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Synchronous Eocene/Oligocene high latitude cooling: ODP Site 913, Norwegian-Greenland Sea
No full textNew dinoflagellate cyst species from Upper Jurassic to Lower Cretaceous sediments of the Volgian lectostratotype sections at Gorodische and Kashpir, Volga Basin, Russia
No full textSix new dinoflagellate cyst species are described from a high-resolution palynological study of the Volgian (Upper Jurassic) to Valanginian (Lower Cretaceous) sequences at the Gorodische and Kashpir sections in the Volga Basin, Russia. The following taxa are described: Aprobolocysta pustulosa sp. nov., Cyclonephelium? bulbosum sp. nov., Meiourogonyaulax distincta sp. nov., Cribroperidinium magnificum sp. nov., Cribroperidinium undoryensis sp. nov., and Thalassiphora? robusta sp. nov. These new dinocyst species are stratigraphically restricted and may prove to be useful
taxa for regional biostratigraphic correlation
Palaeoenvironment and taphonomy of dinosaur tracks in the Vectis Formation (Lower Cretaceous) of the Wessex sub-basin, southern England
No full textReptilian ichnofossils are documented from three levels within the coastal lagoonal Vectis Formation (Wealden Group, Lower Cretaceous) of the Wessex Sub-basin, southern England (coastal exposures of the Isle of Wight). Footprints attributable toIguanodonoccur in arenaceous, strongly trampled, marginal lagoonal deposits at the base of the formation, indicating relatively intense ornithopod activity. These were rapidly buried by influxes of terrestrial and lagoonal sediment. Poorly-preserved footcasts within the upper part of the Barnes High Sandstone Member are tentatively interpreted as undertracks. In the stratigraphically higher Shepherd's Chine Member, footcasts of a small to medium-sized theropod and a small ornithopod originally constituted two or more trackways and are preserved beneath a distinctive, laterally persistent bioclastic limestone bed, characterised by hypichnialDiplocraterion. These suggest relatively low rates of dinosaurian activity on a low salinity, periodically wetted mudflat. Trackway preservation in this case is due to storm-induced shoreward water movements which generated influxes of distinctive bioclastic lithologies from marginal and offshore lagoonal settings. The rapidly-deposited footprint-fills occasionally contain fully articulated shallow burrowing bivalves. <br/
Sourcing mudsprings using integrated paleontological analyses: an example from Wootton Bassett, Wiltshire, England
No full textThis paper presents comprehensive macro- and micropalaeontological analyses of taxa recovered from mud and stream lags disgorged from mudsprings at Wootton Bassett, Wiltshire, England. These mudsprings are unusual as they are found in a stable intraplate tectonic setting, but the techniques and provisos employed in this investigation can equally well be employed to source the material venting from other mudsprings, including those found in compressional tectonic settings. The Wootton Bassett mudsprings Site of Special Scientific Interest at Templars Firs (Wiltshire, England), has become renowned through considerable media coverage over the past few years, largely on account of the well preserved fossils exhumed in the outpourings of mud from a series of springs. However, it is emphasized that care must be exercised when undertaking sourcing investigations to ensure that the possibilities of contamination are minimized. Thus micropalaeontological analysis of freshly disgorged mud samples is shown to be a more accurate method of obtaining biostratigraphic information than the use of macrofossil material from stream lags. The erupted material contains biostratigraphically diagnosed microfossil species from several Later Jurassic ammonite zones, indicating sourcing from more than one subsurface stratigraphical horizon. Integrating this information with the local lithostratigraphy described herein, the source material for the mud can therefore be identified as the local Ampthill and Kimmeridge clays immediately underlying the site at a depth of around 10 m
The provenancing of flint artefacts using palynological techniques
No full textThe provenancing of flint artefacts has proved problematic in the past. Acid maceration to extract age-diagnostic organic-walled microplankton from sedimentary materials is a technique routinely employed in both industrial hydrocarbon exploration and Quaternary studies. Here we assess the application of this technique to provenance determination of flint nodules from three locations (two in southern England and one in the Inner Hebrides, Scotland), each of which has abundant local evidence of flint utilization for artefact manufacture in prehistory. We show that, whilst not all flint nodules yield abundant or well preserved organic-walled microfossils assemblages, there is a significant potential for the use of this technique, which deserves further investigation
Greenhouse to icehouse: a biostratigraphic review of latest Devonian–Mississippian glaciations and their global effects
No full textThe latest Devonian–Mississippian interval records the long-term transition from Devonian greenhouse conditions into the Late Palaeozoic Ice Age (LPIA). This transition was punctuated by three short glaciation events in the latest Famennian, mid-Tournaisian and Visean stages, respectively. Primary evidence for glaciation is based on diamictite deposits and striated pavements in South America, Appalachia and Africa. The aim of this review is to assess the primary biostratigraphic and sedimentological data constraining diamictite deposits through this transition. These data are then compared to the wider record of eustasy, mass extinction and isotope stratigraphy in the lower palaeolatitudes. Precise age determinations are vital to integrate high- and low-palaeolatitude datasets, and to understand the glacial control on wider global changes. Palynological techniques currently provide the best biostratigraphic tool to date these glacial deposits and to correlate the effects of glaciation globally. This review highlights a high degree of uncertainty in the known history of early LPIA glaciation as much of the primary stratigraphic data are limited and/or unpublished. Future high-resolution stratigraphic studies are needed to constrain the history of glaciation both spatially and temporally through the latest Devonian and Mississippian
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