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1.
日本具有4个标志早白垩世的半咸水和淡水软体动物群组合:欧特里沃期—早巴列姆期的立川和菖蒲动物群组合,晚巴列姆期的濑林动物群组合和早阿普特期动物群组合。纯非海相下白垩统大量分布于日本东北部(本州岛北部)的部分地区,以及日本中部、西南部的内带。在日本东北部的部分地区以及日本西南部的外带(四国岛与本州岛中部),从巴列姆阶下部往上有一些海相地层夹在非海相层中,这为研究非海相动物群提供了准确的年代依据。生物组合之间在种一级水平上的区别,主要由环境的差异而引起。1)立川动物群组合(欧特里沃期—早巴列姆期),含有半咸水Hayamina naumanni组合和淡水Megasphaerioides okurodaniensis组合;手取群的Okurodani、Kuwajima和Izuki三个组内的淡水软体动物可与本动物组合相对比;2)菖蒲动物群组合(欧特里沃期—早巴列姆期),含有Eomiodon nipponicus组合;3)濑林动物群组合(晚巴列姆期),含有Costocyrena radiatostriata组合,可与手取群的Kitadani组和日本东北部关门群的Sengoku组以及Monomiyama组的淡水软体动物组合相对比;4)日比原动物群组合(早阿普特期),含有Costocyrena minor组合,关门群Wakamiya组的淡水软体动物可与本动物组合相对比。  相似文献   

2.
中国非海相白垩纪腹足类组合序列和分布   总被引:1,自引:1,他引:0  
中国白垩纪非海相腹足类可划分为4个组合:1)早白垩世凡兰吟期巴列姆期Probaicalia vitimensis-Ptychostylus-口盖化石Reesidella robusta组合;2)早白垩世阿普特期阿尔必期Bellamya clavilithiformis-Mesocoshliopa cretacea-Zaptychius costatus-Brotiopsis组合,由于环境的不同,这一组合可分为2个亚组合:Brotiopsis亚组合和Bellamya clavilithiformis-Mesocoshliopacretacea-Zaptychius costatus亚组合;3)晚白垩世科尼亚克期中马斯特里赫特晚期Mesolanistes nanxiongensis组合,由于产出的层位不同,这一组合又可分为2个亚组合,Mesolanistes ziziformis亚组合和Mesolanistes-nanxiongensis亚组合;4)晚白垩世马斯特里赫特期最晚期Palaeoancylusna nxiongensi组合。  相似文献   

3.
根据非海相与海相,特别是共同的海相和非海相软体动物化石的对比,并结合放射性同位素测年,中国东北黑龙江东部和辽宁西部,韩国东南部庆尚盆地,日本西南部内带岐阜县北部牧户/庄川地区和外带四国德岛和物部地区早白垩世地层得到了对比,产自这些地层的非海相软体动物的时代也因此受到了约束。著名的中国东北含煤地层龙爪沟和鸡西群,盛产热河生物群/动物群的热河群的时代均为欧特里沃期/巴列姆期阿普特期,它们的上覆地层桦山群和孙家湾组为阿尔必期。韩国西南部新洞群和除金洞组以外的河阳群为阿普特期阿尔必期,不整合于新洞群之下的卯谷组主要为欧特里沃期。日本西南部内带的牧户/庄川地区的手取群和外带德岛和物部地区的物部川群均为欧特里沃期阿尔必期。Cuniopsis kihongi,Nakamuranaia leei,Koreanaia cheongi和Trigonioides(Wakinoa)tetoriensis的时代为欧特里沃期早巴列姆期。Viviparus onogoensis,Unio ogamigoensis,Myrene(Mesocorbicular)tetoriensis及Tetoria(Tetoria)yokoyami为欧特里沃期阿普特期。Arguniella cf.quadrata,A.cf.ventricosa,Sphaerium(Sphaerium)anderssoni,Probaicalia vitimensis和Pr.gerassimovi为欧特里沃期/巴列姆期阿普特期。Nakamuranaia chingshanensis,Plicatounio(Plicatounio)multiplicatus,Sphaerium(Sphaerium)coreanicum和Micromelania?katoensis为阿普特期阿尔必期。Nippononaia sinensis,Nip.tetoriensis,Nip.ryosekiana和Trigo-nioides(Wakinoa)wakinoensis是阿普特期的标志。Trigonioides(Trigonioides)quadratus,T.(T.)heilongjiangensis,Plicatounio(Plicatounio)naktongensis,Unio longus与Sphaerium(Sphaerium)chintaoense为晚阿普特期阿尔必期或阿尔必期的标志化石。我国东北、韩国东南和日本西南部非海相,特别是淡水软体动物接近的相似性表明这三地区在早白垩世时相连,并处于同一水系。但是,在欧特里沃期阿尔必期期间,这一陆块的东部,即频临古太平洋的日本西南部的外带因地势低而多被海水覆盖,在牧户/庄川和黑龙江东部存有遭受海侵的浅而窄的海湾,凡兰吟期,特别是欧特里沃期/巴列姆期之前,中国东北韩国东南部日本西南部陆块为受造山运动引起的隆起和沉降活动影响的高低不平的高原,经受了广泛而长期的剥蚀。多数含有包括熔岩和凝灰岩在内的火山岩,并与北东北北东方向的断裂带近于平行分布的非海相白垩纪盆地直至欧特里沃期/早巴列期(有些地区可能稍早(凡兰吟期))(134~126Ma),即华北克拉通破坏的高峰期(130~120Ma)才形成。这一现象表明,这些盆地受断裂,特别是伴随有强烈火山喷发和时而局部海侵的沿着古太平洋西北缘和郯庐断裂带的构造运动的控制。  相似文献   

4.
中国东部晚中生代广布的陆相火山盆地沉积,由于海相生物化石的匮乏造成与层型地区对比的困难,长期以来该地层时代仅笼统被认为属于晚侏罗世-早白垩世。通过岩石组合、构造层和沉积构造环境的综合对比,确立闽西地区的兜岭群与闽东地区南园群、浙西建德群可以对比,构造不整合面代表区域上由挤压向拉张构造背景转化的相对等时界面。兜岭群的植物群Cupressinocladus --Brachyphyllum 组合可能与北方的Ruffordia --Onychiopsis 植物组合大体相当,叶肢介、介形类、腹足类和双壳类等化石与浙江早白垩世建德生物群、北方的热河生物群均可以对比,时代应为早白垩世欧特里夫期-阿普特期。  相似文献   

5.
亚洲非海相白垩系的三分性及其类三角蚌类的分带   总被引:4,自引:0,他引:4  
亚洲非海相白垩系广泛发育,星罗棋布,展布于日本、朝鲜、中国、老挝、泰国、新加坡、蒙古以及苏联的亚洲部分,显示出明显的区域性,别具一格,含有地方性的类三角蚌动物群(Trigonioidacean faunae)。此外产有其他双壳类、腹足类、介形类、叶肢介、昆虫、脊椎动物、植物、轮藻及孢粉等。类三角蚌动物群特征鲜明,演化较为迅速。早白垩世兴起,中白垩世繁盛,晚白垩世萧条,早第三纪到来之前,退出地史舞台。对于研究它所赋存的母岩,亚洲非海相白垩系,  相似文献   

6.
中国白垩纪叶肢介生物地层学   总被引:3,自引:0,他引:3  
叶肢介是一种淡水甲壳类动物,个体不大,一般在几毫米到两厘米之间,软体有点像虾,具有很多附肢,雌雄异体,外裹一对几丁质壳瓣,形似蚌壳,但不如后者的钙质壳那么厚实坚硬。叶肢介从泥盆纪开始出现,中生代时其演化中心从欧洲迁移到了东亚,白垩纪它们的分异和演化达到顶峰,到了新生代则进入衰亡阶段。叶肢介化石一般出现在陆相地层中,由于它数量多、演化快、分布广泛,近年来已成为中国和邻近地区中生代非海相生物地层划分和对比研究的重要手段之一。中国大陆白垩系主要是陆相沉积,按古地理和生物地理区系,早白垩世可以划分为西南湖群和东北、东南、西北两个大区,前者出现的是直线叶肢介(Orthestheria)动物群,后者则是东方叶肢介(Eosestheria)和延吉叶肢介(Yanjiestheria)动物群;晚白垩世在西南湖群出现的是华美叶肢介(Aglestheria)动物群,在东北松花湖水系出现的是真瘤模叶肢介(Euestherites)动物群,在华中和东南沿海云梦泽水系出现的是薄壳叶肢介(Tenuestheria)动物群。链叶肢介(Halysestheria)是联系它们相互对比的共同分子;晚白垩世早期的线叶肢介(Nemestheria)动物群则在上述3个区系都有分布,甚至在西北喀什地区的塞诺曼期海陆交互相沉积和美国德克萨斯州同期海相地层的陆相夹层中都有发现的记录,它是将中国陆相白垩系与国际海相标准划分联系起来的重要证据。关于中国白垩纪的叶肢介动物群和有关陆相地层的划分对比,产东方叶肢介的义县组以前放在上侏罗统顶部或做为侏罗系-白垩系过渡层处理,这次按全国地层表将东方叶肢介群归入早白垩世。  相似文献   

7.
孙革 《地质与资源》2022,31(3):289-302
中国东北地区东部白垩纪陆相地层发育,富含动、植物化石,并形成了重要的煤及油页岩等矿产.这里还保存了我国除西藏外唯一的早白垩世最早期海相地层的记录,对研究我国白垩纪古地理具有重要意义.近年来,这一地区在白垩纪地层古生物研究中有许多新发现,其中有些新发现还填补了东北地区某些地层"空白".本文简要介绍上述新发现并对这一地区晚白垩世植物群与以恐龙为代表的动物群的协同演化做初步探讨.  相似文献   

8.
黑龙江东部早白垩世生物地层学研究的主要进展   总被引:22,自引:0,他引:22  
沙金庚 《地学前缘》2002,9(3):95-101
巴列姆期的菊石、巴列姆期—阿尔必期的海相双壳类、早白垩世的沟鞭藻、放射虫和有孔虫等的发现 ,均证实了黑龙江东部含煤地层龙爪沟群、鸡西群和大架山组的时代为早白垩世中、晚期。鸡西群中含有热河或威替姆动物化石群中常见的双壳类化石 ,这一事实似乎暗示着中国热河或俄罗斯威替姆动物化石群为早白垩世时代。早白垩世 ,特别是巴列姆期—阿尔必期 ,沿大架山—云山—虎林-裴德—鸡西一线北东东方向存在着一条向东 (古太平洋 )开口 ,但由东向西变浅的狭长海湾。多次海侵和海泛沿着这一海湾由东向西至鸡西后向南和向北 ,并可能向西扩散。正是这一海湾和海平面的升降控制着东北地区的早白垩世的气候、地理、生物群落的演变、甚至煤的聚集和油的形成  相似文献   

9.
我国非海相白垩纪介形类化石可以划分为7个组合:1)分布于我国西北和西南地区欧特里沃期巴列姆期的Jingguella-Minheella-Pinnocypridea组合;2)分布于我国西北和西南地区巴列姆期的Cypridea-Latonia-Darwinula组合;3)阿普特期阿尔必期的Cypridea(Morinina)-Bisulcocypridea-Mongolocypris组合;4)分布于我国东北、中部及东部地区欧特里沃期巴列姆期的Cypridea-Mongolianella-Darwinula组合;5)分布于我国东北、中部及东部地区巴列姆期阿普特期的Cypridea(Cypridea)-Cypridea(Ulwellia)-Limnocypridea组合;6)塞诺曼期塞农期的Cypridea-Triangulicypris-Sunliavia-Lycopterocypris组合;7)坎潘期马斯特里赫特期的Talicypridea-Cypridea-Quadracypris-Candona组合。依据以上7个介形类化石组合,我国22个地区含介形类的73个地层单元(群/组)得到了对比。  相似文献   

10.
一般认为中国北方的燕辽地区(冀北和辽西)是热河生物群起源和演化的中心, 因此中国的大兴安岭北部和俄罗斯外贝加尔地区可视为热河生物群化石分布的北部区。大兴安岭北部一个新发现的化石点产热河生物群鱼群重要分子燕鲟属和中华弓鳍鱼属, 但这一地区还未发现四足动物化石。外贝加尔地区的Krasnyi Yar和Mogoito两个化石点产较丰富的早白垩世脊椎动物化石, 层位和时代分别为Khilok组(阿普特期), Murtoi组(晚巴列姆-中阿普特期)。与热河生物群其他分布区相比, 北部区和燕辽地区的脊椎动物群组成和古环境背景更为相似。  相似文献   

11.
The Lower Cretaceous ammonite fauna of Japan was influenced by the Tethyan, Boreal and North Pacific realms with their oceanic current patterns and ammonite distributions. The hypothesis of oceanic circulation can be utilized to interpret the existence of the “Bering Strait” and the changing position of the “Boreal front,” that is the contact region of warm and cold-water masses. To understand such a system fully, a comprehensive understanding of the geographical distribution of ammonite faunas is required. The occurrence of twenty-five ammonite species, belonging to twenty genera, is confirmed in the Barremian to Albian of Japan. Of these, 24 species are described in this paper, including Barremites macroumbilicus sp. nov. The fauna can be divided into three associations, lower, middle, and upper, indicating late Barremian, late Aptian, and late Albian of the European standard zonation. The faunal characters suggest that the habitats of these ammonite faunas may have changed during later Early Cretaceous, with faunas characterizing three different environments, i.e., nearshore, intermediate, and distal shelf to upper slope setting. Ammonites of the lower association (late Barremian) are related to those of the Tethys, Boreal European, and circum-Pacific regions, and suggest that the Early Cretaceous Katsuuragawa Basin was deposited under the influence of currents from both high latitude and equatorial areas. The occurrence of Crioceratites (Paracrioceras) suggests that the Boreal European elements, including Simbirskites and Crioceratites (Paracrioceras), transited between Northwest Europe and Japan through the Arctic Sea, indicating that the Pacific Ocean was connected with the Arctic Sea at that time. The second association (late Aptian) is composed of ammonites of the Tethyan and circum-Pacific regions. As European Boreal ammonite taxa are absent in this association, it is concluded that the Pacific Ocean probably was not connected with the Arctic Sea at the time. Consequently, the “Boreal Front,” marking the contact between warm and cold water masses, was located at mid-latitude in the “Bering Strait” region during Barremian and subsequently moved northward during Albian. The uppermost ammonite association (late Albian) also consists of Tethyan and circum-Pacific taxa. Desmoceras (Pseudouhligella) poronaicum expanded its range with northward and eastward circulation of oceanic currents, suggesting the current must have represented a warm water-mass from the equator. The species subsequently migrated from the southern Katsuuragawa Basin to the Hokkaido area during late to latest Albian.  相似文献   

12.
The first record of the superfamily Trigonioidoidea (Order: Unionoida) from the Lower Cretaceous of Teruel, Spain is described and compared to known taxa from Europe and Asia. This is a new record of the Trigonioidoidea from Europe, following material described from the Barremian of the Isle of Wight (southern England) and Aptian-Barremian from Iberian Range (Spain). The new material, recorded from the Albian of the Escucha Formation (“Barriada” Member) in Utrillas (Teruel, northeastern of Spain), comprises four specimens. Analysis of the main morphological characters including anterior musculature, dentition, and ornamentation indicates that this material constitutes a new genus and species, Iberanaia iberica. The palaeoenvironment in which the bivalves lived corresponds to a fluvial-palustral setting connected to a deltaic system.  相似文献   

13.
Site 549 recovered a Lower Cretaceous succession which has been shown to include parts of the Barremian and Albian stages. Forty-four species of Ostracoda are illustrated and their stratigraphic distribution used to recognise three major facies units. An high diversity inner shelf facies earlier in the Barremian gives way to a low diversity, outer shelf facies, higher in the succession. The early Albian appears to indicate a return to an inner shelf fauna. The faunas recovered have been compared to similar faunas elsewhere in N. W. Europe.  相似文献   

14.
The spotty nature of the terrestrial fossil record for the Mesozoic hinders a more complete understanding of dinosaur diversity. For stegosaurs (Ornithischia), the plated dinosaurs, only a few and fragmentary remains are reported from the Early Cretaceous of Europe. A recent revision concluded that only a partial vertebra of the nomen dubium Craterosaurus (?Aptian, England) could be considered as stegosaurian. Here we report on a stegosaur tooth from the Early Cretaceous (Berriasian) Purbeckian deposits of Cherves-de-Cognac (Charente), southwestern France. This tiny tooth was examined in detail using microtomography. Comparisons being limited by the rarity of stegosaur tooth rows material (e.g., from the skull of the holotype of Stegosaurus stenops) and dental material, notably from Europe, we observed new material of cf. Stegosaurus armatus and Hesperosaurus mjosi from the Upper Jurassic Morrison Formation of Wyoming (USA). The tooth shows the most similarities to the Late Jurassic genera Stegosaurus and Hesperosaurus, but differs in having a distinctive downwardly arched (V-shaped) cingulum on the ?lingual face (maxillary tooth hypothesis). It is referred to as Stegosauria indeterminate, a medium-sized quadrupedal herbivore that inhabited an emerged land between the Armorican Massif and the Massif Central. This finding is the first evidence of a stegosaur from the Early Cretaceous of France and a welcome addition to the meagre European record of that time. In addition, it is the second stegosaurian tooth crown reported from Europe. The assemblage of ornithischians of Cherves-de-Cognac shares some similarities with that of the Early Cretaceous (Berriasian) of the Purbeck Limestone Group, southern England. The relative rarity of ornithischian osteological remains in both Purbeckian environments suggests that most of these dinosaurs were mainly inhabitants of inland terrestrial palaeoenvironments.  相似文献   

15.
16.
姬书安  张培 《地球学报》2022,43(1):1-10
广西壮族自治区扶绥县那派盆地早白垩世新隆组中产有包含蜥脚类、兽脚类、鸟脚类、疑似鹦鹉嘴龙类的恐龙动物群,但鸟脚类的属种鉴定尚不能进一步确认.最近发现于那派盆地新的鸟脚类肠骨、坐骨化石材料,显示出基干禽龙类的典型形态,其特征又不同于该类群其他已知属种,应代表禽龙类一新属新种,被命名为广西那派龙Napaisaurus gu...  相似文献   

17.
New fossils of dinosaurs and pterosaurs have been found in the conglomeratic facies of the Maungataniwha Member of the Tahora Formation (Campanian) of New Zealand. These derive from a large theropod, a sauropod, an ankylosaur and a pterosaur. Together with previously described material they indicate at least five, maybe seven, taxa from the Late Cretaceous terrestrial fauna of New Zealand. At that time New Zealand was an island near Antarctica, so this represents an insular, polar fauna.We assume a vicariance model for the origin of this fauna, which probably samples that present in Antarctica at the time New Zealand rifted away from it. The fauna differs from other well known Cretaceous Gondwana faunas in including an ankylosaur, but is similar to that from the Late Early Cretaceous of Queensland, Australia. The inclusion of both an ankylosaur and sauropod lend a relict, Early Cretaceous aspect to the fauna. There seems to be no particular similarity to known polar faunas from the Early Cretaceous of Victoria, Australia, or the Late Cretaceous of Alaska and Antarctica.Dinosaurs, both large and small, were capable of surviving in the cool to cold-temperate, seasonal climate of New Zealand at this time.  相似文献   

18.
The earliest Aptian marine transgression of the Lower Cretaceous across southern England resulted in the collapse of the generally freshwater Barremian environment and the initiation of marine mileux. Salinities passed from fresh-oligohaline to meso- and pliohaline, reaching fully marine conditions during the obsoletum Subzone (P. fissicostus Zone). Newly formed environmental niches were rapidly occupied by ostracod associations. In the Isle of Wight, freshwater Cypridea-rich assemblages in the lower Shepherd's Chine Member (Vectis Formation) were gradually replaced by faunas dominated by Sternbergella cornigera, Mantelliana mantelli and Theriosynoecum fittoni. Marine taxa recorded from the Atherfield Clay Formation migrated predominantly from the Paris Basin and include Asciocythere albae, Schuleridea derooi, Neocythere gottisi, N. bordeti, Cythereis geometrica, Cytheropteron stchepinskyi and Protocythere croutesensis.  相似文献   

19.
Late Cretaceous sedimentary history has been strongly influenced by both sea-level fluctuations and inversion tectonics. Evidence for tectonic movements, originally identified in German Late Cretaceous basins, is applied to the UK successions. Two periods of movement are conspicuous: a Middle Turonian episode involving huge loss of section along anticlinal axes in southern England and a Late Santonian-Early Campanian episode also involving section loss on structure and section gain off structure. This pattern is repeated where folds or blocks are underlain by inversion thrust faults (e.g. the Purbeck Fault in Dorset, the Falmer Fault in Sussex, the Portsdown Fault in Hampshire and the Bray Fault in Upper Normandy). Other episodes of inversion in the Late Turonian to Middle Coniacian and the late Early Campanian are investigated and are a probable cause of slump beds and slides. These tecto-sedimentary episodes can be applied to structures in Northern Ireland, Inner Hebrides, North Sea and Yorkshire as well as southern Britain. Beyond NW Europe the Late Santonian – Early Campanian event is widely recognised in the Carpathians, southern Europe, Africa and the Levant and coincides with the end of the Long Cretaceous Quiet Zone (Chron 34N to 33R) perhaps representing a major change in Earth dynamics related to Mid-Ocean Ridge crustal production and intra-continental crust tectonism.  相似文献   

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