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1.
Loess stratigraphy provides the best existing means of establishing an accurate geochronology for the Paleolithic of the Russian Plain, especially for time periods beyond the range of radiocarbon dating. Loess/paleosol sequences in adjoining regions, particularly Central Europe where correlation with oxygen-isotope stratigraphy has been achieved, represent a useful standard for the correlation and dating of loess deposits on the Russian Plain. However, better control is needed over local paleoenvironmental conditions and colluvial redeposition. Correlation is facilitated by two key marker horizons: buried soils of the Last Interglacial (127,000-116,000 B.P.) and the terminal Middle Pleniglacial (30,000-25,000 B.P.); assignment of paleosols and loess beds between these markers to time-stratigraphic units in the Upper Pleistocene sequence is sometimes problematic. Paleolithic remains on the Russian Plain are typically contained in colluvial loam, but can often be related to primary loess stratigraphy. Analysis of the latter suggests sharp contrasts with Western and Central Europe in the timing and distribution of Paleolithic settlement, apparently reflecting the harsher environments of the Russian Plain.  相似文献   

2.
The paper is concerned with problems of the study of Paleolithic sites in the loess regions of the Russian Plain. It is of great significance to correlate prehistorical settlement with Upper Pleistocene cycles of loess and soil formation — not solely in the reconstruction of paleoenvironments. From the cultural layers at various sites paleontological finds and objects were collected for radiocarbon dating. A complex analysis of archeological objects embedded in the loess-paleosol sequence helps us date Upper Pleistocene loess formation cycles. The data acquired from the investigation of the lithological properties of loess and their modification through time and their dependence on relief characteristics permitted a correlation between the various paleoenvironments and the dust accumulation cycles, which played a decisive role in the selection of the most habitable sites.  相似文献   

3.
In 1998, geoarchaeological research was carried out at the Upper Paleolithic site of Studenoe in the Transbaikal Region of Russia. The site is divided into three loci situated on two terraces overlooking the Chikoi River. Alluvial sediments beneath the oldest terrace (T2) consist of two depositional units. Radiocarbon ages indicate that aggradation of the T2 fill began before 18,000 yr B.P. Alluvial sediments beneath the lower terrace (T1) range in age from 13,000 to 10,000 yr B.P. and are divided into three depositional units. Both terraces are overlain by Holocene colluvium. Archaeological materials at Studenoe 1/1, 1/2, and 2 include dwellings, hearths, and thousands of bone and stone artifacts assigned to the late Upper Paleolithic through the Bronze Age. Evidence of microblade technology is present in all components of the site. Material from recent excavations of Paleolithic levels in the T2 fill at Studenoe includes mobiliary art, bone needles, and a large dwelling with four hearth features. © 2003 Wiley Periodicals, Inc.  相似文献   

4.
The thin, loamy brickearth deposits overlying the flinty terrace gravels of the New Forest are divided into older and younger members. The Lower (older) Brickearth includes sediments thought to be mainly loess, with some aeolian sand and possible river floodloam (overbank sediment). These share the common feature of palaeo-argillic soil horizons in their upper layers. Two separate phases of pre-Holocene temperate pedogenesis often can be distinguished in the palaeo-argillic horizons. The Lower Brickearth is the most extensive pre-Devensian loess in Britain. The Upper (younger) Brickearth consists mainly of Late Devensian (Oxygen Isotope Stage 2) loess, but its lower layers also contain fine sand derived mainly from local Tertiary strata. Both brickearths occur on all the terrace surfaces of the New Forest and indicate that the terraces date from Oxygen Isotope Stage 6 or earlier.  相似文献   

5.
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   

6.
In geoarchaeological studies, there is an issue with distinguishing between natural and anthropogenic signals in pedological paleoarchives. With the pedostratigraphy of the Upper Paleolithic site of Kostenki 14, this issue is reflected by problems with the determination of features of pedogenic and pyrogenic processes. This issue was addressed by means of a thorough analysis of the magnetic properties of paleosols accompanied by micromorphological observations. Most of the humic samples were shown to be a result of pedogenesis, but two samples (a Paleolithic hearth sample and a sample from paleosol IIc) had features of intensely burnt material. The difference in the typical intensity of large-scale (natural or human-induced) and local-scale anthropogenic fire allowed for suggesting that the magnetic properties of the burnt sample were the result of an anthropogenically controlled fire event, that is, a hearth. This study shows that the magnetic properties of paleosols can be used to differentiate anthropogenic activity, in particular—burning, from pedogenic processes. This indicator is especially helpful in finding disturbed combustion features when the hearth structure is lost. This methodology used to demonstrate the local human-induced pyrogenic effect at the Upper Paleolithic site can contribute to the discussion of the niche construction effect of human activities in the Pleistocene.  相似文献   

7.
The Dawson Cut Forest Bed lies in the lower part of thick, late Cenozoic loess deposits in the Fairbanks area. It is associated with several distal tephra beds that provide age control and offer the opportunity of its recognition elsewhere in central Alaska. EC tephra (named herein) occurs in the uppermost part of the Dawson Cut Forest Bed and its petrographic and chemical properties point to a co-magmatic relationship with PA tephra, which has not been found in direct association with the forest bed. Both tephra beds are pink and have unusually high Cl in their glass shards, which readily separates them from all other tephra beds in the Fairbanks area. They were produced by discrete eruptions, closely spaced in time. PA tephra has a glass-fission-track age of 2.02 ± 0.14 myr, indicating that the Dawson Cut Forest Bed must be about 2 million years old. The Palisades tephra (named herein) has very similar properties to these two tephra beds, suggesting that the buried forest bed just above it at the Palisades site on the Yukon River, about 250 km west of Fairbanks, correlates with the Dawson Cut Forest Bed.  相似文献   

8.
欧亚大陆的黄土带与旧石器早期人类活动   总被引:3,自引:2,他引:1       下载免费PDF全文
文章对欧洲和亚洲黄土分布资料进行了整理,结合欧亚的旧石器考古资料,发现在旧石器早期,欧亚大陆的考古遗址主要分布在黄土带上,这反映了在旧石器早期,东西文化的交流与传播可能存在着一条"黄土之路"。这条"黄土之路"东至中国华北,在天山、阿尔泰山地区分为两条线,在高加索地区汇合,通过欧洲,一直向西至法国和不列颠群岛。通过对欧洲、中亚和东亚黄土旧石器遗址剖面的对比,发现无论是冰期还是间冰期,在黄土分布区,有的地方一直是人类活动的场所,比如欧洲和东亚,周围的自然环境能使人类生存和生活;而有的地方只有在间冰期才适合人类生活,比如中亚。这需要进一步的工作证明。在S5(MIS 13~15)阶段,无论在欧洲还是亚洲,考古遗址发现的几率都比较大,这也许说明在这个时期人类的活动更为活跃。而且在这条横贯欧亚大陆的古土壤带上,相似的自然环境也许存在着更多的交流。这需要进一步对旧石器文化特征上进行比较方能得出更确切的结论。  相似文献   

9.
Thermoluminescence (TL) dates are presented for the Upper Pleistocene loess sequence that overlies a Paleolithic site 14.5 km southeast of Rawalpindi, northern Pakistan (lat. 33° 30′ 30″ long. 73° 10′ 40″). These dates provide the first dating of Pleistocene blade assemblages in Pakistan, and also indicate that the loess is associated with the last, and not just the penultimate, glaciation of the Himalayas as had been previously thought. The site includes the remains of a structure and numerous blade tools, and may have been used for skin-working or some comparable activity. The ten TL dates presented span the age range 64–24 ka, and imply an early date for blade industries in the northern part of the Indian sub-continent of ca. 45–42 ka.  相似文献   

10.
《Quaternary Science Reviews》2003,22(10-13):999-1010
The loess/palaeosol sequence of Kurtak, situated at the western bank of the upper Yenisei in Middle Siberia, represents one of the best developed Middle and Upper Pleistocene sediment records in Yenisei Siberia. More than 40 m thick loess and loess-like sediments intercalated by at least four pedocomplexes are exposed at a steep erosional slope at the bank of the Krasnoyarsk Water Reservoir. Infrared optically stimulated luminescence (IRSL) and thermoluminescence (TL) dating techniques have been applied on 38 fine grain samples from the upper 23 m of the profile, representing the penultimate and last interglacial–glacial cycle. The IRSL and TL age estimates are in good agreement with the geological estimates up to the last interglacial soil horizon (oxygen isotope substage (OIS) 5e). The luminescence ages show that the lowermost truncated palaeosol of kastanosjem-type is likely to have formed during the penultimate interglacial upon subaerial deposits. Three weak reddish brown palaeosols intercalated by reworked loess-like sediments correlate with early Upper Pleistocene interstadials (OIS5dion of -a), and a succession of humic horizons alternated by cryoturbation processes (Kurtak pedocomplex) is linked with OIS 3. Thick loess deposits between the pedocomplexes show now significant age increase with depth, indicating high accumulation rates at around 23 ka (OIS 2) and 60 ka (OIS 4).  相似文献   

11.
火山灰年代学是判断第四纪沉积物年龄的有效手段。文章报告在江苏三处旧石器遗址(和尚墩、放牛山和将军崖)上部堆积中发现的火山玻璃及初步研究结果。和尚墩遗址的火山玻璃主要出现在两个层位: 上层距地表约45cm,火山玻璃的水合层很薄,年代有可能晚于K Ah火山(7.3ka);  下层距地表约70cm,火山玻璃的水合过程已经完成,时代稍老,大致与日本晚更新世火山同期,至少相当于AT火山,年代等于/大于25ka。遗址中的火山玻璃分为pm型和bw型。形态、屈折率及微量包含物的研究表明,火山玻璃的来源可能与日本的火山喷发无关。江苏旧石器遗址中发现的火山玻璃对判断中国东部地区更新世沉积物时代以及埋藏其中的旧石器遗存年代具标志意义。  相似文献   

12.
Dr. M. Pécsi 《GeoJournal》1987,15(2):151-162
The loess of type localities is subdivided into 3 subseries on the basis of the paleosols allowing even an Eurasian comparison for their lithostratigraphy.
  1. The upper young loess (8–10 m) is most widespread, characterized by 3 sandy loess and 2 intercalated humic loess horizons. The ages of the humic loess horizons H1, H2 are c. 16 ka and 20 ka BP, respectively.
  2. The lower young loess (15–20 m) contains 4 loess packets and 3 chernozem-like paleosols, usually doubled soil complexes (designated MF, BD, BA). The MF paleosol complex, first member of lower young loess is c. 27–28 ka BP (C14 and TL dating). The lower young loess is underlain by a brown forest soil and chernozem-like paleosol-assemblage (MB), probably formed during the last interglacial (c. 105–125 ka BP).
  3. The old loess (c. 20 m) is generally characterized by 6–7 loess, mainly brown forest soil and 2 interbedded fluvial sand layers. The lowermost old loess member and an ochre-red paleosol lie below the Brunhes-Matuyama boundary (0,73 Ma).
  4. The loess is underlain by a subaerial non-loessic sequence (20–40 m) with 5–10 red soils, red clays mostly directly superimposed on and locally interbedded by sand and silty sand. At the base of this sequence of red paleosols usually Uppermost Miocene inland sea deposits are found.
It can be concluded that the reddish paleosol developed under climatic, and in general, ecological conditions (probably warm subhumid with rapid cyclical climatic changes) differing from the cold and semiarid or semidesert environments of typical loess formation. The former conditions were characteristic — from the Lower Pliocene to the Lower Pleistocene — on continental or global scales.  相似文献   

13.
This paper reports the results of an investigation of the Weichselian Upper Pleniglacial loess sequences of Nussloch (Rhine Valley, Germany) based on stratigraphy, palaeopedology, sedimentology, palynology, malacology and geochemistry (δ13C), supported by radiocarbon, TL and OSL dating. Grain-size and magnetic susceptibility records are taken at 5 cm intervals from the Upper Pleniglacial (UPG) loess. The data indicate cyclic variations in loess deposition between ca 34 and 17 ka, when the sedimentation rate is especially high (1.0–1.2 m per ka for more than 10 m). The grain-size index (GSI: ratio of coarse silt versus fine silt and clay) shows variations, which are assumed to be an indirect measurement of wind intensity. The sedimentation rate, interpreted from the profiles, indicates high values in loess (Loess events LE-1 to LE-7) and low or negligible values in tundra gley horizons G1 to G8. OSL ages from the loess and 14C dates from organic matter in the loess show that loess deposition was rapid but was interrupted by shorter periods of reduced aeolian sedimentation. Comparison between the data from Nussloch and other European sequences demonstrates a progressive coarsening of the loess deposits between ca 30 and 22 ka. This coarsening trend ends with a short but major grain-size decrease and is followed by an increase to a new maximum at 20 ± 2 ka (“W” shape). Correlation between the loess GSI and the Greenland ice-core dust records, suggests a global connection between North Atlantic and Western European global atmospheric circulation and wind regimes. In addition, the typical Upper Pleniglacial loess deposition begins at ca 30–31 ka, close to Heinrich event (HE) 3, and the main period of loess sedimentation at about 25 ± 2 ka is coeval to HE 2. Correlation of magnetic susceptibility and grain-size records shows that the periods, characterised by high GSI, coincide with an increase in the amount of ferromagnetic minerals reworked from the Rhine alluvial plain. They suggest enhancement in the frequency of the storms from N–NW. These results are integrated within a palaeogeographical model of dust transport and deposition in Western Europe for the Weichselian Upper Pleniglacial (or Late Pleniglacial).  相似文献   

14.
宁镇地区中更新世环境演变的沉积学研究   总被引:6,自引:0,他引:6  
张强  朱诚  房迎三 《沉积学报》2002,20(2):307-313
句容放牛山剖面ESR测年、粒度以及磁化率的研究结果表明,下蜀黄土作为一种受后生成土作用强烈的风尘堆积,其性状与北方黄土差别很大,主要表现为由于成壤作用及次生风化作用导致粘粒含量增多。该剖面揭示出本区中更新世 5个气候暖湿期,分别是 :15 9~ 16 3ka,192ka,195~ 198ka,2 0 3~ 2 30ka与 311~ 35 0ka。其中第一个相对暖湿期不十分明显,在大致同时期的深海氧同位素 (V2 1- 14 6孔 ) 6阶段当中为一个小的气候回暖波动,第 2、3、4气候暖湿期可大致与西峰黄土S2古土壤层所反映的气候温暖事件相对应,可与深海氧同位素 (V2 1- 14 6孔 )第 7氧同位素阶段大致相对比。其中,前 4个温暖期可大致与老虎山下蜀黄土的标准剖面自上而下的 4个埋藏古土壤层相对应。旧石器考古发掘发现 6、7层有石器,从剖面测年资料及各环境代用指标综合分析得出,当时为暖湿的生态环境(即第 5个气候暖湿期 ),较适宜人类活动,与南京汤山猿人洞研究结果相一致。东北地区庙后山下层文化 (14 0 0~2 30ka)以大石片石器为主,文化面貌兼有华北大小两个石器系统的特征。这与该遗址发掘的石器相类似,这可能说明至少在中更新世中期长江河道应在句容以南。  相似文献   

15.
This paper examines recurrent spatial patterns of prehistoric sites in relation to landforms, alluvial fills, and soil development in the uplands and valleys of the Madaba and Dhiban Plateaus of Jordan. Mousterian lithics (Middle Paleolithic) are largely found on high strath terraces plateaus, where they are associated with red Mediterranean soils. In valleys, Upper Paleolithic sites are often associated with reworked loess deposits of the Dalala allostratigraphic unit. Epipaleolithic occupations are found stratified in deposits of the Thamad Terrace, and Pre‐Pottery Neolithic and Pottery Neolithic occupations are associated with colluvium mantling the Thamad Terrace. The Tur al‐Abyad Terrace and the Iskanderite alluvial inset are the remnants of middle Holocene floodplains, which were attractive areas for Chalcolithic and Early Bronze Age settlements. Sometime around 4000 B.C., stream incision and further lateral erosion destroyed these floodplains. These historic terraces are underlain by alluvial deposits ranging in age from Roman to Early Islamic periods. The sequence of allostratigraphic units, paleosols, and terraces are the basis for reconstructing phases of fluvial aggradation and stream incision during the past 20,000 years. © 2005 Wiley Periodicals, Inc.  相似文献   

16.
Pedological investigations in combination with luminescence dating have been used to reconstruct the genesis and chronology of a sediment succession at Sierentz, France. The sequence comprises loess and palaeosols on top of gravel attributed to the High Terrace of River Rhine. According to the dating results, three phases of soil development occurred during different warm phases of Marine Isotope Stage (MIS) 7 (245–190 ka). Soil development on top of the gravel occurred either during early MIS 7 or during an earlier warm phase, possibly MIS 9. The results imply a minimum age of 250 ka for the formation of the High Terrace in this part of the Upper Rhine Graben, contrary to previous assumptions that correlated gravel sheet deposition with MIS 6 (ca. 150 ka). These results and recent findings at other sites suggest that the chronological setting of terrace formation north of the Alps is much more complex than previously assumed.  相似文献   

17.
Loess‐paleosol sequences are important terrestrial archives of palaeoenvironmental change. Such sequences are rich in pedogenic carbonate, the oxygen and carbon isotopic values of which can provide important palaeoenvironmental information. Although some studies have pioneered the use of O and C isotopes in loess‐paleosol sequences, they are not routinely used as palaeoclimate proxies. In this study we analysed the sedimentology, micromorphology, geochronology and isotopic geochemistry of a Middle Pleistocene loess‐paleosol section, located at Kärlich, Germany. The section studied correlates with the Elsterian glacial (MIS 12) and Holsteinian interglacial (MIS 11). Embedded tephra layers yielded 40Ar/39Ar ages of 466±3 ka, 447±1 ka and 361±3 ka. The sedimentology and micromorphology of the sequence record a shift from accretionary loess accumulation (MIS 12) to prolonged pedogenesis at a stable land surface (MIS 11). Soil carbonate δ18O values record an enrichment of ~3‰ during the accumulation of the loess, reaching peak values comparable with those found in the MIS 11 soil. The δ18O signal is interpreted as reflecting temperature, highlighting the potential of δ18O analysis of European loess soil carbonates as a means of reconstructing palaeotemperature history.  相似文献   

18.
A study has been made of solid and solution electron paramagnetic resonance (EPR) spectra of humic acids from different horizons in a podzolic soil. Hyperfine splitting was observed in the solution spectra of humic acids from all horizons and depended on the strength of alkali and the period of dissolution. The upper organic horizons L, F and O1 contained humic acids with some spectral characteristics in common with lignin. Humic acid from the lower horizons showed different spectra. At least 5 different radical signals were present.  相似文献   

19.
Late Quaternary landscape development along the Rancho Marino coastal range front in the central‐southern Pacific Coast Ranges of California has been documented using field mapping, surveying, sedimentary facies analysis and a luminescence age determination. Late Quaternary sediments along the base of the range front form a single composite marine terrace buried by alluvial fans. Marine terrace sediments overlie two palaeoshore platforms at 5 m and 0 m altitude. Correlation with the nearby Cayucos and San Simeon sites links platform and marine terrace development to the 125 ka and 105 ka sea‐level highstands. Uplift rate estimates based on the 125 ka shoreline angle are 0.01–0.09 m ka?1 (mean 0.04 m ka?1), and suggest an increase in regional uplift along the coast towards the NW where the San Simeon fault zone intersects the coastline. Furthermore, such low rates suggest that pre‐125 ka uplift was responsible for most of the relief generation at Rancho Marino. The coastal range front landscape development is, thus, primarily controlled by post 125 ka climatic and sea‐level changes. Post 125 ka sea‐level lowering expanded the range front piedmont area to a width of 7.5 km by the 18 ka Last Glacial Maximum lowstand. This sea‐level lowering created space for alluvial fan building along the range front. A 45 ± 3 ka optically stimulated luminescence (OSL) age provides a basal age for alluvial fan building or marks the time by which distal alluvial fan sedimentation has reached 300 m from the range front slope. Fan sedimentation is related to climatic change, with increased sediment supply to the range front occurring during (1) glacial period cold stage maxima and/or (2) the Late Pleistocene–Holocene transition, when respective increases in precipitation and/or storminess resulted in hillslope erosion. Sea‐level rise after the 18 ka lowstand resulted in range front erosion, with elevated localised erosion linked to the higher relief and steeper slopes in the SE. This study demonstrates that late Quaternary coastal range front landscape development is driven by interplay of tectonics, climatic and sea‐level change. In areas of low tectonic activity, climatic and sea‐level changes dominate coastal landscape development. When the sea‐level controlled shoreline is in close proximity to the coastal range front, localised patterns of sedimentation and erosion are passively influenced by the pre‐125 ka topography. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

20.
The Quaternary sediments of the West Sussex Coastal Plain have produced a wide range of floral, faunal and archaeological remains. These sediments consist of marine sands and gravels exhibiting transgressive and regressive trends which occur from present day sea-level to c. +43.0 m O.D. and are overlain by terrestrial silts and cold climate periglacial sediments. At the present day coastline, channel fill deposits occur below modern beach levels. New field observations, coupled with a re-investigation of old sites and literature, suggest that five discrete high stands of sea-level may be preserved in the area of the West Sussex Coastal Plain. Age estimates for these deposits suggest that they span large parts of the Middle and Upper Pleistocene (Oxygen Isotope Stages 13 to 5). Conformable relationships between many of the marine and terrestrial sediments suggest that the potential exists within the area to correlate the marine and terrestrial Quaternary stratigraphic records. In addition sediments associated with two of these high sea-level stands are associated with extensive buried landsurfaces covering large areas of the coastal plain. At some locations these intact landsurfaces are associated with evidence for human activity and represent stratigraphic and cultural resources of international importance.  相似文献   

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