescence (TL) dating method because individual grains are likely to have travelled large distances and thus been well exposed to light before deposition. Wind-blown silt grains collected close to glacial rivers in Alaska have been shown to give a ‘zero age’ of not more than 2 ka, demonstrating the efficiency of the zeroing mechanism.Differences in laboratory procedures can cause differences in the TL ages reported, particularly for loess over 100 ka. TL ages for interstadial soils in Europe are in agreement with the very few radiocarbon dates on reliable material, such as charcoal. On the other hand TL dates from sites in Belgium and north-western Germany indicate that the previously accepted chronology, which was based on two radiocarbon dates on humic-rich sediments, is incorrect.The use of the ‘last interglacial’ palaeosol for assessing the TL dates on loess above and below it is limited by the uncertainty in the timing of termination of soil-forming processes; 107 and 71 ka are the limits suggested by the astronomically-derived time scale. Results on deposits from China, North America, Alaska and Europe are discussed in this context.  相似文献   

20.
Hafnium (Hf) and zirconium (Zr) concentrations measured in over 4100 agricultural soil samples from Europe were assessed with the focus on their relationship to the distribution of aeolian deposits, such as loess and coversands. Comparison of extractable (aqua regia; ICP‐MS) and total (XRFS) concentrations shows that only 1.0 to 1.7% of the total Hf and Zr is chemically extractable because of the resistant nature of their host minerals. Resistate minerals, such as zircon, are commonly found in the predominantly silty fraction of loess deposits. In this study a statistical analysis of total Hf and Zr soil data from areas with and without loess was carried out to derive threshold values of 10 mg kg?1 (Hf) and 318 mg kg?1 (Zr). These values were subsequently applied across the project area in an attempt to indicate the presence of aeolian deposits. The spatial distribution of above‐threshold concentrations suggests a more extensive and coherent loess belt across central and eastern Europe, providing additional evidence of loess across Brittany, Aquitaine and near the Vosges mountains in France as well as in the basins of central and northern Spain. Above‐threshold concentrations were also detected in loess regardless of its thickness, emphasising the importance of the abundance of zircon in the upper part of the soil profile rather than the actual thickness of the deposit. Soil data however, failed to indicate various loess facies within most of the Pannonian Basin, suggesting that this approach only works where deposits contain a sufficient amount of zircon. This may also explain why the extensive coversands across northern Germany and Poland were largely undetected. This study demonstrates that continental‐scale soil geochemical data can help identify and map the distribution of zircon‐rich loess and coversand, and subsequently enhance and improve current knowledge of the extent of these deposits.  相似文献   

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