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1.
Forty-two conodont species are documented from the Liuxia, Shijiatou and Jingshan formations in Zhejiang Province of southeast China, located palaeogeographically on the Jiangnan Slope offshore to the Yangtze Platform. From these faunas, eight successive conodont biozones of Tremadocian to middle Floian (Early Ordovician) age are recognized, including the Cordylodus lindstromi Biozone, Cordylodus angulatus Biozone, Chosonodina herfurthi Biozone, Paltodus deltifer Biozone, Paroistodus proteus Biozone, Triangulodus bifidus Biozone, Serratognathus diversus Biozone and Prioniodus elegans Biozone. Several zonal index species of the Baltoscandian succession—Paltodus deltifer, Paroistodus proteus and Prioniodus elegans—are described and illustrated in detail for the first time from South China. Co-occurrence of P. proteus and Serratognathus bilobatus in several samples below the appearance of P. elegans also confirms correlation of the S. diversus Biozone (basal Floian) with the upper P. proteus Zone of the Baltoscandian succession. These Zhejiang faunas are dominated by pandemic forms, and are similar to those of the Open-Sea Realm elsewhere, inhabiting deep, offshore environments.  相似文献   

2.
Abstract

Backfill material from a 12th- to13th-century quarry, north of Wallingford, south Oxfordshire, comprises sandy loam overlain by Cretaceous (early Cenomanian; Mantelliceras mantelli Macrofaunal Biozone) Glauconitic Marl Member, of the West Melbury Marly Chalk Formation as identified by its abundant, biostratigraphically useful, foraminifera and ostracods. A local outcrop source of the Glauconitic Marl Member, less than 1 km north of the quarry pit, is the likely provenance of this material, and a contemporaneous road, which was discovered adjacent to the medieval quarry by magnetometer surveys and archaeological excavation, would have aided its transportation, into the town via the North Gate. We hypothesise that the use of a calcareous marl to overlay sandy loam deposits probably encouraged land restoration when the quarried area was returned to pastoral agriculture.  相似文献   

3.
Invasive vegetation species can lead to major changes in the geomorphology of coastal systems. Within temperate estuaries in the southern hemisphere, especially Australia and New Zealand, the cordgrass Spartina spp. has become established. These species are highly invasive, and their prolific growth leads to the development of supratidal environments in formerly intertidal and subtidal environments. Here, we quantified the impact of Spartina invasion on the geomorphology and sequestration capacity of carbon in the sediments of Anderson Inlet, Victoria, Australia. Spartina was first introduced to the area in the 1930s to aid in land reclamation and control coastal erosion associated with coastal development. We found that Spartina now dominates the intertidal areas of the Inlet and promotes accretion (18 mm/year) causing the formation of over 108 ha of supratidal islands over the past 100 years. These newly formed islands are calculated to potentially contain over 5.5 million tonnes of CO2 equivalent carbon. Future management of the inlet and other Spartina‐dominated environments within Australian presents a dilemma for resource managers; on the one hand, Spartina is highly invasive and can outcompete native tidal marshes, thereby warranting its eradication, but on the other hand it is likely more resilient to rising sea levels and has the potential for carbon sequestration. Whether or not the potential advantages outweigh the significant habitat change that is anticipated, any management strategies will likely require additional research into costs and benefits of all ecosystem services provided by Spartina including in relation to nutrient cycling, shoreline stabilisation, and biodiversity as well as in response to the longevity of carbon found within the sediments.  相似文献   

4.
The palynoflora of surface samples of glacial deposits from the Guandacol Formation in the Cerro Bola area of the Argentinian Paganzo Basin is documented. The existence of glacial related diamictites in this area has been previously ignored. The fossiliferous levels are located in section B of the formation, which corresponds to the earlier stages of deglaciation. The assemblage contains abundant monosaccate pollen grains whose global incoming is not older than early Namurian (Middle Carboniferous). Many species of this palynoflora are present in equivalent stratigraphic sequences of Argentina and can be referred to Sub-biozone A of the Raistrickia densa-Convolutispora muriornata Biozone (Namurian-Stephanian). New species described here are Cyclogranisporites rinconadensis and Tricidarisporites gutii.  相似文献   

5.
Ordovician graptolite-bearing strata in eastern Yunnan were deposited in nearshore, shallow-water environments. Graptolites are systematically described from three sections through the Hungshihyen Formation in eastern Yunnan Province, China: (1) Hongshiya section near Ercun village, Kunming; (2) Liujiang section, Luquan; and (3) Guihuaqing Reservoir section, Luquan. The graptolite fauna, characterized by the predominance of deflexed forms, includes ten species in two genera: Baltograptus turgidus (Lee), B. varicosus (Wang), B. yunnanensis (Li), B. calidus (Ni), B. enshiensis (Ni), Baltograptus sp. cf. B. deflexus (Elles & Wood), Baltograptus sp. cf. B. bolivianus (Finney & Branisa), Baltograptus sp. A, Baltograptus sp. B and Corymbograptus v-fractus minor (Li). A detailed morphological study of these southern Chinese graptolite faunas suggests that Baltograptus wudingensis (Li) is a junior synonym of B. turgidus (Lee); Baltograptus kunmingensis (Ni) is a junior synonym of B. varicosus (Wang); and Baltograptus triangulatus (Ni) is a junior synonym of B. yunnanensis (Li). The B. varicosus Biozone is newly recognized within the middle part of the Hungshihyen Formation, replacing the former Didymograptus deflexus Biozone. This interval is well correlated to the Baltograptus jacksoni Biozone in Britain, the Tetragraptus akzharensis, ‘Baltograptus cf. deflexus’ and Didymograptus bifidus (lower part) biozones in NW Argentina (eastern Cordillera), and the Acrograptus filiformis and Didymograptellus eobifidus biozones in northern Guizhou, South China. Accordingly, the interval is of mid-Floian age, rather than late Floian as previously proposed.  相似文献   

6.
The evolution of littoral palaeoenvironments in the southern Pampas region of Argentina towards the end of the early Holocene and the beginning of the mid Holocene is discussed, and the formation processes of the archaeological site of La Olla are analysed. This site is located in the intertidal zone of the present beach and is remarkably well-preserved. The human occupation at the site has been dated at between 7400 and 6480 yrs BP, and is interpreted as a place for the processing and consumption of the southern fur seal (Arctocephalus australis) and southern sea-lion (Otaria flavescens). It is concluded that biostabilization by microbial mats of the sedimentary structures and archaeological remains that developed and are present on the tidal flat prevented their erosion by wind, turbulence currents and waves. This is what has permitted the exceptional preservation of the site. On the basis of the analyses of one of the sectors of the site it can be concluded that the sedimentary succession of the La Olla site is the result of the coastal environmental changes during the early–mid Holocene in the pre-maximum transgressive episode. During this interval a tidal flat developed on the Pleistocene abrasion platform. Human occupation occurred during the formation of mixohaline marsh, an upper intertidal–lower supratidal zone ecosystem.  相似文献   

7.
Unconsolidated sediments from a borehole in Botany Bay have been analyzed for their foraminiferal content. Faunas from between 41 and 54 m below sea level are interpreted as Pleistocene in age. The foraminiferal assemblage from 54 m indicates marine conditions of moderately deep water (25–30 m), and a climate warmer than at present. The higher assemblages indicate a more brackish environment

The foraminifera, belonging to 123 species in 67 genera, are tabulated and 24 are discussed and illustrated. Three species, Oolina bifidocostata, Fissurina alatoquadrata and Elphidium botaniensis and one subpecies, Quinqueloculina affinis atrata, are described as new.  相似文献   

8.
Diatom and dinoflagellate cyst analysis of a 77 cm long sediment core from Cowan Creek, Hawkesbury River estuary, N.S.W., revealed changes in the catchment hydrology over the last 266 years. High abundances of the freshwater/brackish diatom genus Cyclotella at the base of the core imply sustained periods of reduced salinity that now no longer occur. Reduction of freshwater flow after approximately circa 1800 (60 cm) has allowed the development of marine planktonic diatoms Thalassiosira spp.,Ditylum brightwellii, Rhizosolenia setigera, Pseudo-nitzschia pungens and Chaetoceros spp. Benthic diatom diversity has remained relatively unchanged. The toxic dinoflagellate Gymnodinium catenatum, although identified in a cyst survey in April 1995, was not found in the sediment cores. Changes in dinoflagellate assemblage are consistent with the effects of increasing urbanisation and eutrophication.  相似文献   

9.
Abstract

The site lies to the south of the High Street in Guildford’s town centre, SU 9980 4944. The pit yielded a large assemblage of artefacts. The significance of the assemblage lies in its size and its coherence as a single, chronologically uncontaminated and sealed deposit. The finds form a discrete group of ceramics, glass, clay pipes and organic remains dating from c.1650-1714, and deposited c.1702-14. Many of the vessels after reconstruction proved to be complete, or almost so. Because of the location of the site in Tunsgate, the artefacts must either have come from the Tun Inn, which had a frontage on the High Street, or from a property nearby belonging to the owner of the Tun Inn. The end of the 17th century and the beginning of the 18th century is a particularly interesting period for ceramic and glass studies and the finds from 16 Tunsgate reflect this. The assemblage contains previously unknown examples of the work of John Dwight and George Ravenscroft, a soda glass with a hitherto unknown type of seal, the largest group of mould-blown cristallo beakers so far found in the United Kingdom or North America and a unique group of animal remains that provide a snapshot of inn food in the early 18th century. The finds are on display in Guildford Museum.  相似文献   

10.
Precordilleran Late Palaeozoic brachiopod genera considered for this palaeobiogeographical analysis belong to four faunal associations: the low diversity Early Carboniferous (Tournaisian) Protocanites scalabrinii-Azurduya chavelensis Zone; the Late Carboniferous (Bashkirian-Moscovian) Levipustula fauna, which appears in sequences associated with glacial intervals; the latest Carboniferous-earliest Permian (Gzhelian-Asselian) Rhipidomella-Micraphelia and Tuberculatella-Aseptella associations, and the Early Permian (mid to late Asselian) Tivertonia jachalensis-Streptorhynchus inaequiornatus Biozone. The brachiopod affinities of the Precordillera are compared with the biogeographical Late Palaeozoic regions previously suggested by other authors using cluster analysis. During the Bashkirian-Moscovian, the Precordilleran faunas show a high affinity with the Austral Realm because of the presence of the Levipustula faunal elements in Eastern Australia. At the same time the affinity with the central and North American Regions is very low. The Early Permian Precordilleran faunas demonstrate highest affinity with the Gondwanan Realm with several genera also linked to the Tethyan and Boreal Realms. After the Late Carboniferous glacial episodes that affected the southwestern Gondwanan margin, the Precordilleran region underwent climatic amelioration. Subsequently, the Early Permian Precordilleran brachiopod assemblages are characterized by typical cool to cold water genera widely developed in the core Gondwanan Realm, with fewer genera (such as Kochiproductus, Rhynchopora and Neochonetes) suggesting a warmer water influence. The Precordilleran faunas demonstrate an increase in brachiopod diversity from the Carboniferous to the Permian, related to water temperature changes and to the palaeogeographical evolution of the southwestern Gondwanan margin and the movement of Gondwana across the South Pole.  相似文献   

11.
Qianyu Li & Brian Mcgowran, 1994:03:28. Evolutionary morphological changes in the new genus Duoforisa: implication for classification and habit of the unilocular Foraminifera. Alcheringa 18, 121–134. ISSN 0311-5518.

Unlike other unilocular foraminifera, the new genus Duoforisa from the Late Oligocene to Early Miocene possesses a kidney-shaped test with two apertures on its distal ends. It contains two distinct and successional species, both new, and differentiated by their apertural details. In Duoforisa rima the apertures are slit-like, and become radial in the descendant D. diducta. Intermediate forms have transitional apertural configurations between the slit type and radial type, accompanied also by a change of the test outline from subtriangular to compactly U-shaped. The evolution of the lineage occurred during a period of enhanced upwelling in the Early Miocene and it was terminated just before the global warming at the Early-Middle Miocene boundary. This example suggests evolution of the unilocular foraminifera through successional morphological changes in test shape and in the aperture. Unilocular taxa have tended to flourish or speciate in cool or upwelling environments. Their contraction in the latest Early Miocene to early Middle Miocene was probably due to global warming and well oxygenated conditions which were widespread in the neritic domains of southern Australia.  相似文献   

12.
Thirty ammonite taxa are recognised in the Wangarlu Mudstone of the Bathurst Island Group from the Cox Peninsula and Shoal Bay, Northern Territory, Australia. Included are a new heteromorph genus Notostreptites, type species N. exilis, and four additional new species and subspecies: Pseudhelicoceras gracilis, Labeceras (L.) tumidum, Labeceras (Appurdiceras) decorum, and Idiohamites dorsetensis laticostatus. The assemblage is best collectively correlated with the Mortoniceras (M.) inflatum Zone of the standard European Albian zonation but some of its members may represent the lower part of the Stoliczkaia dispar Zone. It is broadly correlative with faunas from the Eromanga Basin, which relate to an extensive eastern Australian Late Albian epicontinental sea, but is strikingly different in aspect. The Wangarlu Mudstone assemblage has relatively high diversity and an abundance of cosmopolitan heteromorph taxa well known from Europe and elsewhere, whereas Eromanga Basin assemblages are of relatively low diversity and dominated by Austral heteromorph genera known only from Australasia, southern Africa and Malagasy. The Austral character of Eromanga Basin assemblages is attributed to evolution in a restricted epicontinental sea environment and modest dispersal whereas the continental margin position of the Wangarlu Mudstone ensured an influx of pandemic elements drawn from the mid-Cretaceous world ocean.  相似文献   

13.
Trilobites are common faunal elements in the Melbourne Formation, a unit of early Ludlow (upper nilssoni Biozone) age, which crops out extensively in the Darraweit Guim Province of the Melbourne Zone, central Victoria. New diagnoses are given for species previously described, including Maurotarion euryceps (McCoy, 1876; = Cyphaspis spryi Gregory, 1901), Raphiophorus jikaensis (Chapman, 1912; = Ampyx yarraensis Chapman, 1912), Cromus simpliciculus (Talent, 1964), Cromus spryi (Chapman, 1912), Sthenarocalymene kilmorensis (Gill, 1945; = Gravicalymene hetera Gill, 1945) and Trimerus harrisoni (McCoy, 1876). A new phacopid genus, Orygmatos is described, represented by the species O. yanyeani gen. et sp. nov. Other species newly described include Cromus melbournensis sp. nov., Arcticalymene australis sp. nov., “Ananaspis” woiwurrungi sp. nov. and Kettneraspis hollowayi sp. nov.

Species composition of the trilobite fauna varies spatially, and a number of distinct assemblages can be defined. Abundant trilobite moult configurations are conclusive for interpretation of the benthic fauna as autochthonous, inferring depth estimations based on benthic community distribution to be valid. A depth-related succession of communities is recognised and indicate the Melbourne Formation was deposited at relatively shallow depths on a broad, eastwardly deepening shelf, with deposition dominated by storm processes. The palaeoenvironment comprised a BA-1 community including the Arcticalymene australis trilobite assemblage, restricted to very shallow depths (~20 m) on the SW coastal margin of the shelf and preserved in proximal tempestite lithologies; and a BA-5 community group containing three distinct trilobite assemblages dominated by species of Cromus and a deeper water fauna, preserved in distal tempestite lithologies and ranging widely over the shelf at depths in the range of maximum storm wave base (~50 – 80 m).  相似文献   

14.
The Lower–Middle Ordovician Zitai Formation of the South China palaeoplate consists of a succession of purple red, nodular argillaceous limestones. Palaeogeographically, it is distributed along the southeastern margin of the Yangtze Platform, and is of late Floian to Dapingian age, correlative with the Dawan Formation of the Middle and Lower Yangtze Platform. In Shitai County, Anhui Province, East China, the Zitai Formation is rich in conodonts, enabling the recognition of four biozones based on first appearance data. Detailed palaeontological and biostratigraphical study of these conodonts reveals that the Ordovician conodont radiation in the Lower Yangtze Platform attained its first diversity peak low in the Oepikodus evae Biozone. This diversification is generally consistent with macroevolutionary trends of brachiopods of South China and graptolites of the Upper Yangtze Platform, but was earlier than that of trilobites and acritarchs of the same palaeoplate. Correlation with the sea-level curve for South China suggests that conodont diversity change during the Ordovician radiation was mainly controlled by regional sea-level fluctuations.  相似文献   

15.
Vandenberg, A.H.M., December 2017. Didymograptellus kremastus n. sp., a new name for the Chewtonian (mid-Floian, Lower Ordovician) graptolite D. protobifidus sensu, non. Alcheringa 42, 259–268. ISSN 0311-5518.

The ‘tuning-fork’ didymograptid previously referred to as Didymograpt(ell)us protobifidus is common in Victoria where it is confined to the Chewtonian (mid-Floian). Biometric differences indicate that the mid-Floian form is not conspecific with the holotype of the Darriwilian Didymograptus protobifidus Elles, 1933 and the Floian form is thus renamed Didymograptellus kremastus n. sp. Study of the Valhallfonna Formation faunas on Spitsbergen indicated that the Floian form of D.protobifidus’ differs from Didymograptellus bifidus (Hall) in both its morphology and stratigraphic distribution but a later study of the Cow Head Group on Newfoundland concluded that they are one species. My study, of more than 50 specimens of Didymograptellus from the Floian of Victoria, Australia, shows that the two are different and that similar differences exist in the Cow Head Group populations of Didymograptellus. The Chewtonian (Ch1) Didymograptellus protobifidus Biozone is renamed D. kremastus Biozone.

Alfons H.M. Vandenberg, [], [] Museums Victoria, GPO Box 666, Melbourne 3001, Victoria, Australia.  相似文献   


16.
Wezmeh Cave is located on the northeastern edge of the Islamabad plain, a high intermontane valley in the western‐central Zagros. In 1999 a disturbed but large faunal assemblage was recovered from this site. The abundant and extremely diverse faunal spectra present at Wezmeh Cave has highlighted the importance of this assemblage. Carnivore remains constitute the bulk of the assemblage; red fox (Vulpes vulpes) has the highest number of identified specimens followed by spotted hyena (Crocuta crocuta), brown bear (Ursus arctos), wolf (Canis lupus), felids (lion, leopard, lynx/caracal and wildcat), mustelids (badger, polecat, marten) and viverrids (mongoose). Artiodactyls (bovid, cervid, suid), equids, rhinoceros (Dicerorhinus sp.) and small animals (Cape hare, porcupine, tortoise, snake, birds) are also present. According to U‐series dating, the site was occupied from around 70 ka BP through to sub‐recent periods by carnivores. Amongst this rich assemblage, a human fossil tooth was also found and dated by non‐invasive spectrometry gamma dating to 20–25 ka BP. A preliminary zooarchaeological and taphonomic study shows that Wezmeh Cave was used by multiple carnivore species, a unique phenomenon in the Zagros Mountains in particular and southwest Asia in general. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

17.
Samples from off southern New South Wales in approximately 1750 m water depth have yielded late Paleocene faunas of benthic and planktonic foraminifera and other invertebrates. Two faunal associations with a strong Tethyan influence, dominated respectively by Chapmanina conjuncta sp. nov. and Reticulophragmium naroomaensis sp. nov., are described; this is the first formal record of these genera from Australasia. The age of the host sediment is based on both benthic species and few planktonic foraminifera.

The environment at the time was warm temperate to subtropical at the southwestern extremity of a counter-clockwise Pacific Ocean gyre. The new occurrence extends the record of Palaeogene marine sediments and palaeoenvironments along the eastern margin of Australia and confirms earlier observations that conditions in the marine environment at that time were considerably warmer along the east coast of Australia than those along the southern margin; the biogeographic association was Tethyan. The circulation model may go some way to explaining coeval warmth along the east Antarctic coast.  相似文献   

18.
The discovery of a rich assemblage of microfossils from the Neoproterozoic western Officer Basin (Centralian Superbasin) provides a more complete understanding of the biostratigraphy of this Basin. The microfossils are found in Supersequence 1 (~800 Ma) in Western Australia. The assemblages are comprised of acritarchs and cyanobacteria isolated by acid maceration from siliciclastics of the Browne (Madley), Hussar, Kanpa and Steptoe Formations. The distinctive acritarchs Cerebrosphaera buickii, Satka colonialica, Stictosphaeridium sinapticuliferum and Pterospermopsimorpha insolita are of particular interest in the Neoproterozoic. These taxa are found in similar depositional environments in Spitsbergen, Arizona, Canada and Siberia. This evidence, together with lithostratographic correlations, isotope chemostratigraphy, and sequence analysis contributes to the continuing development of Neoproterozoic stratigraphy.  相似文献   

19.
Liang Bua is a limestone cave on the island of Flores, Indonesia. Palaeontological and archaeological excavations at this site have unearthed one of the best insular records of fossil bats to date. The assemblage is numerically dominated by the horseshoe bat species Rhinolophus euryotis, followed by the leafnosed bat Hipposideros diadema. In addition to these species, remains of Rhinolophus simplex, Hipposideros sp. cf. H. sumbae, Murina sp. aff. M. florium, Taphozous sp., Kerivoula sp. and Miniopterus sp. have also been recovered. Two taxa found in Liang Bua, Rhinolophus euryotis and Miniopterus sp., are not apparent in the modern bat fauna of Flores. Some specimens, found during the more recent excavations, are known from specific depths. Two age-groups are represented. The stratigraphically oldest is 74–61 ka and includes Murina sp. aff. M. florium and Rhinolophus euryotis. Conversely, the younger, Holocene, assemblage is much more diverse. Despite the relatively small amount of microbat material collected thus far, it displays a higher diversity than the rodents from the site. This is presumably related to the better dispersal ability of bats relative to other, non-volant mammals.  相似文献   

20.
As part of our investigations into the potential of the Republic of Georgia for providing information on early hominin occupation of Eurasia, we report here on Akhalkalaki, a large late Early Pleistocene locality located along the lower slopes of a Miocene andesitic cone. Originally excavated in the 1950s as a palaeontological site, it was re-opened in the 1990s and stone tools were found associated with the fauna, suggesting that it is also an archaeological occurrence. Excavations in the 1950s and 1990s uncovered thousands of bones of an early Galerian fauna, including the remains of new species of Hippopotamus,Equus , and Canis (Vekua, 1962, 1987) and dominated by the remains of Equus süssenbornensis. We present the stratigraphy of the site, which together with faunal correlations and reversed paleomagnetics indicates an age most likely in the late Matuyama Chron, probably between 980,000 and 780,000 years ago. Taphonomic analysis suggests that the fauna was deposited and buried over a short time period, and was heavily modified by carnivores, but we cannot demonstrate involvement by hominins. Based on evidence of abundant krotovina (animal burrows filled with sediment) and the lack of definitive evidence for hominin modification to the bones, the stone tools at the site may have been mixed in with the older fauna. The taphonomic characteristics of the Akhalkalaki bone assemblage are not readily explained with reference to assemblage formation processes developed with actualistic studies that have been mostly conducted in Africa, including carnivore dens, predator arenas, human hunting and scavenging, mass deaths, or attritional bone deposition. Because of extreme anthropogenic modification of the present environments, the temperate setting, and the presence of mainly extinct taxa, local models based on actualistic studies cannot approximate the mammalian ecology reflected in the Akhalkalaki bone assemblage. A few comparisons are made with preliminary taphonomic observations from Dmanisi, an Early Pleistocene Homo ergaster site not far away.  相似文献   

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