The Micropalaeontological Society

All posts in AGM

The Annual General Meeting was held on 26th November at University College London.

Following Society business, two talks were presented.

The use of reworked palynomorphs in the provenance analysis of the Crag Group (Pleistocene) and the pre-Devensian glacial deposits of East Anglia

J.B. Riding1, J. Rose2, R.J.O. Hamblin1, B.S.P. Moorlock1, S.J. Booth1, J.R. Lee2 and S. Pawley2
1British Geological Survey, Keyworth, Nottingham, Nottinghamshire
2Department of Geography, Royal Holloway, University of London, Egham, Surrey

Allochthonous palynomorphs have proved extremely useful in the provenance analysis of the Crag Group and the overlying pre-Devensian glacial succession in East Anglia, southeast England. The Crag Group is dominantly fluvial and palynomorph-bearing sedimentary clasts picked up inland to the north and west, especially where the rivers were of high erosive force, can help model the paths of these major drainage elements. Likewise, the palynological content of Till sheets can also provide valuable evidence of provenance. In both the Crag Group and the Till succession, Carboniferous and Jurassic palynomorphs may be especially common, with lesser proportions of Cretaceous and Palaeogene elements. Palynomorphs of Silurian to Quaternary age have been observed.

Both derived palynofloras and clast lithologies from river and shallow marine sediments have been used to correlate pre-Anglian fluvial and coastal deposits in eastern England. The results are used to provide a lithostratigraphical framework for the Early and early Middle Pleistocene sediments, and to derive sedimentary models that can be linked to the tectonic and climatic processes that determined the behaviour of the geological systems. Three geological systems are recognised. i) The river Thames, which drained an area from Wales through Midland England to the Thames basin and southern East Anglia and reached the southern North Sea delta in the region of southern East Anglia. ii) The Bytham river which drained midland England and the southern Pennines and reached the southern North Sea delta in the region of north central East Anglia. iii) The Ancaster river which drained the southern Pennines and received sediment from northeast England. This river reached the sea in, and north of, northern East Anglia and contributed to some of the Cromer Forest-Bed. Each of these rivers contributed to the shallow marine sediments that formed around the eastern margin of the southern North Sea delta/estuary and are known as the Red, Norwich, and Wroxham Crag formations.

Similarly, the study of allochthonous palynomorphs can be effectively applied to the provenance of the pre-Devensian glacial deposits of Norfolk. Traditionally these deposits have been divided into a Lowestoft Formation, overlying a North Sea Drift Formation, the latter including three or four tills. All were considered to be Anglian, Oxygen Isotope Stage (OIS) 12. However, detailed mapping has demonstrated that the Lowestoft Till equates to the Walcott Till or Second Cromer Till, the second of the North Sea Drift tills. The deposits underlying the Lowestoft Till are now termed the Happisburgh Formation and were derived from northern Britain and the North Sea. The Lowestoft Formation is overlain by the Bacton Green or Third Cromer Till, for which derivation from northern Britain and the North Sea is also proposed; no Scandinavian erratics have been found in this till. The Bacton Green Till is overlain by the Overstrand Formation. This includes both sandur deposits (Briton’s Lane Member) and till (Stody Member), both of which are dominated by coarse, rounded flints. Unlike the earlier formations, the Overstrand Formation reveals constructional geomorphology and contains Scandinavian erratics, and an OIS 6 age is proposed for this glaciation, corresponding to the major glaciation in the Netherlands.

Micropalaeontology in the service of archaeology: advances in Quaternary biostratigraphy and palaeoenvironmental analysis
using foraminifera and ostracods

J.E. Whittaker1, Dave Horne2 & Bob Wynn Jones3
1Department of Palaeontology, Natural History Museum, Cromwell Road, London
2Department of Geography, Queen Mary College, University of London
3BP Exploration, Sunbury-on-Thames, Middlessex

It all started with Boxgrove! Traditionally, palynology had been the foremost tool in the micropalaeontological interpretation of the Quaternary. At the world-famous Boxgrove archaeological site (of Cromerian age), West Sussex, however, poor preservation of palynomorphs resulted in a need to consider other options; consequently I was asked, about ten years ago, to assess the potential of ostracods and foraminifera as palaeoenvironmental proxies and dating tools at Boxgrove. Results were encouraging and led to further requests to analyse calcareous microfossils from other archaeological sites, including the Aldingbourne, Brighton-Norton, and Selsey raised beaches in Sussex, as well as further afield. Soon, however, it was realised that taxonomic nomenclature in both microfossil groups needed substantial revision if they were to be used effectively to circumvent the loss of valuable climatic, environmental and biostratigraphic information due to misidentifications. Case histories from several UK sites are presented here and provide examples of successes resulting from exciting new discoveries, as well as some cautionary tales. A case is made for a renewed effort to establish a standard taxonomic database of Quaternary ostracods and foraminifera that extends well beyond the boundaries of NW Europe. The need for a harmonisation of biological and palaeontological classifications, particularly of freshwater ostracods, is also highlighted.

The Annual General Meeting was held on 20th November at University College London.

Following Society business, two talks were presented.
ICS on Stage

Felix M.Gradstein
Chairman of the International Commission on Stratigraphy (ICS)
Geological Museum, University of Oslo, Norway

The most important issue presently on the agenda of the International Commission on Stratigraphy (ICS) is the completion of the definition of stages scheduled for the year 2008; the author will outline the concept in its historical and its actual context. Special challenges exist with the definition of Precambrian, Cambrian, Ordovician and Quaternary stratigraphic units.

A newly created Stratigraphic Information System (SIS) is making important stratigraphic informationy easily available world-wide and also plans to offer assistance with teaching of stratigraphy in the earth-science curriculum of universities and high-schools. The URL stratigraphy.org is the official website of  ICS and its SIS. Geoscientists can now quickly find key stratigraphic information like stage boundary stratotypes, the International Stratigraphic Guide, the Standard Stratigraphic Chart with its colour coding scheme(s) and the standard Geological Time Scale.

ICS is also in the process of creating an electronic science journal called E-Strata.

In 2004 a new version will be published of the Standard Geological Time Scale with many stage boundaries dated significantly different from before, particularly in Ordovician, Devonian, Permian, Triassic, Lower Jurassic, Lower Cretaceous and Paleocene.

ICS is in the steering committee of the CHRONOS Network for Earth System History that develops Integrated Databases, Portals and Toolkits linked to the standard time scale. CHRONOS will  deliver a dynamic, interactive and refined framework for Earth System History based upon a network of comprehensive databases spanning the evolution and diversity of life, climate change, geochemical cycles, core-to-crust processes and other aspects of the Earth system.  Research and outreach portals equipped with powerful analytical and visualization tools will enable exploration and understanding of our evolving planet. The industry supported Network of Offshore Records in Geology and Stratigraphy (NORGES) developed and operated by the Geology Museum of Oslo University will link to and benefit from CHRONOS.

Freshwater diatoms as monitors of environmental change in the tropical Americas

Prof. Sarah Metcalfe  (Department of Geography, University of Edinburgh, UK)

The impact on the environment of both climatic change and human activities is of growing concern. It is clear that tropical areas are particularly vulnerable to both, but usually lack the long term monitoring data which can provide some form of baseline assessment of natural variability and sensitivity to disturbance. Freshwater diatoms can provide alternative archives of change over a variety of timescales. Results from Mexico and Belize are used to illustrate applications of diatoms to issues of climate change and human disturbance over timescales from millennia to sub-decadal. Increasingly, such reconstructions exploit not only the diatom assemblages per se, but the isotopic signatures preserved in the diatom frustules. Whilst offering many advantages for reconstructing environmental change there are conditions which hamper diatom studies and some of these are also discussed in the Central American context.

The Annual General Meeting was held on 21st November at University College London.

Following Society business, two talks were presented.

Microvertebrates and macroevolution – unravelling the origin and early history of the vertebrate clade
Dr Paul Smith, Dr Philip Donoghue and Dr Ivan Sansom (School of Earth Sciences, University of Birmingham)

The study of Early Palaeozoic microvertebrate faunas has, in the last decade, had a major impact on the understanding of vertebrate palaeobiology. A review of pre-Silurian vertebrates carried out as recently as 1991 concluded that only five species could confidently be included in the clade. Since then, a number of key discoveries have been made, many of them reliant on micropalaeontological methodologies. For example, the first armoured fish are now known to be present in the Late Cambrian, and the biodiversity of Ordovician vertebrates is far higher than previously suspected, even at high taxonomic levels. One particularly important change has been the increasing recognition that conodonts are vertebrates, which has both changed the temporal perspective of vertebrate phylogeny and increased the known generic and specific diversity by two orders of magnitude. Together, these developments demonstrate the importance of integrating micropalaeontological and traditional, vertebrate macrofossil, datasets since neither picture is complete in itself. The new discoveries have a significant part to play in elucidating the phylogeny of the group and in testing evolutionary scenarios, in assessing the completeness of the fossil record of early vertebrates, and in the determination of biogeographic and large-scale ecological patterns and processes.

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