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二叠系-三叠系界线的事件地层学标志 总被引:2,自引:0,他引:2
<正> 传统的二叠-三叠系界线,是以喜马拉雅山的Otoceras层的底作为三叠系底界(Die-ner 1912)。70年代以来,国际上提出了多种方案(Waterhouse 1973,1976;Kozur 1977;Newell 1978),我国80年代出现了分歧意见(李子舜、姚建新1984;李子舜、詹立培等1986)。1986年在意大利举行的“西特提斯南阿尔卑斯的二叠系及二叠-三叠系界线国际 相似文献
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陆相二叠系-三叠系界线研究进展 总被引:8,自引:0,他引:8
着重介绍了几个目前陆相二叠系—三叠系界线(TPTB)研究的重点剖面及其生物地层学研究进展;分析了陆相二叠系—三叠系界线综合地层学研究现状,包括生物地层学、事件地层学、同位素年代学、磁性地层学和层序地层学等;剖析了陆相二叠系-三叠系界线地层学研究中存在的问题及进一步的研究方向。生物地层方面,陆相二叠系-三叠系界线附近存在晚二叠世与早三叠世生物混生的层位,其中不同类别生物的时间界线常不一致,又由于陆相界线地层中含脊椎动物化石的层位一般较少,以脊椎动物化石(Lystrosaurus)为标准的精确界线常不确定,因而需重新寻找并确定陆相三叠系底界的标准化石。事件地层标志可能会成为连结海、陆相二叠系-三叠系界线地层高精度对比的纽带。 相似文献
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<正> 四川广元上寺剖面是我国著名的二叠系-三叠系界线剖面之一,李子舜等(1986)和杨遵仪等(1987)曾推荐它为国际二叠系-三叠系界线候选层型剖面。60年代初中国科学院南京地质古生物研究所川北地层队率先对这个剖面的二叠系和三叠系进行调查。此后,四川二区测队、西南地质研究所、四川石油管理局、武汉地质学院、成都地质学院等均先后到此作了大量工作。70年代末杨遵仪教授组织的界线专题小组(IGCP 106项和 203 相似文献
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华文 《河北地质矿产信息》2005,(2):24-24
经过五年两个阶段的工作,涉及近50个阶和几个具有重要国际意义的建阶界线层型研究取得显著进展。其中,二叠系至三叠系界线、三叠系乐平统底界、石炭系维宪阶底界等成果显著,已被国际地层委员会批准在中国立“金钉子”,作为全球划分地层、确定界线的标准。滹沱系地层建系研究已初步建立起同位素地质年代格架, 相似文献
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20 0 1年 3月 7日从阿根廷国际地质科学联合会秘书处传来喜讯 ,经过 1年多 3轮国际投票后 ,全球二叠系—三叠系界线层型剖面和点被国际地质科学联合会最终正式确定在中国浙江长兴县的煤山剖面 2 7c层之底。这是我国地学界的一大荣誉 ,也表明了我国学者在该学科领域的研究处于国际领先地位。二叠系—三叠系界线既是两个系的分界 ,又是古生界和中生界的分界。它与显生宙最大的一次生物绝灭事件相一致 ,与许多重大的地质稀有过程相伴随 ,也是全球古构造格局重大转变的标志。因此 ,它一直是国际地质学、生物学界的重点关注课题。国际地层委员会… 相似文献
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南非陆相二叠系-三叠系界线研究进展 总被引:2,自引:2,他引:2
从岩石地层研究着手,介绍了南非卡鲁盆地内综合地层研究的相关成果.在生物地层方面,脊椎动物和植物化石的研究在该区具有传统优势,孢粉化石的研究则是在最近几年才取得较大进展,在陆相界线地层研究中菌孢化石在二叠系-三叠系界线处约1 m厚的地层内的富集事件属首次报道.在地球化学地层方面,南非有机碳同位素在二叠系-三叠系界线附近的变化趋势与海相二叠系-三叠系界线地层存在相似的对应关系,可以作为海、陆相界线地层对比的辅助标志.在磁性地层方面,南非卡鲁盆地内的磁极性存在从反向到正向然后再反转(R-N-R)的变化,二叠系-三叠系界线则位于第一反向极性带的顶部.同时,结合目前全球陆相二叠系-三叠系界线的研究现状及特点,分析了陆相界线地层研究中存在的基本问题,指出华南地区可能为突破传统观念的研究地区,陆地事件地层研究意义重大. 相似文献
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<正> 不久前,国际地科联在巴黎举行的一次工作会议上,决定第二十八届国际地质大会1989年在美国召开。中国地质学会最近就我国参加第二十八届国际地质大会的论文选题内容提出初步意见,在适当时候还将发布征文启事。论文选题内容如下:一、基础地质1.矿物学:晶体结构分析,新矿物。2.地层古生物学:前寒武系晋宁梅树村剖面,泥盆系-石炭系、二叠系-三叠系界线。 相似文献
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This paper is dedicated to the global correlation of the marine Permian-Triassic boundary layers based on some published and original data on the δ13Corg and δ13Ccarb values obtained for the section along the Suol Creek (Setorym River, southern Verkhoyansk region). The section includes six carbon-isotope intervals readily distinguished in the corresponding curves obtained for several Permian and Triassic reference sections in Eurasia and North America including palleontologically well substantiated sections of central Iran, Kashmir, and South China. This provides grounds for assuming the Permian-Triassic boundary’s position in the Suol Creek section as being close to the carbon-isotope minimum of Interval IV. In the light of new data, the upper part of the Upper Permian Changhsingian Stage in Siberia is proposed to correspond in range to the Otoceras concavum range zone, and the lower substage of the Lower Triassic Induan Stage, to the Tompophiceras pascoei and Wordieoceras decipiens zones. The Otoceras concavum Zone of the Verkhoyansk region in its new understanding is likely correlative with the upper Changhsingian Hypophiceras triviale Zone of Greenland. Carbon-isotope intervals II, III, IV, and V defined in the Permian-Triassic boundary layers of the Verkhoyansk region, which are traceable in several reference sections of Eurasia and North America, evidently coincide with the period of some intensification of the volcanic activity in the initial late Changhsingian and with the first phases of extensive eruption of Siberian trappes in the terminal Changhsingian and initial Induan ages. New data imply the probable survival of some ammonoid species from the superfamily Otoceratoidea after the mass extinction of organisms in the terminal Permian Epoch. 相似文献
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Ammonoid Succession of Setorym River (Verkhoyansk Area) and Problem of Permian—Triassic Boundary in Boreal Realm 总被引:4,自引:0,他引:4
YuriDZakharov 《中国地质大学学报(英文版)》2002,13(2):107-123
The presence of a single Otoceras species (O.boreale), morphologically very variable, at the base of the Nekuchan Formation in Verkhoyansk, we believe, is to be obvious. Some morphological evidence leaves no doubt that two described morphs of O. boreale are s strictly corresponding sexual dimorphic pair. It is very likely that Kummel‘s idea that Canadian. O. concavum Tozer is an invalid species is truthful, considering the range of variability seen in larger Siberian and Himalayan Otoceras fauna. Just above the upper Tatarian Imtachan Formation, the six stages of ammonoid succession can be recognized within the lower part of the Nekuchan Formation in the Setorym River Section:(a) Otoceras boreale;(b) Otoceras boreale-Tompophiceras pascoei; (c) Otoceras boreale-Tompophiceras pascoei-Aldanoceras;(d)Tompophiceras pascoei-Otoceras boreale-Aldanoceras;(e) Tompophiceras morpheous-T.pascoei-Aldanoceras;(f) Tompophiceras more pheous-T.pascoei-Wordieoceras domokhotovi-Ophiceras transitorium;(g)Tompophiceras morpheous-T.pascoei, corresponding to the Otoceras boreale and Tompophiceras morpheous zones. In spite of the domination of Otocerataceae or Xenodiscaceae in both oif these zones and the presence of some Permian type conodonts in the lower part of the Otoceras boreale Zone, they seem to be early Induan in age on the basis of the following arguments:(1) in contrast to the underlying regressive type sediments of the Upper Tatarian Imtachan Formation, both the Otoceras boreale and the Tompophiceras morpheous zones of the lowermost part of the Nekuchan Formation correspond to the single transgressive cycle;(2)typical early Induan ammonoids (Ophiceras and Wordieoceras) have been recognized in the Tompophiceras morpheous zone; (3) all described ammonoid succession stages (a-g) are characterized by very gradual changes and therefore correspond to the different parts of the single zone or to the different zones of the same stage, but not to the different systems (Permian and Triassic);(4)elsewhere in the Boreal realm (Arctic Canada), the conodont index species for the base of the Triassic, Hindeodus parvus, has been reported from the Otoceras boreale Zone. A new scheme of the phylogeny for the Otocerataceae and its Induan-Olenekian offspring (Araxceratidae-Otoceratidae-Vavilovitidae n.fam.-Proptychitidae-Arctoceratidae) and Xenodiscaceae is offered. 相似文献
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论两种二叠-三叠系界线 总被引:5,自引:2,他引:3
<正> 近年来许多地质学家围绕着二叠-三叠系界线的划分问题做了大量的工作,关于二叠-三叠系之间界线定义,尚未取得一致意见。目前议论较多的主要是两条界线:1.Otoceras层之底——传统界线 相似文献
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This paper proposes a scheme for the definition of the Lower Triassic Induan-Olenekian boundary (IOB) based on investigation of sections in Chaohu, Anhui Province, China as well as data accumulated from other studies elsewhere. The conodont Neospathodus waageni is suggested as the index fossil of the boundary. According to the FAD of N. waageni, the IOB is at the base of bed 25-2 of the West Pingdingshan Section in Chaohu, 42.19 m above the Permian-Triassic boundary, and it is slightly higher than the base of the Flemingites-Euflemingites Ammonoid Zone at the section. 相似文献
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