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1.
Radiolarian data provide important age constraints on the development of terranes within the New England orogen and have implications for existing tectonic models. Most radiolarian assemblages recovered from the orogen are of Late Devonian to Early Carboniferous ages. Albaillellaria comprise a minor proportion of the faunas present but have major biostratigraphic significance.Holoeciscus Foreman,Helenifore Nazarov and Ormiston,Circulaforma Cheng,Ceratoikiscum Deflandre,Protoalbaillella Cheng, andAlbaillella Deflandre, two new genera and three new species are found at various stratigraphic levels. Eleven radiolarian assemblages are recognised. In stratigraphic order these are theHelenifore laticlavium-Ceratoikiscum planistellare, Protoholoeciscus hindea, Holoeciscus formanae, Paraholoeciscus bingaraensis,Ceratoikiscum umbraculum, Protoalbaillella anaiwanensis, Albaillella paradoxa, Albaillella undulata-Albaillella indensis,Albaillella indensis-Albaillella furcata, Albaillella cartalla-Albaillella thomasi andCirculaforma omicron assemblages. There is an apparent biostratigraphic succession amongst the Albaillellaria in the New England orogen in whichProtoholoeciscus hindea n. gen. n. sp. is transitional betweenCeratoikiscum Deflandre andHoloeciscus Foreman andParaholoeciscus bingaraensis n. gen. n. sp. is transitional betweenHoloeciscus Foreman and theAlbaillella paradoxa Deflandre group.  相似文献   

2.
南莫溪结合带位于老挝北部万象地区,是黎府缝合带的重要组成部分。本文结合区域地质调查开展剖面工作,采集了硅质岩样品进行放射虫化石鉴定,共鉴定出放射虫9属29种,包括中–晚泥盆世放射虫Radiobisphaera rozanovi,Trilonchevetusta和晚泥盆世放射虫Heleniforerobustum,以及晚泥盆世放射虫属种Triloncheminax (Hinde)等。建立了中–晚泥盆世Radiobisphaera rozanovi-Stigmosphaerostylus pusilla组合带、晚泥盆世Trilonche minax延限带和早石炭世Albaillella paradoxa-Archocyrtium riedeli组合带,探讨了南莫溪结合带的构造古地理特征。该成果进一步丰富了老挝北部黎府缝合带的古生物化石组成特征,对研究南莫溪结合带的演化历史具有重要的指示意义。  相似文献   

3.
Moderately well-preserved radiolarian assemblages are described from bedded cherts south of Mae Hong Son, north-west Thailand. Twenty species and subspecies are identified, including one new species ( Archocyrtium sashidai Feng sp. nov.). The assemblages belong to the middle Early Carboniferous Albaillella indensis and Eostylodictya rota zones. The new data suggest that there was a pelagic basin between the Shan-Thai terrane and Gondwana during the Early Carboniferous. This implies, contrary to previous interpretations, that the Shan-Thai terrane had already rifted apart from Gondwana during the Early Carboniferous.  相似文献   

4.
Well-preserved radiolarians were recovered from seven sections in the Mae Hong Son-Mae Sariang area, northwestern Thailand. 51 species assigned to 34 genera are identified, including 1 new species (Triassospongosphaera erici Feng sp. nov.) and 19 unidentified species. They are divided into the Late Permian, late Ladinian and middle Carnian radiolarian assemblages. Newly identified radiolarian assemblages, together with the published radiolarian biostratigraphic data from this region, indicate that there was a pelagic basin during the Late Paleozoic and Triassic. This basin was joined to the Chiang Dao and Changning-Menglian oceanic basins, and they represent the main oceanic basin of the Paleotethyan Archipelago Ocean. This main oceanic basin was situated in the traditional “Shan-Thai Block”. Therefore, “the Shan-Thai Block” was not a single block during that stage, but composed of the Paleotethyan Ocean and two continental terranes that were affiliated with the Gondwana and Cathaysian domains, respectively.  相似文献   

5.
《Comptes Rendus Palevol》2016,15(5):453-459
Radiolarians are usually abundant in chert sequences and they have thus been widely used for the biostratigraphy of deep-water sediments. However, there are many difficulties in the correlation of radiolarian biostratigraphic schemes with the standard conodont zones. In this study, 21 radiolarian species were extracted from the Gufeng Formation that crops out in the Luojiaba (LJB) section (western Hubei, China), together with 5 co-occurring conodont species. In this way, it is the first time that the Pseudoalbaillella globosa, Follicucullus monacanthus and F. scholasticus radiolarian zones can be directly correlated with the Jinogondolella nankingensis gracilis, J. aserrata and J. postserrata conodont zones. Accordingly, the 3 radiolarians zones are now firmly correlated with the Roadian to middle Capitanian interval (Middle Permian).  相似文献   

6.
云南哀牢山缝合带由于长期未找到晚石炭世至二叠纪深海环境的化石及沉积地层记录,对哀牢山古特提斯盆地演化历史存在着不同认识。文中报道了采自云南墨江坝留地区上三叠统歪古村组底砾岩中的早石炭世和中二叠世放射虫化石,所有放射虫化石发现于4件燧石质砾石中,共计11属9种和7未定种及1属种未定放射虫。其中,3件砾石含有Albaillella deflandrei Gourmelon,Albaillella sinuosa Won and Seo等早石炭世放射虫化石组合,另1件砾石含有Pseudoalbaillella spp.,Quadricaulis scalae Caridroit and De Wever,Cauletella sp.和Ishigaum sp.等中二叠世放射虫化石组合。由此表明,哀牢山缝合带存在着早石炭世和中二叠世深海盆地沉积地层记录,哀牢山深海盆地应该在中二叠世之后封闭。该成果为探讨哀牢山古特提斯盆地演化提供了放射虫古生物学证据,进而说明哀牢山缝合带与金沙江缝合带一样,也存在石炭纪和二叠纪深水洋盆沉积地层记录,指示其演化历史是相同的。  相似文献   

7.
A shortage of Cenozoic vertebrate fossils in the Tibetan Plateau has been an obstacle in our understanding of biological evolution in response to changes in tectonism, topography, and environment. This is especially true for Paleogene records, so far known by only two sites along the northern rim of the Plateau. We report a Hongyazi Basin in northern Tibetan Plateau that produces at least three mammalian faunas that span Oligocene through late Miocene. Located at the foothills of the Danghe Nanshan and presently connected to the northern margin of the Suganhu Basin through the Greater Haltang River, the intermountain basin is controlled by the tectonics of the Danghe Nanshan to the north and Chahan’ebotu Mountain to the south, making the basin sediments well suited for inferring the evolutionary history of these two mountain ranges. At the bottom of the local section, the Oligocene Haltang Fauna is best compared to the early Oligocene Desmatolagus-Karakoromys decessus assemblage in the Dingdanggou Fauna in Tabenbuluk Basin. The Middle Miocene Ebotu Fauna from the middle Hongyazi section shares many taxa with the late Middle Miocene Tunggur mammal assemblage in Inner Mongolia, such as Heterosminthus orientalis, Megacricetodon sinensis, Democricetodon lindsayi, and Alloptox gobiensis. Toward the top of the section, the Hongyazi Fauna includes late Miocene elements typical of Hipparion faunas of North China. All three faunas are of typical North China-Central Asian characteristics, suggesting a lack of geographic barriers for faunal differentiation through the late Miocene. Sedimentary packages producing these faunas are arrayed from north to south in progressively younger strata, consistent with a compressive regime to accommodate shortening between Danghe Nanshan and Chahan’ebotu Mountain by thrust faults and folds. With additional constraints from vertebrate fossils along the northern flanks of the Danghe Nanshan, an eastward propagation of the Danghe Nanshan is postulated.  相似文献   

8.
Guadalupian–Lopingian sedimentary rocks are widely distributed in accretionary complexes in Japan, but the Guadalupian–Lopingian boundary (G–LB) is not well documented from these pelagic sediments. To identify the G–LB and to better correlate an extinction event that occurred around the Guadalupian–Lopingian boundary, we examined the conodont biostratigraphy from a Permian pelagic chert sequence in the Gujo-hachiman section, Gifu, southwest Japan. Age-diagnostic conodonts, including Clarkina postbitteri postbitteri, were found in this section. The biostratigraphic occurrences of these age-diagnostic conodonts can pinpoint the “G–L transitional zone” in the Gujo-hachiman section by comparison with well-studied sections from south China, including the GSSP section. The transitional zone was recognized by the first occurrence horizons of both Clarkina postbitteri hongshuiensis and C. p. postbitteri. The G–LB has been placed at or above the first occurrence horizon of the radiolarians Albaillella yamakitai or Albaillella cavitata in previous studies from China and Japan. We detected the first occurrence horizon of A. yamakitai below the base of the “G–L transitional zone,” in the Upper Capitanian. The conodont biostratigraphy is consistent with the radiolarian biostratigraphy in this section, which can be correlated to relevant sections in China.  相似文献   

9.
Famennian tabulate corals were very rare worldwide, and their biodiversity was relatively low. Here we report a unique tabulate fauna from the mid- and late Famennian of the western part of the Holy Cross Mountains (Kowala and Ostrówka), Poland. We describe eight species (four of them new, namely ?Michelinia vinni sp. nov., Thamnoptychia mistiaeni sp. nov., Syringopora kowalensis sp. nov. and Syringopora hilarowiczi sp. nov.); the whole fauna consists of ten species (two others described in previous papers). These corals form two assemblages—the lower, mid-Famennian with Thamnoptychia and the upper, late Famennian with representatives of genera ?Michelinia, Favosites, Syringopora and ?Yavorskia. The Famennian tabulates from Kowala represent the richest Famennian assemblage appearing after the F/F crisis (these faunas appear some 10 Ma after the extinction event). Corals described here most probably inhabited deeper water settings, near the limit between euphotic and disphotic zones or slightly above. At generic level, these faunas show similarities to other Devonian and Carboniferous faunas, which might suggest their ancestry to at least several Carboniferous lineages. Tabulate faunas described here represent new recruits (the basin of the Holy Cross mountains was not a refuge during the F/F crisis) and have no direct evolutionary linkage to Frasnian faunas from Kowala. The colonization of the seafloor took place in two separate steps: first was monospecific assemblage of Thamnoptychia, and later came the diversified Favosites-Syringopora-Michelinia fauna.  相似文献   

10.
From siliceous shales (Lower Carboniferous, Rheinisches Schiefergebirge), in direct neighborhood to a bed of allodapic limestone, the following fluontized radiolarian fauna has been extracted by chemical transformation of originally calcified skeletons:Albaillella cartalla, Latentifistula turgida, Eostylodktya cf. eccentrica, Tetragregnon sycamorensis sycamorensis, Belowea variabilis, Callela? hexactinia, Entactinia tortispina and Entactinia variospina. The limestone bed has been dated by calcareous foraminifera as being mid Visean in age (V 2b-3a, Cf 5-foraminiferal zone). The diagenetic calcification took place after the selective dissolution of the skeletons and was in itself not selective.  相似文献   

11.
Detailed micropaleontological investigation has established the distribution of major radiolarian assemblages in the Early to Middle Pliocene deep-sea sediments of the Antarctic region, with particular emphasis on the Gilbert Reversed Magnetic Epoch (t = 5.18 to 3.32 m.y. B.P.). Inter-core correlations, based on paleomagnetic stratigraphy and detailed radiolarian biostratigraphy, has provided a chronological framework for a detailed paleoclimatic investigation of the Gilbert Epoch. Early Gilbert sediments (t = 5.18 to 4.6 m.y. B.P.) contain a warm-Subantarctic assemblage marked by the presence of Anthocyrtidium ehrenbergi, “Eucyrtidium” spp., Carpocanium sp., Stylatractus universus and several collosphaerid species. Sediments of middle Gilbert age (t = 4.6 to 3.7 m.y. B.P.) contain a cool-Subantarctic assemblage marked by the presence of Stylodicta validispina, Cenosphaera cristata, Antarctissa longa, Triceraspyris pacifica and Lychnocanium grande rugosum. The late Gilbert—early Gauss sediments (t = 3.7 to 3.0 m.y. B.P.) contain an Antarctic assemblage marked by the presence of Antarctissa strelkovi, Antarctissa denticulata, Helotholus vema, Demospyris spongiosa and Eucyrtidium calvertense. The transition from a warm to a cold assemblage suggests a climatic deterioration occurring over a period of 1.6 m.y., significantly longer than the rapid climatic oscillations of the Pleistocene. Factor curves, produced by subjecting total faunal data to multivariate statistical analysis, have been interpreted in terms of paleoclimatic controls, resulting in a relative paleotemperature curve for the entire Gilbert Epoch. The maximum abundances of the Antarctic assemblage in the Gilbert and Gauss occurs between 3.7 and 3.2 m.y. ago coinciding closely with the 3.5 m.y. age of the first reported Patagonian glaciation in southernmost South America.  相似文献   

12.
《Geobios》2016,49(5):395-405
Geological explorations of the basal beds of the Río Yuca Formation (Tucupido region, Portuguesa State, western Venezuela) resulted in the recognition of a new vertebrate assemblage that includes eight taxa: the toxodont cf. Adinotherium, a Peltephilidae armadillo, the freshwaters fishes Platysilurus and Phractocephalus, the caiman Purussaurus, an indeterminate dolphin, turtles, and the previously recognized sloth Pseudoprepotherium venezuelanum. When compared with the higher latitudes faunas of Argentina and Chile, the presence of cf. Adinotherium and peltephilids in the Rio Yuca Formation is consistent, but not conclusive, with a Santacrucian to Frisian SALMA age. The associated fauna, as well recent apatite fission track analysis, indicates that the Río Yuca assemblage is more likely younger in age, specifically Middle to Late Miocene. So far, the Miocene localities of the northern part of South America have provided a less prolific fossil record compared to the southern part of the continent (e.g., Santacrucian and Friasian faunas of Patagonia), but the present work documents the surprising occurrence of two taxa (Peltephilidae and Nesodontinae) common in southern high latitude faunas of South America, implying the persistence of the Santacrucian-Friasian genus Adinotherium in younger strata from northern South America, and that peltephilids were much more widespread during the Miocene than previously recognized. The presence of these common Patagonian taxa (Peltephilidae and Nesodontinae) in Río Yuca also supports the hypothesis of prior researchers for the existence of biogeographical connections between the northern and southern portions of South America during the Late Oligocene or Early Miocene, which facilitated faunal interchange between the two regions. Finally, the biogeographical affinities of the freshwater fishes and the giant caiman (Purussaurus) indicate close relationships of the Tucupido region with the ancestral distribution of the Orinocoan–Amazonian drainage system.  相似文献   

13.
《Palaeoworld》2016,25(4):569-580
The glaciomarine sediments related to the Late Paleozoic Ice Age (LPIA) have an excellent stratigraphic record in Argentina, particularly those associated to the Late Carboniferous glacial episode identified along the southwestern margin of South America: Bolivia (Tarija Basin), west central Argentina (Calingasta-Uspallata Basin) and Patagonia (Tepuel-Genoa basins). The aim of this contribution is mainly a biostratigraphy update of the carboniferous brachiopod faunas that occur in the earliest postglacial interval (late Serpukhovian–Bashkirian) in the west central Argentina (i.e., Levipustula and Aseptella-Tuberculatella/Rhipidomella-Micraphelia faunas) and its regional correlation with those equivalents in the nearby basins. Components of these faunas are recognized from the Bolivia to Argentine Patagonia and their compositional variations appear to be controlled principally by a paleolatitudinal factor. The affinities showed by the postglacial faunas of the Calingasta-Uspallata Basin and the faunal assemblages that integrate the Lanipustula and Tuberculatella biozones in Patagonia differ from the significant contrast proposed by other authors, based on the paleogeographical position of Patagonia in the Late Paleozoic. Paleoecological studies focused on the paleoenvironmental controls related with the glacial dynamic are suggested to understand the complex relationship between these postglacial faunas.  相似文献   

14.
Cambrian-Ordovician sedimentary sequences crop out extensively in the area surrounding the Sarydzhaz River, a remote mountainous region situated in the eastern part of Kyrgyzstan. These sequences, composed essentially of fine siliciclastic lithologies, were deposited on a passive margin of the peri-Gondwanan Karatau-Naryn microplate. Palaeontological constraints for the age of these sequences are rare. Recent efforts of geological mapping in the area discovered reasonably well-preserved radiolarian and conodont faunas. The occurrence of conodonts was mentioned previously, but no taxonomic details were ever reported. Two conodont assemblages are identified from the Oldzhobai Formation; the first is dominated by Paracordylodus gracilis, which can be correlated with the upper Tremadocian to lower Floian; the second assemblage is more diverse and characterized by Prioniodus elegans, suggesting a mid Floian age. This is the first discovery of Ordovician Radiolaria from Kyrgyzstan. In spite of its rather moderately good to poor preservation, the fauna is interesting in many respects, especially due to the presence of a new radiolarian species (Inanigutta (?) kyrgyza nov. sp.). The latter is easily identifiable by the distinctive pore pattern of its cortical shell and has therefore the potential to become in the future a biostratigraphic marker species.  相似文献   

15.
Diverse conodont and silicified ostracod assemblages were found in the Spanish Pyrenees (Els Castells section), in the Frasnian/Famennian boundary beds (late rhenana and/or linguiformis to late triangularis zones), in strata below and above the well-known Kellwasser Extinction Event. Many of the ostracods studied here are conspicuous elements of the “Thuringian Mega-Assemblage”, and show maximum affinities with faunas from the southeastern Cantabrian Mountains (Spain), eastern Thuringia and the Harz (Germany). The composition of the faunas, however, is not uniform through the Els Castells section. A rather sharp break exists, roughly coinciding with the Frasnian/Famennian boundary. The break is characterized by the disappearance of many ostracods typical of the “Thuringian Mega-Assemblage”. This correlates with an important change in the conodont faunas related to the Kellwasser Event. The Frasnian (late rhenana and/or linguiformis zones) palmatolepid-polygnathid biofacies is followed in Famennian strata (middle and late triangularis zones) by a palmatolepid-icriodid biofacies. The icriodid maximum in the earliest Famennian rocks of the Pyrenees correlates with the “Icriodid Peak” described elsewhere. These changes depend on the age and palaeoenvironmental conditions.  相似文献   

16.
In 1930W.E. Schmidt described all known crinoids from the German Early Carboniferous, including the Etroeungt beds of Germany, which are now judged to be latest Devonian (Famennian) in age. On a global basis, Famennian camerate crinoids generally show a closer relationship to succeeding Early Carboniferous faunas than they do to older Frasnian or Middle Devonian crinoids, which also is the case for the Strunian fauna. Holdovers from older Devonian faunas include, among others,Adelocrinus, a descendant of olderArthroacantha, in England and Germany, andPetaloblastus, which is one of the youngest genera of the blastoid family Hyperoblastidae. Precursors of younger Early Carboniferous groups include platycrinoids, primitive actinocrinoids, dichocrinoids, and the blastoid genusDoryblastus, which is one of the oldest members of the family Orbitremitidae. All of these groups, which became important parts of the Early Carboniferous crinoid and blastoid radiation, give Famennian crinoid faunas much more of an Early Carboniferous than a Devonian aspect. Rhipidocrinus schmidti n. sp. is erected for specimens that originally were reported from the Etroeungt asRhodocrinus uniarticulatus. We judge that there are currently four valid species assigned toRhipidocrinus: R. crenatus, R. perloricatus, R. praecursor, and our new species,R. schmidti. Hydriocrinus ratingensis Schmidt is reassigned to ?Sostronocrinus. We note thatSchmidt (1906), notJaekel (1906) as has been reported previously, is the author ofRhipidocrinus perloricatus. Owing to the poor preservation of the Etroeungt material, we regard the namePlatycrinites wunstorfi Schmidt 1930 to be a nomen nudum.  相似文献   

17.
广西东南部钦州地区早石炭世放射虫化石   总被引:8,自引:7,他引:1  
广西钦州地区的板城石夹水库首次发现早石炭世杜内期和维宪期放射虫化石,计10属14种(亚种)和5未定种,其中有1新属(Guangxitrisphaera)和2新种(G.wanyaoensis和Pylentonemabanchensensis),它们分属于Albaillella paradoxa组合带和A.cartalla组合带。这些化石可以同西欧和北美两个同名化石组合带对比。  相似文献   

18.
Vertebrate microremains from the Late Devonian-Early Carboniferous of the Carnic Alps are predominantly chondrichthyan, with minor placoderm and actinopterygian remains. The faunas are sparse and, with very few exceptions, occur only in conodont-rich pelagic limestones (Pramosio Limestone) representative of the palmatolepid-bispathodid conodont biofacies. Phoebodont and jalodont chondrichthyans, also reflecting open-ocean environments, predominated during the Famennian, and eventually symmoriids seem to predominate during the Early Carboniferous. The presence of Siamodus in this assemblage gives a new locality for this genus known from few regions in the world and allows confirming its stratigraphical range (limpidus Zone) and its relation to deep-water environments. The Late Devonian vertebrate faunas are tropical and cosmopolitan, having much in common with coeval taxa from the North-Gondwanan margins and Asian terranes. Composition of the vertebrate faunas is consistent with the Carnic Alps terrane having occupied a position intermediate between Gondwana and Laurussia, as hypothesized by various authors, but because of sparsity of the taxa represented and the pronounced cosmopolitan nature of both the conodont and vertebrate faunas, the data are not compelling.  相似文献   

19.
The posidoniform bivalve species Posidonia becheri Bronn, 1828, has been identified for the first time in the Lower Carboniferous (Tournaisian) sandy limestone-dark grey shale deposits of Hakkari Province, south-eastern Turkey. Palaeogeographically, this area was located at the northern tip of the Gondwanan Arabian Palaeozoic platform at the southern Palaeotethyan margin during the Carboniferous. The closest localities to this new occurrence are the Lower Carboniferous of northern England, Germany (Kulm Basin), Poland (Walbrzych Basin), Northwest Belgium, Spain (Cantabrian Mountains), Portugal, and Northwest Turkey (Zonguldak Basin). All these locations are considered parts of the Avalonian or Perigondwanan terranes, and were located NW of the Palaeotethys. Hence, our new finding from the SE Palaeotethyan margin, together with the data from Morocco, indicates that this posidoniid bivalve had probably been transported by oceanic currents in its larval stage to lower palaeolatitudes (about 50° S) within the Palaeotethyan Ocean during the Early Carboniferous, or alternatively, the northern Arabian platform margin was located in lower latitudes than previously suggested.  相似文献   

20.
Permian ostracods are reported for the first time from the Wordian (Middle Permian) Khao Khad Formation of Saraburi Group (Lopburi Province, Central Thailand). The ostracod fauna consists of 18 species belonging to 11 genera including Bairdia, Bohlenatia, Liuzhinia, Silenites, Acratia, Bairdiacypris, Basslerella, Aurigerites, Microcheilinella, Paraparchites and Shemonaella. The studied Khao Khad Limestone, which are rich in fusulinids, gastropods, ostracods, bivalves and brachiopods, was deposited in a shallow carbonate platform on the western margin of the Indochina Terrane. The ostracod assemblage is typically Palaeo-Tethyan and similar to faunas from the other Lower to Middle Permian limestones in central Thailand.  相似文献   

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