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171.
Brigitta Ammann 《Journal of Paleolimnology》1988,1(4):269-277
In the sediment of three Swiss lakes at a range of altitude from 514 to 2017 m, the Bölling and the Preboreal are recognized as two periods of rapid biotic changes. The main reason is rapid climatic change that triggered shifts in different groups of aquatic and terrestrial organisms. Although these groups would be expected to have very different response times, e.g., to increasing summer temperature, their assemblages responded with surprizing synchroneity. For extracting climatic signals from stratigraphies, the quickly responsive indicators like oxygen isotopes or beetles are useful. For understanding ecological dynamics under a changing climate, the comparison of biota with various response time are important.This is the sixth of a series of papers to be published by this journal that was presented in the paleolimnology sessions organized by R. B. Davis and H. Löffler for the XIIth Congress of the International Union for Quaternary Research (INQUA), which took place in Ottawa, Canada in August 1987. Drs. Davis and Löffler are serving as guest editors of this series. 相似文献
172.
A pre-Ipswichian cold stage mammalian fauna from the Balderton Sand and Gravel,Lincolnshire, England
The Balderton Sand and Gravel has yielded one of very few mammalian faunas dated to the penultimate Cold Stage in Britain. The assemblage is dominated by mammoth and woolly rhinoceros, with subordinate horse, red deer, bison, straight-tusked elephant, musk ox, reindeer, wolf, lion, brown bear and cf. narrow-nosed rhinoceros. This fauna indicates cold stage conditions, probably including one or more interstadial episodes. The presence of straight-tusked elephant and cf. narrow-nosed rhinoceros supports its pre-Devensian age, and provides corroboration for the occurrence of these taxa in the British Wolstonian. An attempt is made to analyse the fossil collection by preservation type and adhering sediment: the occurrence of individual species appears to be largely uncorrelated with lithology. The Balderton assemblage corresponds well to other British mammal faunas assigned to a cold interval between the Hoxnian and Ipswichian Interglacials. 相似文献
173.
The Bonarelli Horizon is an important regional marker level in the Umbria-Marche Apennines. It is characterized by consisting of black bituminous shales that yield a distinctive radiolarian fauna. Black shales referable to the Bonarelli Horizon are also present in the Southern Alps. The horizon is of uniform lithology and contains radiolarian assemblages of late Cenomanian-early Turonian age throughout both the Umbria-Marche Apennines and Southern Alps. Several new radiolarian taxa have been recognised and described from the Bonarelli Horizon of both areas. Two new species are defined in this paper, namelySethocapsa bossoensisandXitus picenus. 相似文献
174.
The stratigraphic and palaeoenvironmental implications of a section in the Upper Senonian to Lower Eocene carbonates of the Tripolitza Platform in central Crete are discussed in this paper. The lower part (upper Campanian–lower Maastrichtian) of the succession consists of about 75 m of thickly bedded, light to dark grey limestones, dolomitic limestones and dolomites that were deposited on an inner carbonate platform. It is characterized by stratified bioclastic rudist facies (shelly limestone) associated with foraminifera and especially with species of the Rhapydioninidae family. These are overlain by 35 m of crystalline light grey dolomites that were deposited on a very restricted internal platform, characterized by intertidal-supratidal facies. The overlying 75-m-thick light grey dolomitic limestones and dolomites are characterized by the presence ofRhapydionina liburnicaStache, and in the uppermost part byNeobalkhania bignotiCherchi, Radoicic & Schroeder, dating it as Late Maastrichtian. The facies, cryptalgal laminites with fenestrae of varying dimensions, suggest relatively extensive subaerial exposure. Possible pedogenic textures are common in this sequence and especially in the uppermost part, which coincides with the K/T boundary. The presence ofPseudonummoloculina heimi(Bonet) at two levels in the Maastrichtian succession suggests transportation of Middle-Late Cenomanian sediments from emergent blocks of the platform during this period. A gap is suspected, for regional stratigraphic reasons, between this horizon and the next which containsSpirolinasp. and “Pseudochrysalidina” sp., dating it as Early-Middle Eocene. 相似文献
175.
广西玉林早泥盆世早期腕足动物生物地层研究 总被引:1,自引:0,他引:1
在广西玉林樟木地区早泥盆世北均塘组、良合塘组、樟木组35属48种腕足动物演化和地层分布特征研究的基础上,建立了6个腕足动物生物带(自下而上):1.Quadrithyrinaexpansa-Prodavidsoniamirabilis带;2.Grayinamagnificaguangxiesis-Schizophoriasulcatina带;3.Reticulariopsiscostatus带;4.Grayinamagnificasinica带;5.Quadrithyrisrobusta-Boucotia带;6.Qrientospiriferwangi带。依据国际对比和与笔石的层位关系认为:第1-3带为晚洛赫柯夫期,并且1、2、3带很可能分别相当晚洛赫柯夫早、中、晚期;第4带为早布拉格早期;第5、6带分别相当中、晚布拉格期。 相似文献
176.
北喜马拉雅地区三叠纪地层划分 总被引:9,自引:1,他引:8
北喜马拉雅地区的三叠纪地层发育完整,层序清楚、构造简单、未变质,可分为土隆群、曲龙共巴组与德日荣组3个岩石地层单位,其中生物化石丰富,属典型的特提斯动物群。该地层主要出露于亚东、定结、定日、聂拉木土隆、普兰、札达马阳一带,呈东西向带状展布,在我国境内延伸达1500km以上,与印度库蒙(Kumaun)地区的三叠纪地层(由下而上为:Chocolateseries,Kala-paniLimestone,KutiShale,KiotoLimestone)可以进行对比。 相似文献
177.
台西南盆地和北港隆起的中生界及其沉积环境 总被引:28,自引:4,他引:28
我国南海海域广泛存在中生代沉积地层,在南海寻找中生界油气藏潜力极大。台西南盆地和北港隆起有数十口井钻遇中生界,经过详细生物地层学工作确定了下白垩统(阿普特阶和下阿尔必阶)和侏罗系(?)两套中生代地层,是迄今南海北部中生界地层研究最为深入的地区,可作为对比的样板。介绍了台西南盆地和台湾西部中生界的岩性、岩相和生物地层学特征,指出晚侏罗世(?)与早白垩世之间沉积环境发生了显著变化,台西南盆地由深海至半深海变为内陆,而北港隆起由内陆变为海陆交互和浅海环境。 相似文献
178.
179.
为了解老挝万象含盐盆地的形成与演化历史,在老挝万象平原钾镁盐矿勘查项目中,对该地区进行了区域地质调查。老挝万象地区的侏罗系为一套夹少量碳酸盐岩的红色陆源碎屑沉积,由上到下可划分为班辛黑组、南舍组、南立组;该地层的介形类分属Gomphocythere-Darwinula组合、Darwinula sarytirmenensi-Darwinula magnca组合,叶肢介属滇南古渔乡叶肢介动物群,腹足类具中侏罗世陆生动物群特征;本区侏罗系为一套以湖泊沉积为主的河湖相沉积,构成一个完整的Ⅲ级层序,可划分出低水位体系域、湖侵体系域、凝缩期沉积及高水位体系域。这3个组的岩石地层、生物地层及年代地层特征,可与我国滇西地区的漾江组、花开左组相对比。 相似文献
180.
The results of studying dinocysts in the Upper Cretaceous-Lower Paleogene succession of the Kaliningrad region are considered. Distinguished in the succession are seven biostratigraphic units in the rank of the Palaeohystrichophora infusorioides, Chatangiella vnigrii, Cerodinium diebelii, Alisocysta margarita, Deflandrea oebisfeldensis, Areosphaeridium diktyoplokum, and Rhombodinium perforatum beds and one Charlesdowniea clathrata angulosa Zone. The Lyubavas Formation has not been distinguished on the west of the Sambian Peninsula. Ages of the Sambia, Alka, and Prussian formations are verified. 相似文献