Late Permian-Early Triassic Conodont Biofacies and Bioprdvinces in South China and Himalaya1     

Yao  Li  Zhan Jianxin Zishun Lipei  Hao Weicheng 《《地质学报》英文版》1994,7(2):209-218

Abstract On the basis of existing conodont data, the authors have studied the Late Permian-Early Triassic cohodonts of different farms and biofacies in detail Five conodont biofacies are recognised, from shallow to deep water: 1. Hindeodus conodont biofacies 2. Pachycladina-Parachi rognathus conodont biofacies, 3. Gondolella-Hindeodus Conodont biofacies, 4. Gondolella - Neospathodus conodont biofacies, and 5. Xaniognathus cohodont biofacies. Considering the temporal and spatial changes of these conodont biofacies, 3 conodont bioprovinces have been divided. In light of the biofacies changes of each bioprovince, the authors also discuss, in this paper, the regularity of transgression-regression cycles of eastern Tethys and their possible relation to the mass biotic alternation.  相似文献   

塔里木盆地奥陶系牙形石带及沉积层序   总被引：12，自引：0，他引：12  

赵宗举  赵治信  黄智斌 《地层学杂志》2006,30(3):193-203

通过对塔里木盆地西部柯坪、巴楚及东部却尔却克奥陶系露头剖面及盆地覆盖区钻井岩心的大量牙形石样品分析,分别建立了塔里木盆地中西部及东部地区奥陶系牙形石带序列。盆地中西部地区牙形石带共计22个,由老到新分别为Variabiloconusaff.bassleri带、Rossodusmanitouensis-Cordylodusrotundatus-Chosonodinaherfurthi组合带、Scolopodusquadraplicatus带、Glyptoconusfloweri带、Tripodusproteus/Paltodusdeltifer带、Glyptoconusunicostatus带、Serratognathusdiversus/Paroistodusproteus带、Serratognathoideschuxianensis-Scolopoduseuspinus-Erraticodontarimensis组合带、Aurilobodusleptosomatus-Loxodusdissectus组合带、Amorphognathusvariabilis带、Eoplacognathussuecicus带、Pygodusserrus带、Pygodusanserinus带、Eoplacognathusjianyeensis/Baltoniodusva-riabilis带、Eoplacognathuselongatus带、Baltoniodusalobatus带、Belodinacompressa/Periodongrandis带、Phrag-modusundatus带、Belodinaconfluens带、Yaoxianognathusneimengguensis带、Yaoxianognathusyaoxianensis带和Aphelognathuspyramidalis带;盆地东部地区下奥陶统属于深水盆地相,其特有的牙形石带主要有5个,由老到新分别为Cordyloduslindstromi带、Cordylodusangulatus带、Prioniodusgilberti带、Paroistodusproteus带和Prionio-duselegans带。同时初步建立了塔里木盆地奥陶系三级层序地层格架,并探讨了上述牙形石带与盆地奥陶系主要构造单元岩石地层单位以及全盆地可对比的6个三级层序之间的关系。  相似文献   

安徽巢湖平顶山西坡剖面印度阶与奥伦尼克阶界线层高分辨率牙形石生物地层     

赵来时  童金南  孙知明  常德峰  张克信  张素新 《地球科学》2007,32(3):291-302

下三叠统印度阶与奥伦尼克阶全球候选层型剖面之一的中国安徽省巢湖市平顶山西坡剖面界线层,经连续不间断采样获得大量牙形石化石并进行详细的分带工作,建立了该界线层牙形石生物地层.由下往上划分为:1.Neospathodus dieneri带;2.N.waageni带.前者依次分为3个亚带:N.dieneri Morphotype1亚带,N.dieneri Morphotype2亚带和N.dieneri Morphotype3亚带.牙形石带可与该界线层的菊石带进行很好的对比;在详细区分牙形石Neospathodus属内各种特征的基础上,结合地层分布情况,跨越印度阶与奥伦尼克阶界线,演化谱系十分明显,牙形石N.dieneri Morphotype3在奥伦尼克阶之底即Smithian初期演化为:N.dieneri Morphotype3→N.waageni→N.pingdingshanensis、Neos-pathodus dieneri Morphotype3→N.waageni(细齿直立型)→N.n.sp.R和Neospathodus dieneri Morphotype3→N.pakistanensis.从谱系演化的观点出发认为:N.waageni的首现点作为奥伦尼克阶底界是合理的,并在该剖面确定了印度阶与奥伦尼克阶界线位于第24-16层,距剖面大隆组与殷坑组界线40.49m处.  相似文献   

西藏西部狮泉河地区二叠纪和三叠纪牙形石的发现及其意义   总被引：2，自引：3，他引：2  

纪占胜姚建新  武桂春 《地质通报》2007,26(4):383-397

西藏西部阿里狮泉河地区的昂杰组、下拉组和左左组中发现牙形石化石。昂杰组的牙形石组合大致对比于中二叠世空谷期早中期Mesogondolella idahoensis-Vjalovognathus shindyensis组合带。下拉组顶部的牙形石组合大致对比于晚二叠世长兴期晚期Clarkina changxingensis带。左左组中含有早三叠世的Neospathodus sp.和Gladigondolella sp.,左左组和下拉组整合接触,左左组主体时代为三叠纪。狮泉河地区在早二叠世末期就开始由冈瓦纳相碎屑岩沉积转变为特提斯相碳酸盐岩沉积,在晚二叠世长兴期和早三叠世依然维持在海相沉积环境中。冈底斯西部在晚二叠世和三叠纪为古陆的观点有待于重新审视。  相似文献   

全球奥陶系底界的“金钉子”问题及我国特马豆克阶(Tremadocian)的划分与对比          下载免费PDF全文

汪啸风  STOUGE Svend  MALETZ Jorg  王传尚  阎春波 《中国地质调查》2015,2(5):14-26

对全球寒武系与奥陶系界线层型剖面和点位(GSSP)——西纽芬兰绿岬(Green Point)剖面和我国吉林白山(原浑江)大阳岔小洋桥原全球寒武系与奥陶系界线候选剖面的对比研究表明,绿岬"金钉子"剖面所指定的界线生物标志——波动古大西洋牙形石(Iapetognathus fluctivagus)并不存在于所指定的界线生物层和点位上,而且在分布和分类上是均存在争议的物种,更遗憾的是,所展示的大部分牙形石和笔石标本图片以及碳氧同位素异常数据也并非来自该"金钉子"剖面,因而完全违背了选择金钉子剖面的原则和要求,有必要进行重新的评估。小洋桥寒武系与奥陶系界线剖面交通方便、环境优美,寒武系与奥陶系界线地层系由一套深水且未变质的黑色、黄绿色页岩与灰色薄层瘤状灰岩所构成的韵律沉积组成,并保存了完整的具有广泛代表性牙形石和笔石序列,在详细研究的34 m界线间隔中,自下而上保存了完整的Cambrostodus、Codylodus proavus、C.intermedius、C.lindstromi和C.angulatus等5牙形石生物带,在C.intermedius带上部至C.angulatus带之间,还依次出现3层笔石,归属于重新厘定的Rhabdinopora parabola和Anisograptus matanensis等2个笔石带,此外还有大量三叶虫和介形类化石共生,结合高精度同位素地球化学的研究,笔者等建议,以全球广泛分布的牙形石C.intermedius的首现,取代Iapetognathus fluctivagus,作为寒武系与奥陶系界线划分对比的标志,其层位与原来所指定的界线层几乎一致或接近,界线之上所记录的最大碳同位素异常和首次出现的最早的浮游正笔石——R.parabola(含R.praeparabola),可作为该界线划分的辅助标志。  相似文献   

晚泥盆世牙形刺及软骨鱼类在西准噶尔塔克台组中的发现及意义   总被引：2，自引：0，他引：2       下载免费PDF全文

王志宏  纵瑞文  龚一鸣  王成源 《地球科学》2015,40(3):588-596

新疆西准噶尔哈拉也门地区原有一套地层划分为下石炭统和布克河组,岩性组合与标准剖面差异较大,因此,新建塔克台组.在该组参考剖面TK01第3层含化石的灰岩透镜体中,发现了少量非常重要的浅水相牙形刺,包括3属6种1未定种:Icriodus alternatus alternatus、Icriodus cornutus、Icriodus expansus、Polygnathus krestovnikovi、Polygnathus procerus、Polygnathus makhlinae、Ancyrognathus sp.,与这些牙形刺共生的还有软骨鱼类化石Protacrodus sp.和Phoebodus sp..该化石组合表明,新建的塔克台组的时代为晚泥盆世法门期早期.   相似文献   

三峡地区寒武纪-三叠纪古海水Sm/Nd变化特征:来自牙形石的证据     

周炼  陈孝红  李志宏  刘勇胜  张利 《地球科学》2006,31(1):136-142

牙形石作为划分地层的标准化石, 具有确切的地层层位和较高的REE含量, 并不容易受成岩作用的影响, 因此作为研究古海水演化的指示剂引起人们的广泛关注.利用同位素稀释法对扬子克拉通三峡地区寒武纪—三叠纪海相碳酸盐岩中代表古海水化学组成牙形石的Sm/Nd比值进行测定, Sm/Nd比值在0.108-0.348之间, 有较大的变化范围.建立Sm/Nd比值随时间的演化曲线, 并结合已有沉积地层学和沉积地球化学的成果进行研究, 结果表明, 古海水Sm/Nd比值变化与海平面升降、古陆块的隆起有明显对应关系, 同时, 区域性构造运动, 如海底地壳拉张产生的幔源组分和地幔柱活动也会影响古海水的Sm/Nd比值.因此, 古海水的Sm/Nd比值对海平面的升降、古大陆的风化作用和区域构造事件有指示意义.   相似文献   

Late Changhsingian radiolarian biostratigraphy from Guangxi,South China and its correlation to conodonts   总被引：2，自引：0，他引：2  

Jun Wu  QingLai Feng 《中国科学D辑(英文版)》2008,51(11):1601-1610

A well-preserved, abundant radiolarian fauna was obtained from three sections: the Dongpan, Liuqiao, and Paibi sections, in southern Guangxi, South China. Sixteen species belonging to Albaillella and Neoalbaillella, including seven undetermined species, are recognized. On the basis of stratigraphic distribution of these species, two radiolarian zones, the Albaillella triangularis Zone and the Albaillella yaoi Zone, are established. The correlation between radiolarian zones and conodont zones is suggested based on the discovery of coexisting conodonts. Albaillella triangularis and Albaillella yaoi zones correspond to Neogondolella postwangi and Neogondolella yini zones respectively.  相似文献   

End-Permian conodont fauna from Dongpan section: Correlation between the deep-and shallow-water facies   总被引：1，自引：1，他引：0  

GenMing Luo  XuLong Lai  QingLai Feng  HaiShui Jiang  Paul Wignall  KeXin Zhang  YaDong Sun  Jun Wu 《中国科学D辑(英文版)》2008,51(11):1611-1622

This paper systematically investigated the conodonts from the uppermost Permian to the Lower Triassic at the Dongpan Section, Southern Guangxi, South China, and obtained abundant Late Permian conodonts from the syndepositional limestone lenses of beds 3 and 5-2 at this section. One genus and eight species of conodont P1 element including one new species, Neogondolella dongpanensis sp. nov., have been identified. The feature of conodont fauna indicates that conodonts collected from beds 3 and 5 at the Dongpan Section belong to the Neogondolella yini conodont zone, and correspond to bed 24 at the Meishan Section. Based on these conodont data, we suggest that the Neoalbaillella optima radiolarian zone at the Dongpan Section at least extended to the upper part of the N. yini conodont zone.  相似文献   

Early Silurian positive δ13C excursions and their relationship to glaciations,sea‐level changes and extinction events     

David K. Loydell 《Geological Journal》2007,42(5):531-546

Evidence is presented from the upper Aeronian, lower Sheinwoodian and middle Homerian demonstrating that positive δ¹³C excursions in the lower Silurian are the result of increased carbonate weathering and probably also enhanced burial of organic carbon coincident with sea‐level falls resulting from growth of ice sheets on the South American part of Gondwana. Graptolite extinctions are coincident with the δ¹³C excursions, whereas major conodont extinction events (Ireviken and Mulde) are not, but conversely, occur at times of high sea level. This suggests very different controls on graptolite and conodont global diversity patterns. Palynological studies suggest that netromorph acritarchs may have been opportunists that flourished during positive δ¹³C excursion intervals. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献