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《Quaternary Science Reviews》2003,22(15-17):1717-1728
Sedimentological and geochemical proxy records of a deep-sea sediment core from the southern central Nordic seas were used to reconstruct the development of glacial and interglacial conditions during the Early and Middle Pleistocene, i.e., late Matuyama to middle Brunhes Chron (1.5–0.35 Ma). An enhancement of both glacial and interglacial characteristics is observed during early Brunhes oxygen isotope stages (OIS) 16 and 15, respectively. Any intensification of the climatic conditions prior to this, as was previously described for the eastern part of the Nordic seas, is not recognized at our study site. It is further shown that the glacial–interglacial environmental contrasts increased from the early to the middle Bruhnes Chron. Of all glacial periods investigated OIS 12 is characterized by the most severe conditions, showing both maximum input of iceberg-rafted debris (IRD) as well as planktic foraminiferal δ18O values comparable to those of the Last Glacial Maximum. Among the interglaciations, OIS 11 is by far the longest interval and the first to show fully developed interglacial conditions, i.e., Holocene-like δ18O values and a minimum of IRD deposition. Hence, our comparison supports bottom water δ18O studies that have indicated the existence of a gradual intensification of glacial–interglacial climate contrasts during the Middle Pleistocene. 相似文献
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《Quaternary Science Reviews》2007,26(17-18):2067-2089
The continental vertebrate fauna of Cúllar Baza-1 (Granada, Spain) occur immediately above the Matuyama/Brunhes polarity boundary, and therefore represent an initial record for the Middle Pleistocene. All polarity zones for the Late Pliocene through Middle Pleistocene are found in an 80 m section, which includes this fossil quarry. The existing collection of abundant remains of micro-mammals, macro-mammals and lithic artifacts (indicating human activity) can now be assigned an earliest Middle Pleistocene age of 0.75 Ma. Another section, 25 km across the Neogene Baza Basin, also has the Matuyama/Brunhes polarity boundary. However, in this case the Huéscar-1 fossil quarry and the Puerto Lobo sites are both below the polarity boundary, thus representing a record of the late Early Pleistocene at ∼0.9 Ma. Differences in micro-mammal species across these Matuyama/Brunhes boundaries are significant and justify an approximately coincident biostratigraphic boundary between the Biharian and Toringian stages. 相似文献
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对北京大兴凸起南部PGZ05孔(孔深255 m)全孔岩心进行了磁性地层、岩石地层、AMS14C测年研究,在系统性的古地磁样品采集(440块岩样)、处理和测试基础上,分析认为255 m的岩心记录了布容正向极性时(Brunhes)、贾拉米洛(Jaramillo)极性亚时、奥尔都维(Olduvai)极性亚时和高斯正极性时(Gauss)。在此磁性年代框架上,结合AMS14C测年及岩性特征,对PGZ05钻孔剖面进行第四纪地层划分,确定下更新统、中更新统、上更新统和全新统的分布深度及年代,将更新统的底界(Q/N)定位于181. 35 m处,亦为一重要岩性(棕红色半固结黏土)界限,中更新统、上更新统、全新统的底界分别定位于75. 60 m、57. 20 m、17. 35 m处。研究成果为大兴凸起南部第四纪地层划分与对比、古地理环境演变及区域地层研究提供了可靠的地层年代学框架,具有重要地质意义。 相似文献
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磁性地层学研究是建立渤海地区第四纪沉积序列地层年代框架的主要技术手段之一。通过对渤海海峡地区BHS01孔(孔深121.3 m)进行详细的磁性地层学研究,结果表明:BHS01孔岩心记录了布容(Brunhes)正极性时至松山(Matuyama)负极性时底部,包括贾拉米洛(Jaramillo)和奥尔都维(Olduvai)正极性亚时。早、中更新世界线即布容(Brunhes)正极性时/松山(Matuyama)负极性时界限(B/M)深度位于该钻孔的46.4 m处。根据沉积速率,推测钻孔底部121.3 m处的年龄约2.25 Ma。综合沉积物的岩性、磁性及沉积速率变化特征,将BHS01孔沉积物记录的区域沉积过程自下而上划分为3个阶段:阶段Ⅰ(2.25～1.46 Ma)以河流相沉积为主;阶段Ⅱ(1.46～0.78 Ma)为稳定的湖泊相沉积;阶段Ⅲ(0.78～0 Ma)发育海陆交互相沉积。这一研究为该钻孔提供了可靠的年代标尺,为渤海海峡及邻区第四纪地层的划分对比和沉积演化过程提供了新的依据。 相似文献
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Loess stratigraphy in central China 总被引：12，自引：0，他引：12
George Kukla 《Quaternary Science Reviews》1987,6(3-4)
The loess deposits in central China record world-wide climate changes of the last 2.5 Ma. Numerous climatic oscillations are marked by alternating loess and soil units with continuous coverage of the Matuyama and Brunhes Epochs. Magnetic susceptibility of the deposits correlates closely with the oxygen isotope record of the deep-sea sediments and provides an independent measure of climate and time.The key marker bed of the chinese loess sequence is the paleosol S5, the time equivalent of the mid-Brunhes oxygen isotope stages 13, 14 and 15. It marks a prolonged interval of warm humid climate lasting from approximately 615 to 470 thousand years ago. Several episodes of river downcutting coincide with deposition of the exceptionally thick loess units L1 (oceanic oxygen isotope stages 2 to 4) L2 (stage 6), L5 (stage 12) L6, (stage 16) L9 (stage 22) L15 (stage 38 about 1.15 Ma) and WS4 (about 2.3 Ma). These erosional events are interpreted as a result of episodic uplift of the Loess Plateau.The deposition of the earliest loess layers between 2.5 and 2.3 Ma ago marks a first order shift from warm and humid environments toward harsh continental steppes comparable to those of the Middle and Late Pleistocene. Little, if any lithologic or paleontologic changes were noted within or above the Olduvai magnetozone, so that the proposed Plio/Pleistocene boundary at approximately 1.65 Ma has no lithostratigraphic and biostratigraphic representation in the chinese loess series.Comparison with the Deep Sea Drilling Program core 552A in the North Atlantic and with the Santerno River section near Bologna shows that the occurrence of the earliest loess in China coincides with the timing of the first significant ice rafting in the North Atlantic and with the appearance of cold water foraminifers in the marine deposits of northern Italy. An extension of the stage system of the oxygen isotope signal extended back to the Gauss-Matuyama boundary is proposed. 相似文献
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中国第四纪地层 总被引：32，自引：0，他引：32
本文综述了中国第四纪沉积类型及第四系的划分,并与国际第四系划分进行了对比。指出中国第四纪沉积物分布广泛,种类繁多,以陆相沉积为主。按其成因主要有风成黄土堆积、河一湖相沉积、冲一洪积堆积、冰川沉积、洞穴堆积、风化壳残积（红土）、火山堆积和海相沉积等。各种沉积物都有很好的剖面,尤其是黄土和河一湖相沉积更为连续完整。按中国第四纪地层发育的实际情况,第四系的底界应置于松山一高斯极性转换界线（Ｍ／Ｇ,２．６ＭａＢ,Ｐ,）;第四系内部划分为更新统（Ｑｐ）和１４新统（Ｑｈ）,界线在１１０００ａＢ,Ｐ,。更新统进一步划分为下、中和上３个阶(Ｑｐ１, Ｑｐ２, Ｑｐ３), Ｑｐ２／Ｑｐ１的界线为布容一松山极性转换界线（Ｂ／Ｍ; ０．７８ＭａＢ,Ｐ,）;Ｑ(ｐ３／Ｑｐ２的界线为本次间冰期的起始时间（０．１２８ＭａＢ,Ｐ,）。 相似文献
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沧县隆起是渤海湾盆地的重要构造单元之一,对该区地层长尺度的沉积环境演化分析可为盆地演化、水工环地质勘查以及区域古地理研究等提供基础资料。本文通过对沧县隆起上的ZKQ1孔岩芯详细的沉积特征研究和综合测井、测年（AMS14C、OSL、古地磁）等研究工作,结果表明：①B/M界线位于62.80 m;M/G界线位于130.60 m;钻孔底界年龄不早于3.6 Ma;上更新统、全新统底界分别位于50.30 m、13.10 m。②沧县隆起3.6 Ma以来的沉积环境演化为晚上新世（<3.6—2.58 Ma）由泛滥平原→湖相三角洲→曲流河演变;早更新世以泛滥平原为主,夹湖沼和分支河道;中更新世存在沉积间断;晚更新世—全新世表现为三期河海交互作用沉积演化时期。 相似文献
9.
北京怀柔HR_（88－1）钻孔剖面磁性地层学研究 总被引：3，自引：0，他引：3
在系统古地磁样品采集、处理和测量的基础上，运用磁性地层学的研究方法，对北京怀柔地区ＨＲ（８８－１）钻孔剖面进行了详细地层划分，分别确定了该区上新统、下更新统、中更新统和上更新统的分布深度及地质年代。 相似文献
10.
北京怀柔HR_（88－1）钻孔剖面磁性地层学研究 总被引：6，自引：0，他引：6
在系统古地磁样品采集、处理和测量的基础上，运用磁性地层学的研究方法，对北京怀柔地区ＨＲ（８８－１）钻孔剖面进行了详细地层划分，分别确定了该区上新统、下更新统、中更新统和上更新统的分布深度及地质年代。 相似文献
11.
沧县隆起是渤海湾盆地的重要组成部分。通过对沧县隆起上施工的350m深ZKT1钻孔沉积特征、测年(AMS14C和OSL)及磁性地层研究,并与CGZ5、BZ2孔磁性地层及海侵层对比,结果发现:沉积岩层M/G(松山/高斯,Matuyama/Gauss)极性带界线埋深存在较大沉积差异,B/M(布容/松山,Brunhes/Matuyama)极性带界线趋于一致,3期海侵层基本稳定;早更新世沧县隆起不同部位存在沉积差异,继承了古近纪以来的断陷沉积;中更新世-晚更新世沧县隆起准平原化,整体处于同一稳定下沉的沉积演化环境;晚更新世以来,发生三期区域性层位较稳定的海陆交互作用,形成滨海冲积平原。本文可为渤海湾地区新构造活动性研究及区域古地理恢复与地质演化提供参考。 相似文献
12.
Simona Avnaim‐Katav Ahuva Almogi‐Labin Amir Sandler Dorit Sivan Naomi Porat Ari Matmon 《第四纪科学杂志》2012,27(7):675-686
The current detailed chronostratigraphic framework of the last 1 Ma of an eastern Mediterranean sequence (Haifa Bay, Israel) aims to examine the relative roles of sea‐level changes, climate and tectonics. Seven continuous marine cores, up to ～120 m long, were recovered from shallow water depths. The cores were dated by optically stimulated luminescence, 14C, magnetostratigraphy, 230Th/234U, 26Al/10Be, occurrence of index fossils and correlated to the global sea‐level curve and Marine Isotope Stages (MIS). The sedimentary sequence accumulated during the last ca. 1.0 Ma consists of 21 transgression–regression units with hiatuses between them. Five marine/terrestrial cycles, which occur in the lower part of the sequence, are attributed to the Jaramillo subchron and the Brunhes–Matuyama boundary, and correspond to MIS 29–21. The top ～50 m includes three sedimentary cycles deposited in the last ca. 400 ka. The regressive phases during this interval correspond to Glacial MIS 8, 6 and 2, while the transgressions correspond to Interglacial MIS 11, 7, 5 and 1. Thus, for the first time, this study documents the longest Quaternary succession dated so far in a key area of the Levant, sensitive to global history of sea‐level changes and glacial/interglacial fluctuations. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
13.
LEI Xiangyi YUE LepingLoess Research Section Department of Geology Northwest University Xi'' an Shaanxi 《《地质学报》英文版》1998,72(4):420-431
The Fengzhou loess section is very typical in the Qinling Mountains. The section, which is about 82 m thick and underlain by Neogene red clays, consists of 33 layers of loess and 33 layers of palaeosol. It covers the Brunhes normal polarity zone and Matuyama reversed polarity zone, and the B/ M boundary is located in the middle part of loess layer 8 (L8). The loess of the Matuyama reversed polarity zone records the Jaramillo, Olduvai and Reunion normal polarity subchrons. The boundary between the Matuyama reversed polarity zone and Gauss normal polarity zone (M / Ga) appears on the lithological boundary between loess and Neogene red clays. Loess accumulation in the Fengzhou section started before 2.48 Ma B.P. Based on the stratigraphical structure, the material composition and magnetic susceptibility curve of the Fengzhou loess section, the palaeoclimatic changes during the last 2.48 Ma in the Qinling Mountains are subdivided into 66 cold-dry and warm-humid stages, equivalent to 33 climatic cycles. The 相似文献
14.
中国黄土研究新进展(一)黄土地层 总被引：39，自引：15，他引：39
本文扼要介绍最近几年中国黄土研究中的土壤地层学、磁性地层学、气候地层学、第四纪下界及海陆古气候对比等方面的新进展。根据新发现的黄土剖面,中国黄土中共可区分出37个土壤地层单位。中国黄土底界的古地磁年龄为2.5MaB.P.。2.5Ma以来,中国北方共经历了37次大的冷暖交替。2.5MaB.P.前后,全球气候出现了一次大的转型事件,它可作为第四纪的开始。中国黄土-古土壤系列同深海氧同位素记录在1.7Ma至今的时段上可以很好的对比;2.5Ma至1.7MaB.P.的气候变化,以黄土记录较为明确。 相似文献
15.
The sedimentary record from Lake George provides the longest relatively continuous Quaternary continental sequence yet available from Australia, and may record one of the longest Upper Cainozoic lacustrine records in the world. Palaeomagnetic analysis of a 36 m core from the lake floor identifies a sequence of deposition extending through the Brunhes and Matuyama, to the Gauss magnetic Chron. A longer core from the same site, but with incomplete recovery, extends to 72 m in lacustrine sediment; the age of the base of this core estimated by extrapolation is between 4.2 and 7 Ma. As there are still older and deeper sediments in the basin, extending to an estimated depth of 134 m, the age of the tectonic formation of the Lake George basin must be reckoned as Middle Miocene or older. The pattern of facies organisation through time demonstrates a phase of deep water deposition extending from the base of the cored sequence (72 m) up to 51.5 m, at which time a major change took place. A disconformity developed at this level, associated with a period of deep weathering and a prolonged phase of slope mantle deposition (from 51.5 to 30.8 m). A gradual return to lacustrine environments, with diminishing proportion of slope wash detritus, resulted in increased rates of deposition coincident with the Jaramillo Subchron at 21.5 m. Thereafter, throughout the Brunhes magnetic Chron, lacustrine conditions dominated, varying from deep to lake dry conditions in a rhythmic fashion, and reflecting the major climatic oscillations of the past 700 000 years, becoming more regular in the past 400 000 years. The pollen analytical record of the upper 8.6 m, covering the last 350 000 years, provides the main framework for the reconstruction of climatic history. The pollen and algal records indicate a sequence of vegetation and lake level changes, in which four major glacial/interglacial cycles are correlated with stages 1 to 10 of the 180 marine record. This provides by far the longest continuous biostratigraphic framework for the Quaternary period in Australia. Comparison between the palaeoclimatic record and the lake level evidence shows that there is no simple correlation between the lake level fluctuations and the glacial/ interglacial oscillations. In fact, major falls in the lake level occured both at the peak of cold glacials and during the warm interglacials. Though the falls in the lake levels during a warm period (interglacial) can be explained by high rates of evaporation, drying during maximum cold can be explained best in terms of a fall in precipitation. Permanent to deep‐lake conditions generally occurred during intermediate cool periods following warm intervals, when perhaps the seas were still warm and low rates of evaporation on land prevailed. On the other hand, short periods of shallow to deep lake levels also occurred during warm (interglacial) periods, showing that these were associated with reasonably high rates of precipitation. 相似文献
16.
JÓN EIRÍKSSON RÉS I. GUDMUNDSSON LEÓ KRISTJÁNSSON KARL GUNNARSSON 《Boreas: An International Journal of Quaternary Research》1990,19(1):39-55
Palaeomagnetic measurements have been carried out on lava flows and volcaniclastic sedimentary rocks of Upper Pliocene and Pleistocene age from sections on the Tjömes Peninsula and a core section from the island of Flatey off North Iceland. Earlier palaeomagnetic work in the area is reviewed, and new data on the stratigraphy of the Hoskuldsvik Group on Tjörnes are presented. A revised polarity column based on our resultsisset upfortheoutcropson Tjörnes, including twoadditionalnormalsubchronswithin the Matuyama. Our palaeomagnetic results indicate that the rocks penetrated by the Flatey drillhole accumulated during the Matuyama. Age estimates for the Upper Tjömes sequence are reviewed, and correlation alternatives indicate that the earliest glaciation of Tjörnes took place either at c.2 Ma or near the Gauss/Matuyama boundary at c. 2.5 Ma. Correlation of individual Matuyama subchrons remains uncertain. A comparison of the climatic evidence from the Tjörnes area with data on oxygen isotope and carbonate variations at DSDP site 552A is used to evaluate correlation alternatives. 相似文献
17.
Three lacustrine sections in the Nihewan Basin, Xiaodukou, Donggutuo and Xiaochangliang (40.1-40.4°N; 114.6-114.7°E), were closely sampled for magnetostratigraphic and deposition cycle analysis. Rock magnetic investigations show that the characteristic remanent magnetization of the sediments is mainly carried by magnetite and hematite. The Xiaodukou sequence is one of the most complete sections in the basin and has recorded substantial parts of the Brunhes and Matuyama chrons back to the termination of the Olduvai subchron. Several subchrons within the Matuyama period have been documented such as the Jaramillo, the Cobb Mt. and others. The Matuyama/Brunhes boundary, the Jaramillo, as well as the Cobb Mountain events were observed also at Donggutuo. On the basis of grain size and susceptibility data and of field investigations, the sections are divided into two longer lasting lacustrine episodes with a fluvio-lacustrine deposit in between. They are structured by 15 high-frequency deposition sub-cycles. In each cycle, the grain size fines upwards, while magnetic susceptibility decreases. This behavior is due to cyclic water level change of the ancient lake Nihewan. At Xiaodukou, the variations of the 0.2 to 7.5 μm grain size fraction can be correlated with the marine oxygen isotope stages OIS 64-OIS 11. The grey-green clayey to silty Paleolithic stone artifact layers at Xiaochangliang and Donggutuo are located at depths of 55.4 m and 43-38.7 m, respectively. They were buried when the lake-level was rising. The artifact layers have been deposited around the Cobb Mountain event during the sedimentary sub-cycle 6 of the older lacustrine phase corresponding to OIS 35, 36. Thus in contrast to the results of other studies, the estimated age of the Xiaochangliang stone artifact layer does not exceed 1.26 Ma, while the Donggutuo stone artifact layers date back to 1.21-1.15 Ma. This age determination brings the Nihewan hominids in close relation to the findings of Homo Erectus at Lantian on the Chinese Loess Plateau. 相似文献
18.
Gilles Rixhon Didier L. Bourlès Régis Braucher Lionel Siame Jean‐Marie Cordy Alain Demoulin 《Boreas: An International Journal of Quaternary Research》2014,43(2):528-542
It is still disputed whether very old archaeological and palaeontological remains found in the Belle‐Roche palaeocave (eastern Belgium) pertain to the Early (～1 Ma) or Middle (～0.5 Ma) Pleistocene. Here, in situ‐produced cosmogenic 10Be concentrations from a depth profile in nearby sediments of the Belle‐Roche terrace (Amblève Main Terrace level) are used as an indirect solution of this chronological issue. The distribution of 10Be concentrations in the upper 3 m of this profile displays the theoretically expected exponential decrease with depth. Assuming a single exposure episode, we obtain a best fit age of 222.5±31 ka for the time of terrace abandonment. However, below 3 m, the 10Be concentrations show a marked progressive increase with depth. This distinctive cosmogenic signal is interpreted as the result of slow aggradation of the fluvial deposits over a lengthy interval. Modelling of the whole profile thus suggests that the onset of the terrace formation occurred at around 550 ka, with a sediment accumulation rate of ～20 mm ka?1. Based on two slightly different reconstructions of the geomorphic evolution of the area and a discussion of the temporal link between the cave and Main Terrace levels, we conclude that the fossil‐bearing layers in the palaeokarst pertain most probably to MIS 14–13, or possibly MIS 12–11. This age estimate for the large mammal association identified in the Belle‐Roche palaeokarst and the attribution to MIS 14–13 of a similar fauna found in the lowermost fossiliferous layers of the Caune de l'Arago (Tautavel) are in mutual support. Our results therefore confirm the status of the Belle‐Roche site as a reference site for the Cromerian mammal association in NW Europe. 相似文献
19.
渤海湾西岸天津平原南部静海区400m深CGZ5孔、大港区500m深TPZ1孔岩心的岩石地层、磁性地层、14C测年、微体古生物研究表明,2个钻孔底部分别进入到定年3.6Ma的高斯(Gauss)正极性带和定年4.5Ma的吉尔伯特(Gilbert)极性带上部;位于西侧沧县隆起的CGZ5孔2.58Ma古地磁M/G(松山/高斯,Matuyama/Gauss)极性带界线位于225m,位于东部黄骅坳陷西斜坡的TPZ1孔该界线位于208m;0.78Ma的B/M(布容/松山,Brunhes/Matuyama)极性带界线分别位于55m和68.6m。结合微体化石分析、3期海侵地层的确定以及岩石地层特征,可判断CGZ5孔和TPZ1孔上更新统底板分别位于55m 和63.4m。依据末次盛冰期低水位域潴育化黏土层位,确定全新统分别厚14.8m和16.5m。上述2孔之间的黄骅坳陷板桥主凹陷中CQJ4孔,B/M和M/G界线分别位于74m和340m。西部CGZ5孔显现整个中更新统缺失,东部TPZ1孔中更新统仅厚5.3m。推测这一地层间断可能是由于渤海海盆在中更新世初期发生快速断陷,在河流到海盆的高差加大的背景下,河流输送物大部流入海盆,海盆边缘的沧县隆起和相邻的滨海平原发生了过路作用。在“源到汇”古地理状况变迁过程中形成的东部大平原,中更新世的沉积动力学背景需要进一步研究。 相似文献
20.
E. A. Vangengeim A. N. Lungu A. S. Tesakov 《Stratigraphy and Geological Correlation》2006,14(6):655-667
The Vallesian lower boundary and “Hipparion-datum” are estimated as ranging in age from 11.2 to 10.7 Ma in Central to Western Europe and Western Asia. Judging from complete sections of Sarmatian marine sediments in the Tamanskii Peninsula and Transcaucasia with known paleomagnetic characteristics, the above dates correspond to the lower upper Sarmatian (Khersonian) of the Eastern Paratethys, although in Moldova and Ukraine the earliest hipparion remains are associated with the middle Sarmatian (Bessarabian) sediments. The normally magnetized middle Sarmatian deposits in hipparion localities of Moldova are correlative with an upper part of Chron C5An (upper boundary 11.9 Ma old) or, less likely, with Subchron C5r2n (base 11.5 Ma old). Consequently, the first occurrence of hipparions in southeastern Europe is recorded in the Middle Miocene, i.e., 0.7 m.y. (or 0.3 m.y.) earlier than the date of 11.2 Ma formerly accepted for the Vallesian lower boundary in Europe. Possible reasons for disagreements in age determination of the Vallesian base are discussed. 相似文献