Dinoflagellate cysts of the Quaternary System

Harland, Rex

doi:10.1007/978-94-011-2386-0_5

Cited by 14 publications

(8 citation statements)

References 49 publications

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“…cysts, are indicative of a relatively nearshore, glacial environment with seasonal or permanent sea-ice. The presence of Brigantedinium simplex is indicative of a Mid Pleistocene or younger age (Harland, 1992). The palynomorph content of the three samples proved relatively constant and the succession appears to be part of the same genetic sequence.…”

Section: P R O V a Smentioning

confidence: 91%

A review of the laboratory preparation of palynomorphs with a description of an effective non-acid technique

Riding¹

2004

RBP

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The preparation of palynomorphs for microscopy has traditionally used hydrochloric acid (HCl), hydrofluoric acid (HF) and nitric acid (HNO 3). The use of these acids is both expensive and hazardous. An effective technique of preparation using sodium hexametaphosphate [(NaPO 3) 6 ] has been developed. The cleaned, crushed and softened sample is treated with (NaPO 3) 6. The deflocculated clay is then sieved away and the residue centrifuged. This method has been successfully tested on seven Jurassic to Quaternary sample sets from the United Kingdom (UK) and Antarctica. In five of these sets, the rock/sediment was prepared using the mineral acid technique and the (NaPO 3) 6 procedure. Four of these five sample suites were prepared by both methods quantitatively, so that the concentrations of palynomorphs can be compared. The (NaPO 3) 6 method largely proved to be equally as effective as the mineral acid procedure. The Lower Toarcian Whitby Mudstone Formation of Leicestershire and the Middle and Upper Albian Gault Formation of Kent both produced similar palynomorph/kerogen associations. Some differences between the two procedures were, however, noted. The (NaPO 3) 6 method produced significantly better results than acid preparations for the uppermost Cretaceous (Maastrichtian) of Antarctica and the Pleistocene Till of northern England. By contrast, the majority of the samples from the in situ late Campanian-early Maastrichtian White Chalk Subgroup of north Norfolk prepared using HCl, were significantly richer in palynomorphs than those treated with (NaPO 3) 6.

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Section: P R O V a Smentioning

confidence: 91%

A review of the laboratory preparation of palynomorphs with a description of an effective non-acid technique

Riding¹

2004

RBP

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“…Species diversity and temporal distribution were determined by merging four published compilations of dinoflagellate cyst occurrences (21,(55)(56)(57). Rather than being exhaustive compilations of all described species, these biostratigraphic compilations include only well established and common species, an approach that is useful in avoiding the biases of monographic effects and synonyms.…”

Section: Methodsmentioning

confidence: 99%

A universal driver of macroevolutionary change in the size of marine phytoplankton over the Cenozoic

Finkel¹,

Sebbo

Feist-Burkhardt

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

102

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The size structure of phytoplankton assemblages strongly influences energy transfer through the food web and carbon cycling in the ocean. We determined the macroevolutionary trajectory in the median size of dinoflagellate cysts to compare with the macroevolutionary size change in other plankton groups. We found the median size of the dinoflagellate cysts generally decreases through the Cenozoic. Diatoms exhibit an extremely similar pattern in their median size over time, even though species diversity of the two groups has opposing trends, indicating that the macroevolutionary size change is an active response to selection pressure rather than a passive response to changes in diversity. The changes in the median size of dinoflagellate cysts are highly correlated with both deep ocean temperatures and the thermal gradient between the surface and deep waters, indicating the magnitude and frequency of nutrient availability may have acted as a selective factor in the macroevolution of cell size in the plankton. Our results suggest that climate, because it affects stratification in the ocean, is a universal abiotic driver that has been responsible for macroevolutionary changes in the size structure of marine planktonic communities over the past 65 million years of Earth's history.cell size ͉ climate change ͉ dinoflagellates ͉ evolution ͉ food webs M arine phytoplankton are a polyphyletic group of unicellular or colonial photoautotrophs (1) that range in size from Ͻ1 m to Ͼ1 mm in equivalent spherical diameter, corresponding to Ͼ8 orders of magnitude variation in cell volume. Because cell size influences nutrient uptake kinetics, photosynthesis, respiration, growth, and sinking rates (2-5), as well as genome size and rate of evolution (6, 7), the size structure of phytoplankton assemblages strongly inf luences energy transfer through the food web and tempo of evolution in the sea (8-10). Based on analyses of fossil records over the Cenozoic, macroevolutionary changes in cell size have been reported for marine diatoms (11), coccolithophorids (12), and the amoeboid planktonic foraminifera (13-15); however, the underlying causes of such changes remain unclear. Broadly, hypotheses accounting for macroevolutionary trends fall into two groups: (i) specific biotic or abiotic forcings unique to each taxon or (ii) taxonspecific responses to a universal abiotic factor. Here, based on an analysis of the fossil record, we report that, like the other plankton groups examined, dinoflagellates exhibit an active macroevolutionary change in size in concert with changes in the thermal contrast between the surface and deep ocean. These results strongly suggest that a universal abiotic driver related to climate is responsible for macroevolutionary changes in the size structure of marine planktonic communities over the past 65 million years of Earth's history.Dinoflagellates are a group of unicellular eukaryotic flagellates characterized by a longitudinal and a transverse flagellum and are often armored with cellulosic plates. There are Ϸ2,...

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“…Dinoflagellate cysts (further shortly named dinocysts) are an important part of the plankton in nutrient-enriched waters like marginal seas and oceanic fronts and provide potentially useful stratigraphical datums (Harland, 1992;Cameron et al, 1984) in the North Sea Basin. Detailed information about the British stratigraphical stages (Fig.…”

Section: Bmentioning

confidence: 99%

Integrated chronostratigraphy of the Pliocene-Pleistocene interval and its relation to the regional stratigraphical stages in the southern North Sea region

Kuhlmann

Langereis

Munsterman³

et al. 2006

Netherlands Journal of Geosciences

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Time-stratigraphic interpretations of Late Pliocene to Early Pleistocene sediments from onshore locations and from marginal marine settings of the North Sea Basin often refer to the subdivision of the Dutch and British ’Quaternary’ regional stratigraphic stages. Since age control for these stages and their stage boundaries are based on relative dating methods, in this study pollen, dinoflagellate cysts and foraminiferal assemblages were investigated to correlate the regional stratigraphic stages independently to the global chronostratigraphy and the paleomagnetic timescale. The data were obtained from eight boreholes located in the depocentre setting of the Late Pliocene North Sea Basin comprising a 1000 m thick sedimentary succession. The British Gedgravian and Waltonian stages, the Dutch Reuverian to Brunssumian as well as published foraminiferal zones (NSB 14, FB and the lower part of the FA2 zone) fall within the Zanclean and Piacenzian. The lower boundaries of the Pre-Ludhamian and Pretiglian stages and of the NSB 14 to 15 zones are close to the paleomagnetic Gauss-Matuyama boundary. The Pre-Ludhamian, Ludhamian, Thurnian and the Pretiglian, Tiglian A and Tiglian B stages presumably cover the marine isotope stages 103 to 95. It is proposed that the Ludhamian, Thurnian and the Tiglian A were short lasting, warm, periods during which sea level highstand facilitated sedimentary deposition at the marginal areas of the North Sea Basin. The lower boundary of the paleomagnetic Olduvai subchron is situated in the Tiglian Cl-4b stage while the TC4c stage is found within the Olduvai subchron. Foraminiferal NSB 15 and NSB 16 zone as well as the upper part of the FA2 and FA1 zone fall within the Gelasian and cover the Matuyama chron as well as the lower part of the Olduvai subchron. Comparison with formerly dated North Sea sediments shows a good agreement between foraminiferal zonations on a broader scale but significant differences in absolute ages occur. Strontium isotope values indicate approximately 1 Ma younger ages as expected from our chronostratigraphic model. This discrepancy is explained by the dominance of freshwater from river discharge contributing high amounts of eroded material to the basin, leading to an increase of the 87Sr/86Sr ratio in the shelf-sea water.

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Dinoflagellate cysts of the Quaternary System

Cited by 14 publications

References 49 publications

A review of the laboratory preparation of palynomorphs with a description of an effective non-acid technique

A review of the laboratory preparation of palynomorphs with a description of an effective non-acid technique

A universal driver of macroevolutionary change in the size of marine phytoplankton over the Cenozoic

Integrated chronostratigraphy of the Pliocene-Pleistocene interval and its relation to the regional stratigraphical stages in the southern North Sea region

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