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1.
Philip L. Gibbard Martin J. Head Michael J. C. Walker the Subcommission on Quaternary Stratigraphy 《第四纪科学杂志》2010,25(2):96-102
In June 2009, the Executive Committee of the International Union of Geological Sciences (IUGS) formally ratified a proposal by the International Commission on Stratigraphy to lower the base of the Quaternary System/Period to the Global Stratotype Section and Point (GSSP) of the Gelasian Stage/Age at Monte San Nicola, Sicily, Italy. The Gelasian until then had been the uppermost stage of the Pliocene Series/Epoch. The base of the Gelasian corresponds to Marine Isotope Stage 103, and has an astronomically tuned age of 2.58 Ma. A proposal that the base of the Pleistocene Series/Epoch be lowered to coincide with that of the Quaternary (the Gelasian GSSP) was also accepted by the IUGS Executive Committee. The GSSP at Vrica, Calabria, Italy, which had hitherto defined the basal boundary of both the Quaternary and the Pleistocene, remains available as the base of the Calabrian Stage/Age (now the second stage of the revised Pleistocene). In ratifying these proposals, the IUGS has acknowledged the distinctive qualities of the Quaternary by reaffirming it as a full system/period, correctly complied with the hierarchical requirements of the geological timescale by lowering the base of the Pleistocene to that of the Quaternary, and fully respected the historical and widespread current usage of both the terms ‘Quaternary’ and ‘Pleistocene’. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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国际地层委员会最新表决通过第四系为系级年代地层单位,它位于新近系之上,底界由意大利西西里岛的Monte San Nicola"金钉子"定义,也就是由定义格拉斯阶底界的"金钉子"来定义,年龄值约为2.59Ma;更新统的底界也下移到这个位置,格拉斯阶划归更新统,长期争论的第四系的地位和定义问题有望得到解决。 相似文献
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《Russian Geology and Geophysics》2015,56(4):686-688
The Quaternary System/Period represents the past 2.58 million years and is officially subdivided into the Pleistocene and Holocene series/epochs, with the base of the Holocene assigned an age of 11,700 calendar years before AD 2000. The two lowest stages of the Pleistocene, the Gelasian (base 2.58 Ma) and the Calabrian (base 1.80 Ma), have been officially defined and these effectively constitute the Lower Pleistocene Subseries/Subepoch. The Middle and Upper Pleistocene have yet to be formally defined, representing an important future challenge, along with the subdivision of the Holocene, consideration of the ‘Anthropocene’, and fine-scale subdivision elsewhere within the Quaternary. 相似文献
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Mike Walker Sigfus Johnsen Sune Olander Rasmussen Trevor Popp Jørgen‐Peder Steffensen Phil Gibbard Wim Hoek John Lowe John Andrews Svante Björck Les C. Cwynar Konrad Hughen Peter Kershaw Bernd Kromer Thomas Litt David J. Lowe Takeshi Nakagawa Rewi Newnham Jakob Schwander 《第四纪科学杂志》2009,24(1):3-17
The Greenland ice core from NorthGRIP (NGRIP) contains a proxy climate record across the Pleistocene–Holocene boundary of unprecedented clarity and resolution. Analysis of an array of physical and chemical parameters within the ice enables the base of the Holocene, as reflected in the first signs of climatic warming at the end of the Younger Dryas/Greenland Stadial 1 cold phase, to be located with a high degree of precision. This climatic event is most clearly reflected in an abrupt shift in deuterium excess values, accompanied by more gradual changes in δ18O, dust concentration, a range of chemical species, and annual layer thickness. A timescale based on multi‐parameter annual layer counting provides an age of 11 700 calendar yr b2 k (before AD 2000) for the base of the Holocene, with a maximum counting error of 99 yr. A proposal that an archived core from this unique sequence should constitute the Global Stratotype Section and Point (GSSP) for the base of the Holocene Series/Epoch (Quaternary System/Period) has been ratified by the International Union of Geological Sciences. Five auxiliary stratotypes for the Pleistocene–Holocene boundary have also been recognised. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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The Quaternary sediments in the Yangtze delta are loose and lack precise stratification marks in the lithology. Moreover, due to the limitations of dating methods, it is difficult for Quaternary cores to deliver accurate age constraints. Thus, it is a challenge to establish the Quaternary stratigraphic framework. Gravity core LZK1 was drilled on Hengsha Island, Shanghai, in the Yangtze delta, in 2012. The core was terminated at 403.83 m below the local land surface, the uppermost 291.2 m comprising a thick sequence of Quaternary sediments. This study investigated the stratigraphic subdivision and paleoenvironmental change of the Quaternary sediments. From bottom to top, the Quaternary stratigraphic sequence can be subdivided into the lower Pleistocene Anting Formation, Middle Pleistocene Jiading Formation, Upper Pleistocene Chuansha Formation and Nanhui Formation, Holocene Loutang Formation, Shanghai Formation, and Rudong Formation. According to this study, the Hengsha Island area was dominated by a freshwater lacustrine environment during the early Pleistocene, an alternation of shallow lake and shore lake environment during the Middle Pleistocene, a delta plain to lagoonal environment during the early Upper Pleistocene, a fluvial channel to floodplain environment from the LGM (Last Glacial Maximum) to the end of the Upper Pleistocene, and a delta environment during the Holocene. 相似文献
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《Russian Geology and Geophysics》2016,57(9):1312-1320
This study reviews a possible new position of the base of the Quaternary in West Siberia based on paleobotanical and paleomagnetic data in view of ratification of ICS recommendations by the IUGS Executive Committee and the decision of the Interdepartmental Commission on the Quaternary Stratigraphy of Russia to lower the base of the Quaternary (and, therefore, the base of the Pleistocene) at 2.58 Ma. The paleobotanical and paleomagnetic data from two horizons on the West Siberian plain (Kulunda, attributed in part to the formerly Neogene Gelasian Stage, and Kochki, attributed to the Quaternary) were used to identify global cooling that occurred synchronously with a regional cooling phase determined at the base of the Gelasian at Monte San Nicola, Italy. 相似文献
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W. Zech B. Glaser U. Abramowski C. Dittmar P. W. Kubik 《Quaternary Science Reviews》2003,22(21-22):2253-2265
Late Quaternary glacier fluctuations in the Macha Khola valley (Gorkha Himal, Nepal) were reconstructed using relative and absolute dating techniques. Our results indicate that younger moraine complexes were left by Late Holocene (<1.7 cal. ka BP), mid-Holocene (ca 3 cal. ka BP), and Lateglacial (ca 13 cal. ka BP) ice advances. Older Late Quaternary glacier advances occurred during Marine Oxygen Isotope Stages (MIS) 2 and 3–4. No relics of Middle or Early Pleistocene glaciations could be found. During MIS 3–4, glaciers advanced down to an altitude of at least 2150 m a.s.l., corresponding to an ELA depression of approximately 1300 m. At about 3500 m a.s.l., the MIS 2 Macha Khola glacier reached almost the thickness of the former MIS 3–4 glacier and retreated some time before 17.9 cal. ka BP. The Lateglacial glacier advanced again several times to altitudes between 2450 and 3400 m a.s.l. The mid-Holocene glaciers extended much farther down-valley than the Late Holocene ones. Dendrochronological data of Abies spectabilis suggested several periods of unfavourable growth conditions especially at the beginning of the 19th (1820) and 20th (1905) centuries. 相似文献
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湖南第四纪地层划分及其下限 总被引：4，自引：0，他引：4
根据第四纪沉积物特征、孢粉组合、古脊椎动物、古地磁等有关资料，将湖南省区内第四系地层自老至新划分为：泪罗组、新开铺组、陈家咀组、白沙井组、马王堆组、白水江组、丁蜀组及水陆洲组等。原划为早更新世湖仙山组或伍家峪组均为上新世乃至中新世地层，并确定其第四纪下限为２５ＭａＢ．Ｐ． 相似文献
11.
黄河源区第四纪地质研究的新进展 总被引：8，自引：1，他引：8
通过对黄河源区的钻孔、自然露头的研究, 建立了黄河源区的第四纪地层层序。第四纪地层可划分为下更新统、中更新统、上更新统和全新统。下更新统为河湖相沉积; 中更新统主要有湖积物、冰碛物和冰水沉积物; 上更新统主要有湖积物、冰碛物、冰水沉积物、洪积物和河流沉积物; 全新统主要由河流沉积物、洪积物和湖积物构成。黄河源区的冰期可划分为3期, 即末次冰期、倒数第二次冰期、倒数第三次冰期, 末次冰期又可分为2个冰阶。黄河源区的湖泊演化可划分为早更新世、中更新世和晚更新世—全新世3个阶段: 早更新世的湖泊范围小; 中更新世的湖泊范围明显扩大, 在位置上也较早更新世的湖泊南移; 晚更新世的湖泊经历了两次的扩张—收缩变化, 到了全新世, 除现今还发育的几个湖泊外, 大多数地区的湖水已退出, 基本上转变为河流环境。在晚更新世末期到全新世初期, 封闭黄河源区的多石峡被切开, 湖水外泄, 现今的黄河形成了, 同时发生了袭夺长江水系的水流。 相似文献
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珠江三角洲晚第四纪沉积特征 总被引：17，自引：0，他引：17
本文根据钻孔资料和沉积分析资料，研究和探讨了珠江三角洲晚第四纪沉积特征及其沉积层的形成过程。结果表明，珠江三角洲晚第四纪具有两个陆相－海陆过渡相的沉积旋回；在两个沉积旋回之间，包含了一个海退过程。珠江三角洲晚第四纪沉积层是由晚更新世和全新世两套海进河床充填层序和海退进积层序构成。 相似文献
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Development of the steppe zone in southern Russia based on the reconstruction from the loess-soil formation in the Don-Azov Region 总被引：2，自引：0，他引：2
A. Velichko T. D. Morozova O. K. Borisova S. N. Timireva V. V. Semenov Yu. M. Kononov V. V. Titov A. S. Tesakov E.. Konstantinov R. N. Kurbanov 《Doklady Earth Sciences》2012,445(2):999-1002
Herbaceous communities in forest ecosystems on the southern part of the Russian Plain appeared in the Middle Miocene (??10 Ma BP). In the Late Miocene (??7 Ma BP), feather-grass steppe associations appeared among them. In the time span of 2.7 to 2.1 Ma BP (i.e., in the Early Quaternary, according to the current chronostratigraphic scale), the steppe zone arose on the southern Russian Plain in the Don-Azov Region. Seven stages of this zone development here have been distinguished throughout the Quaternary. The first one (Eopleistocene-Early Pleistocene) was characterized by savanna-like subtropic ecosystems. Then, in the Middle Pleistocene, the temperate zone ecosystems (tallgrass prairie-like steppes) developed here and were followed by steppe ecosystems close to the modern ones in Central Europe. The ecosystems of rich-species forb steppes developed in the Late Pleistocene. Finally, in the optimum of the modern interglacial (Holocene), steppes became similar to the modern ones here, but with a slightly higher precipitation. The general trend is characterized by reduction in heat and water provision and increase in aridization progressing from earlier to later stages. 相似文献
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在野外调查和搜集资料的基础上,系统论述了江苏茅山地区瓣生代岩石地层层序,自下而上分为：古近系（下第三系）泰州组、阜宁组、戴南组、三垛组;新近系（上第三系）洞玄观组、雨花台组、方山组;第四系丫吉山组、中更新统、下罚组、全新统。 相似文献
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R.W.O’B. Knox P.N. Pearson T.L. Barry D.J. Condon J.C.W. Cope A.S. Gale P.L. Gibbard A.C. Kerr M.W. Hounslow J.H. Powell P.F. Rawson A.G. Smith C.N. Waters J. Zalasiewicz 《Proceedings of the Geologists' Association. Geologists' Association》2012,123(3):390-393
The ‘Tertiary’, omitted from IUGS-approved timescales since 1989, is still in common use. With the recent re-instatement of the Quaternary as a formal unit, the question arises as to whether the Tertiary too should be reinstated as a formal period, with the ‘Paleogene’ and ‘Neogene’ being downgraded to sub-periods. This paper presents arguments for and against this proposal, stemming from discussions by members of the Geological Society Stratigraphy Commission. It is intended to stimulate discussion of the topic in the wider community. 相似文献
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JIRI CHLACHULA NIKOLAI I. DROZDOV NIKOLAI D. OVODOV 《Boreas: An International Journal of Quaternary Research》2003,32(3):506-520
Multidisciplinary Quaternary investigations in the Minusinsk Basin in the upper Yenisei River region and other southern Siberian continental depressions have produced evidence of prehistoric peopling pre‐dating the last glacial stage (>100 ka BP). Abundant ‘pebble tools’ and bone artefacts exposed from eroded alluvia of the Yenisei River terraces indicate repeated occupation of this territory since the Middle Pleistocene. A new stage of expansion of the early human occupation habitat occurred around the last interglacial (OIS 5e) by a Middle Palaeolithic (Neanderthaloid?) population characterized by a core and flake stone industry and open‐air occupation sites. The key camp/kill‐processing site at Ust‘‐Izhul’, dated to c. 125 ka BP and documenting complex behavioural activities, is so far the most complete in situ pre‐Late Palaeolithic site found in Siberia. This unique record provides new insights into the timing and the palaeoenvironmental conditions of the Pleistocene colonization of north‐central Asia. 相似文献
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哈尔滨荒山剖面是东北地区第四纪典型剖面,因缺乏绝对年龄数据,关于其地层划分及时代还有不同认识.对荒山剖面进行了系统的磁性地层学研究,并与AMS14C、OSL等年代学数据相结合,重新厘定了荒山剖面第四纪地层的年代框架.结果表明,荒山剖面记录了Matuyama负极性时晚期至Brunhes正极性时的沉积,B/M界线位于剖面下部46.7 m,剖面起始沉积年龄早于0.90 Ma.根据AMS14C和OSL年龄确定了全新统和上更新统的底界,对第四纪岩石地层单位的分层标志及顶、底年龄进行了分析,确定第四纪各个岩石地层单位的时代分别为:坦途组的年龄为~12 ka BP,顾乡屯组的年龄为12~79 ka BP,哈尔滨组的年龄为79~138 ka BP,上荒山组的年龄为138~580 ka BP,下荒山组的年龄>900 ka BP.据此建立了荒山剖面第四纪地层系统,为区域地层对比提供依据. 相似文献
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太湖平原西北部第四纪海侵 总被引：4，自引：0，他引：4
通过对武进漕桥和金坛水北等地钻孔及剖面样品中古生物组合分析，结合岩性、古气候、古地磁等综合研究，证实太湖平原西北部第四纪以来曾发生过三次较大规模的海侵，即晚更新世早期的太湖海侵、晚更新世晚期的Ge湖海侵和全新世的镇江海侵。 相似文献
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东海陆架第四纪地层层序的初步研究 总被引：2，自引：0，他引：2
根据我局在东海陆架所获得的区域海洋地质和工程地质调查资料,对已有的第四纪地质孔进行统一的第四纪地层划分和对比,建立了东海陆架第四纪地层层序。将第四系四分,从老到新依次为下更新统西湖组、中更新统金鸡山组、上更新统西泠组、全新统海礁组或下全新统鸡骨礁组、中全新统大戟山组、上全新统嵊泗组。 相似文献
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大兴安岭哈拉哈河-绰尔河第四纪火山分期: K-Ar年代学与火山地质特征 总被引：9，自引：6，他引：3
大兴安岭中部哈拉哈河-绰尔河第四纪火山区分布有34座火山,这些火山总体呈北东向带状分布,火山岩分布面积约400 km2,岩性主要为碱性橄榄玄武岩.根据火山地质特征,结合火山岩K-Ar测年结果,哈拉哈河-绰尔河第四纪火山可进一步划分为早、中、晚更新世和全新世4期.早更新世火山岩,由于被后期火山岩覆盖,主要分布于火山区周边和出露在河谷中.中更新世火山活动最强,不论火山数量(27座)还是熔岩流规模都超过该区第四纪火山的一半以上.晚更新世时期火山活动趋弱,火山活动范围缩小,只局限于小范围区域.全新世火山活动又进入新的高峰期,强爆破式喷发和规模宏大的熔岩流,以及保存完好的熔岩流地貌是全新世火山之特点. 相似文献