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Richard C. Preece - One of the best experts on this subject based on the ideXlab platform.
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Mollusca from Last Interglacial fluvial deposits of the River Thames at Trafalgar Square, London
Journal of Quaternary Science, 1999Co-Authors: Richard C. PreeceAbstract:An account is given of the molluscan assemblages recovered from fluvial deposits beneath the ‘Upper Floodplain terrace’ of the River Thames in the vicinity of Trafalgar Square, central London. A total of 37 aquatic and 28 terrestrial taxa have been recorded, a diversity indicative of full interglacial conditions. Palaeobotanical and vertebrate evidence suggests that these fossiliferous sediments belong to the Last (Ipswichian) Interglacial, a conclusion strongly supported by molluscan evidence. The combination of the presence of certain species, such as Belgrandia marginata, Potomida littoralis and Margaritifera auricularia, together with the absence of other taxa that no longer live in Britain, such as Pisidium clessini, Corbicula fluminalis and Unio crassus, imparts a distinctive character to the fauna. These temperate molluscs were not only present in the Trafalgar Square Sands and Silts, but also in the underlying Spring Gardens Gravel, showing the latter to be an interglacial aggradation that did not accumulate during the late Wolstonian, contrary to previous interpretations. Copyright © 1999 John Wiley & Sons, Ltd.
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Late and Middle Pleistocene deposits at Somersham, Cambridgeshire, U.K.: a model for reconstructing fluvial/estuarine depositional environments
Quaternary Science Reviews, 1999Co-Authors: Richard Gilbert West, John T Hollin, J. A. Catt, M. E. Pettit, K.l. Knudsen, David N. Penney, R. Andrew, C.p. Hart, G.f. Miller, Richard C. PreeceAbstract:Gravel quarries at Somersham, Cambridgeshire, have yielded evidence for a Pleistocene channel of the R. Great Ouse, containing temperate stage sediments between cold stage sediments. In the earlier cold stage, fluviatile gravels and floodplain loessic sediment accumulated. In the later cold stage a further series of gravel units and floodplain sediments were deposited, together with lake sediments. The lake sediments are associated with Lake Sparks, dammed by Late Devensian ice in the Wash at ca. 18.5 ka BP. The lake sediments overlie gravels with a radiocarbon date from an organic horizon indicating a Middle Devensian age. Clast lithological analyses from the earlier and later gravels suggest that reworking of gravels has occurred within a relatively stable catchment. The petrography of the earlier cold stage loessic sediment and temperate stage fine sediment indicates an Anglian affinity, which conflicts with the biostratigraphic interpretation. Pollen and macroscopic plant remains from sediments of both cold stages and from the temperate stage indicate, respectively, assemblages with a typical full-glacial aspect with a rich flora of shrubs and open ground herbs(including an assemblage at ca. 18 ka), and temperate freshwater and marine-influenced organic sediments. On the basis of pollen analysis these are ascribed to substages Ip II and III of the Ipswichian Stage(O.I.S. 5e), with a Pinus-Quercus-Corylus biozone in the former and a biozone with Carpinus in the latter. Marine-influenced sediments, at −3.7 to −0.3 m OD, indicate transgression in Ip II and regression in Ip III. Molluscan assemblages from the temperate stage and the later cold stage are described; two are from the Late Devensian, at a time near the maximum extension of ice into the Wash. Foraminifer and ostracod faunas are described from post-Ipswichian sediments and may be reworked. Radiocarbon dates confirm the age of the later gravel suite as Devensian and a calibration of the measurements is given. Amino acid ratios from Corbicula fluminalis valves from temperate stage sediments are reported, with measurements from different parts of the valve; the results tend to support an Ipswichian age. TL measurements of the earlier cold stage loessic sediment and associated sand indicate a pre-Ipswichian age for the sediments. The earlier cold stage is correlated with the pre-Ipswichian cold stage, the Wolstonian of Mitchell et al.(1973); problems with this correlation are discussed. Various periglacial phenomena, including thermal contraction networks and cracks, diapirs, involutions and coversand are associated with the Devensian sequence. The complex environmental history, based on stratigraphy and palaeontology, is described, and related to other nearby sites in southern Fenland.
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Late Pleistocene interglacial deposits at Pennington Marshes, Lymington, Hampshire, southern England
Proceedings of the Geologists' Association, 1996Co-Authors: Lorraine G. Allen, Richard C. Preece, M. E. Pettit, Philip L. Gibbard, J. Eric RobinsonAbstract:Fossiliferous organic sediments interstratified within fluvial gravels at Pennington Marshes, Lymington, have been recovered in boreholes and investigated. The organic deposit, here defined as the Pennington Organic Bed, occurs between −3.9 to −5.3 m OD and has been traced 200 m across the immediate area. Pollen analyses indicate a temperate flora of interglacial character. Molluscan and ostracod assemblages contain no brackish elements and are typical of a shallow, freshwater stream or abandoned channel. A change from an aquatic to a terrestrial molluscan fauna indicates progressive drying out of the water body. The Pennington Organic Bed cannot be confidently attributed to any particular stage, but since it occurs within a lower terrace than that at Stone Point, 15 km to the NE, it is probably younger and an early Ipswichian age (Ip Ha?) is suggested. The Pennington Lower Gravel, below the organic deposit, is therefore probably Wolstonian and the Pennington Upper Gravel, above them, Devensian in age. The estuarine interglacial deposits at Stone Point, previously believed to have been Ipswichian, are likely to belong to an earlier stage. It is possible, although less likely, that they accumulated during a later part of the Ipswichian as the transgression aggraded to the level of the higher terrace surface. Similarly, if the gravels at Stone Point resulted from a tributary river, rather than the Solent River itself, this could also explain the altimetric differences and allow the organic deposits to be attributed to different parts of the same stage. However, there is no evidence to support either of these alternative possibilities.
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Late Pleistocene deposits at Block Fen, Cambridgeshire, England
Journal of Quaternary Science, 1995Co-Authors: Richard Gilbert West, S. M. Peglar, M. E. Pettit, Richard C. PreeceAbstract:Organic sediments in a gravel quarry at Block Fen, Cambridgeshire, form a sheet dividing lower from upper gravels. Analyses of pollen, macroscopic plant remains and molluscs from these organic sediments are presented. They indicate the presence of temperate freshwater and slightly brackish fine floodplain sediments, which, on the basis of the palaeobotany, are correlated with the temperate Ipswichian Stage. The freshwater sediments, ascribed to Ipswichian substage IIb, occur at ca. −3 m OD. Marine-influenced tidal sediments, ascribed to Ipswichian substage III, occur at ca. −6 m OD. No evidence was found for the presence of more than one temperate stage in the sequence. The lower gravels are then correlated with the cold Wolstonian Stage and the upper gravels with the cold Devensian Stage. In contrast to the woodland environments indicated by the palaeobotany of the Ipswichian organic sediments, post-Ipswichian pollen diagrams and macroscopic plant remains in the upper suite of sands and gravels indicate open tree-less vegetation typical of the cold Devensian Stage. They also contain a typical cold-stage mollusc fauna. The sediments containing these floras and faunas are associated with thermal contraction cracks, indicating the presence of permafrost. The final sand and gravel aggradation in the Devensian forms the Block Fen Terrace, near 0 m OD. The evidence indicates that it is younger than the lacustrine sediments resulting from the blocking of the Fenland at the Wash by Late Devensian ice at ca. 18.5 ka BP. The sequence at Block Fen is related to nearby Ipswichian and Devensian sediments at Chatteris, March, Wimblington and Mepal, and to deposits at Wretton on the east margin of Fenland. The correlation permits an outline reconstruction of the history of the valley carrying the River Great Ouse between the Isle of Ely and the Chatteris and March ‘islands’ from the time of a gravel aggradation before the Ipswichian to the Flandrian. The reconstruction shows the time and level of the Ipswichian marine incursion into the Middle Level of Fenland and the extent of aggradation and erosion in the Devensian.
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Palaeontology and taphonomy of Late Quaternary fossil assemblages at Somersham, Cambridgeshire, England, and the problem of reworking
Journal of Quaternary Science, 1994Co-Authors: Richard Gilbert West, Richard C. Preece, K.l. Knudsen, David N. Penney, J. Eric RobinsonAbstract:Assemblages of foraminifers, ostracods and molluscs from temperate Ipswichian Stage (last temperate stage) sediments and overlying cold Devensian Stage (last cold stage) sediments at Somersham in the southern Fenland of Cambridgeshire have been analysed. The Ipswichian sediments contain faunas consistent with temperate brackish water conditions under tidal influence. The Devensian assemblages were recovered from a series of sands and gravels laterally accreting in a channel cutting into Ipswichian sediments. In contrast to the Ipswichian faunas, the faunas of particular Devensian samples show a complex mixture of temperate freshwater, brackish and marine taxa. The molluscs are mainly freshwater, with few land snails; they occur together with foraminifers and ostracods. Freshwater, brackish water and marine ostracods are present with foraminifers. A sample of Devensian fine laminated sediment in the channel was analysed for pollen; only abundant pre-Quaternary spores were present, with abundant foraminifers in the same sample. The taphonomy of the assemblages and the difficulties of their interpretation in environmental terms are discussed. The importance of taphonomy in assessing environments, climate, range of taxa and dating is stressed.
Richard Gilbert West - One of the best experts on this subject based on the ideXlab platform.
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Late Pleistocene temperate deposits in Lincolnshire, England and their implication for the history of the River Trent system
Quaternary International, 2020Co-Authors: Phil Gibbard, S. M. Peglar, Richard Gilbert WestAbstract:Abstract This article examines the interpretation and implications of Ipswichian (Eemian) Stage temperate deposits discovered by the British Geological Survey east of the Lincoln Gap in eastern England. The fluvial deposits underlie the Southrey Terrace at Coronation Farm, Southrey and The Hermitage, Stainfield in the River Witham valley. Previously unpublished palynological analyses indicate that the temperate deposits compliment published pollen, mollusc and coleopteran assemblages from the same localities. The deposit at Southrey represents Ipswichian (=Eemian) substages Ip IIb and III, whilst that at Stainfield represents the Ip IIb Substage. The combined sequences are compared to those at neighbouring localities in the Witham and Bain-tributary valleys at Tattershall Castle and Tattershall Thorpe. The implications of the correlation of the interglacial deposits provide a re-evaluation of the River Trent-Witham terrace sequence, demonstrating that the Southrey Terrace deposits are not the equivalent of the Late Wolstonian (=Saalian) Balderton Member, but the Middle Devensian (=Weichselian) Substage Fulbeck Member, upstream of Lincoln. This implies that the River Trent was potentially aligned northwards towards the Humber before the Ipswichian Stage interglacial. The revised correlation indicates that glaciation of the region did not occur in the Middle Wolstonian (MIS 8) but during the Late Wolstonian (MIS 6) Substage.
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Late and Middle Pleistocene deposits at Somersham, Cambridgeshire, U.K.: a model for reconstructing fluvial/estuarine depositional environments
Quaternary Science Reviews, 1999Co-Authors: Richard Gilbert West, John T Hollin, J. A. Catt, M. E. Pettit, K.l. Knudsen, David N. Penney, R. Andrew, C.p. Hart, G.f. Miller, Richard C. PreeceAbstract:Gravel quarries at Somersham, Cambridgeshire, have yielded evidence for a Pleistocene channel of the R. Great Ouse, containing temperate stage sediments between cold stage sediments. In the earlier cold stage, fluviatile gravels and floodplain loessic sediment accumulated. In the later cold stage a further series of gravel units and floodplain sediments were deposited, together with lake sediments. The lake sediments are associated with Lake Sparks, dammed by Late Devensian ice in the Wash at ca. 18.5 ka BP. The lake sediments overlie gravels with a radiocarbon date from an organic horizon indicating a Middle Devensian age. Clast lithological analyses from the earlier and later gravels suggest that reworking of gravels has occurred within a relatively stable catchment. The petrography of the earlier cold stage loessic sediment and temperate stage fine sediment indicates an Anglian affinity, which conflicts with the biostratigraphic interpretation. Pollen and macroscopic plant remains from sediments of both cold stages and from the temperate stage indicate, respectively, assemblages with a typical full-glacial aspect with a rich flora of shrubs and open ground herbs(including an assemblage at ca. 18 ka), and temperate freshwater and marine-influenced organic sediments. On the basis of pollen analysis these are ascribed to substages Ip II and III of the Ipswichian Stage(O.I.S. 5e), with a Pinus-Quercus-Corylus biozone in the former and a biozone with Carpinus in the latter. Marine-influenced sediments, at −3.7 to −0.3 m OD, indicate transgression in Ip II and regression in Ip III. Molluscan assemblages from the temperate stage and the later cold stage are described; two are from the Late Devensian, at a time near the maximum extension of ice into the Wash. Foraminifer and ostracod faunas are described from post-Ipswichian sediments and may be reworked. Radiocarbon dates confirm the age of the later gravel suite as Devensian and a calibration of the measurements is given. Amino acid ratios from Corbicula fluminalis valves from temperate stage sediments are reported, with measurements from different parts of the valve; the results tend to support an Ipswichian age. TL measurements of the earlier cold stage loessic sediment and associated sand indicate a pre-Ipswichian age for the sediments. The earlier cold stage is correlated with the pre-Ipswichian cold stage, the Wolstonian of Mitchell et al.(1973); problems with this correlation are discussed. Various periglacial phenomena, including thermal contraction networks and cracks, diapirs, involutions and coversand are associated with the Devensian sequence. The complex environmental history, based on stratigraphy and palaeontology, is described, and related to other nearby sites in southern Fenland.
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Late Pleistocene deposits at Block Fen, Cambridgeshire, England
Journal of Quaternary Science, 1995Co-Authors: Richard Gilbert West, S. M. Peglar, M. E. Pettit, Richard C. PreeceAbstract:Organic sediments in a gravel quarry at Block Fen, Cambridgeshire, form a sheet dividing lower from upper gravels. Analyses of pollen, macroscopic plant remains and molluscs from these organic sediments are presented. They indicate the presence of temperate freshwater and slightly brackish fine floodplain sediments, which, on the basis of the palaeobotany, are correlated with the temperate Ipswichian Stage. The freshwater sediments, ascribed to Ipswichian substage IIb, occur at ca. −3 m OD. Marine-influenced tidal sediments, ascribed to Ipswichian substage III, occur at ca. −6 m OD. No evidence was found for the presence of more than one temperate stage in the sequence. The lower gravels are then correlated with the cold Wolstonian Stage and the upper gravels with the cold Devensian Stage. In contrast to the woodland environments indicated by the palaeobotany of the Ipswichian organic sediments, post-Ipswichian pollen diagrams and macroscopic plant remains in the upper suite of sands and gravels indicate open tree-less vegetation typical of the cold Devensian Stage. They also contain a typical cold-stage mollusc fauna. The sediments containing these floras and faunas are associated with thermal contraction cracks, indicating the presence of permafrost. The final sand and gravel aggradation in the Devensian forms the Block Fen Terrace, near 0 m OD. The evidence indicates that it is younger than the lacustrine sediments resulting from the blocking of the Fenland at the Wash by Late Devensian ice at ca. 18.5 ka BP. The sequence at Block Fen is related to nearby Ipswichian and Devensian sediments at Chatteris, March, Wimblington and Mepal, and to deposits at Wretton on the east margin of Fenland. The correlation permits an outline reconstruction of the history of the valley carrying the River Great Ouse between the Isle of Ely and the Chatteris and March ‘islands’ from the time of a gravel aggradation before the Ipswichian to the Flandrian. The reconstruction shows the time and level of the Ipswichian marine incursion into the Middle Level of Fenland and the extent of aggradation and erosion in the Devensian.
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Late Pleistocene deposits at Chatteris, March and Wimblington, Cambridgeshire, UK
Proceedings of the Geologists' Association, 1995Co-Authors: Richard Gilbert West, S. M. Peglar, K.l. Knudsen, R. Andrew, M. E. PettitAbstract:Sites at Chatteris, March Town End and Wimblington Common have yielded evidence for Late Pleistocene vegetational history, sea-level change and gravel aggradation. Analysis of pollen, macroscopic plant remains and Foraminifera indicate that temperate freshwater and marine sediments were deposited in the Ipswichian Stage, substages II and HI. The freshwater sediments formed above 3.5 m OD, and the marine sediments from −3 m to 1.4 m OD. Gravel aggradations that followed contain reworked marine faunas, and include the so-called March Gravels. These are considered to be Devensian, and show a series of aggradations with heights declining during this cold stage. It is suggested that the term March Gravels be restricted to Devensian gravels, while the Ipswichian marine-influenced sediments are placed in a separate unit, the Wimblington Beds.
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Palaeontology and taphonomy of Late Quaternary fossil assemblages at Somersham, Cambridgeshire, England, and the problem of reworking
Journal of Quaternary Science, 1994Co-Authors: Richard Gilbert West, Richard C. Preece, K.l. Knudsen, David N. Penney, J. Eric RobinsonAbstract:Assemblages of foraminifers, ostracods and molluscs from temperate Ipswichian Stage (last temperate stage) sediments and overlying cold Devensian Stage (last cold stage) sediments at Somersham in the southern Fenland of Cambridgeshire have been analysed. The Ipswichian sediments contain faunas consistent with temperate brackish water conditions under tidal influence. The Devensian assemblages were recovered from a series of sands and gravels laterally accreting in a channel cutting into Ipswichian sediments. In contrast to the Ipswichian faunas, the faunas of particular Devensian samples show a complex mixture of temperate freshwater, brackish and marine taxa. The molluscs are mainly freshwater, with few land snails; they occur together with foraminifers and ostracods. Freshwater, brackish water and marine ostracods are present with foraminifers. A sample of Devensian fine laminated sediment in the channel was analysed for pollen; only abundant pre-Quaternary spores were present, with abundant foraminifers in the same sample. The taphonomy of the assemblages and the difficulties of their interpretation in environmental terms are discussed. The importance of taphonomy in assessing environments, climate, range of taxa and dating is stressed.
G.r. Coope - One of the best experts on this subject based on the ideXlab platform.
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Evidence for the early onset of the Ipswichian thermal optimum: palaeoecology of Last Interglacial deposits at Whittlesey, eastern England
Journal of the Geological Society, 2017Co-Authors: H. E. Langford, G.r. Coope, Steve Boreham, R.m. Briant, D.j. Horne, K.e.h. Penkman, D.c. Schreve, N.j. Whitehouse, J.e. WhittakerAbstract:Fossiliferous deposits infilling a channel at Whittlesey, eastern England, are dated by amino acid racemization to the Last Interglacial, and pollen analysis indicates deposition in Ipswichian biozones Ip Ib and Ip IIb. Multidisciplinary palaeoenvironmental analyses of these deposits provide a rare insight into Ip Ib subzone conditions. Specifically, the Ip Ib deposits contain exotic thermophiles Naias minor , Belgrandia marginata , Bembidion elongatum , Pelochares versicolor , Caccobius schreberi, Onthophagus massai and Emys orbicularis , usually associated with Ip IIb. Combined palaeotemperature reconstructions based on beetle, ostracod and vertebrate assemblages of the Ip Ib deposits indicate that summers (mean July range +19 to +22°C) were at least 2°C warmer than at present, whereas winters (mean January air temperature range 0 to +7°C) were probably similar to those of today. These palaeotemperature ranges encompass those for Ip IIb deposits at Trafalgar Square (+20 to +21°C and +1.5 to +3°C), previously considered the only Ipswichian site to record temperatures significantly warmer than Holocene temperatures. Of particular significance is that thermal optimal conditions commenced in Ip Ib, rather than being confined to Ip IIb. This demonstrates rapid warming and biological response to early Ipswichian climate amelioration, which accords with the deep-sea Last Interglacial and European Eemian records. Supplementary material: Supplementary Tables S1-S7 are available at http://doi.org/10.6084/m9.figshare.c.3830221.
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Table S7. Evidence for the early onset of the Ipswichian thermal optimum: palaeoecology of Last Interglacial deposits at Whittlesey, eastern England
2017Co-Authors: H. E. Langford, G.r. Coope, S. Boreham, R.m. Briant, D.j. Horne, K.e.h. Penkman, D.c. Schreve, N.j. Whitehouse, J.e. WhittakerAbstract:Table S7. Thermophile species in channel C and at other Ipswichian sites according to pollen biozonation
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Biostratigraphical distinction of interglacial coleopteran assemblages from southern Britain attributed to Oxygen Isotope Stages 5e and 7
Quaternary Science Reviews, 2001Co-Authors: G.r. CoopeAbstract:Abstract Beetle assemblages are described from 14 interglacial sites in southern England, all of which post-date the Hoxnian Interglacial (in the broad sense) and which can safely be attributed to Oxygen Isotope Stages 5e and 7. The beetle faunas from these interglacial deposits are large and complex and together include at least 387 named species many of which are no longer found living in the British Isles. Almost all of the latter have modern geographical distributions exclusively to the south of Britain and some are predominantly Mediterranean. A few have their nearest relatives living today in North Africa or as far away as northern India. Some of these temperate beetle assemblages are remarkably similar to one another especially in their inclusion of diagnostic exotic species. Others, though indicative of a temperate climate, exhibit consistent differences so that the 14 assemblages clearly divide themselves into two groups; Group (a) and Group (b), based on differences in their species composition and abundance. Group (a) beetle faunas, from seven sites, may be termed “classic” Ipswichian (Eemian) since they closely resemble the assemblage from the type site at Bobbitshole near Ipswich and have unimpeachable stratigraphical contexts. All of these faunas can with confidence be attributed to an early phase of Oxygen Isotope Sub-Stage 5e. Group (b) beetle faunas, also from seven sites, are very different in their specific composition and are more of a puzzle because they include some fossil assemblages from deposits that have, in the past, been attributed to the latter part of the Ipswichian Interglacial and others that are undoubtedly from stratigraphical deposits that are earlier than the Ipswichian and which have been correlated with Oxygen Isotope Stage 7. It is with the deposits yielding Group (b) faunas that the greatest controversy arises. On-line appendix available at http://www.elsevier.com/locate/quascirev
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A late Middle Pleistocene temperate–periglacial–temperate sequence (Oxygen Isotope Stages 7–5e) near Marsworth, Buckinghamshire, UK
Quaternary Science Reviews, 2001Co-Authors: Julian B. Murton, D Q Bowen, G.r. Coope, A.p. Currant, C.p. Green, M. H. Field, Andy Baker, Chris Caseldine, J. G. Evans, Jackie HattonAbstract:Abstract River-channel and colluvial deposits, near Marsworth, Buckinghamshire, record a temperate-periglacial-temperate sequence during the late Middle Pleistocene. The deposits of a lower channel contain tufa clasts bearing leaf impressions that include Acer sp., and Sorbus aucuparia and containing temperate arboreal pollen attributed to ash-dominated woodland. The tufa probably formed at the mouth of a limestone spring before being redeposited in a small river whose deposits contain plant remains, Mollusca, Coleoptera, Ostracoda and vertebrate bones of temperate affinities. The sediments, sedimentary structures and limited biological remains above the Lower Channel deposits indicate that fluvial deposition preceded climatic cooling into periglacial conditions. Fluvial deposition recurred during a later temperate episode, as shown by the mammalian bone assemblage in stratigraphically higher channel deposits. The Upper Channel deposits are confidently attributed to Oxygen Isotope Sub-Stage 5e (Ipswichian) on the basis of their vertebrate remains. However, the age of the Lower Channel deposits is less clear. The mammalian and coleopteran remains in the Lower Channel strongly suggest correlation with Oxygen Isotope Stage 7 on the basis of their similarities to other sites whose stratigraphy is better known and the clear difference of the Lower Channel assemblage from well-established faunas of Ipswichian or any other age. By contrast, U–Th dating of the tufa clasts suggests an age post 160 ka BP, while Aile/Ile ratios on Mollusca point to an Ipswichian age and younger. Four ways of interpreting this age discrepancy are considered, the preferred one correlating the Lower Channel deposits with Oxygen Isotope Stage 7.
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Sedimentology, palaeoecology and geochronology of Last Interglacial deposits from Deeping St James, Lincolnshire, England
Journal of Quaternary Science, 1999Co-Authors: D H Keen, Mark D Bateman, G.r. Coope, M. H. Field, H. E. Langford, J. S. Merry, Tim MighallAbstract:Pollen, plant macrofossil, molluscan and coleopteran data from organic muds below the low terrace of the River Welland at Deeping St James, Lincolnshire indicate deposition in the mixed oak forest phase of a Late Pleistocene interglacial. Coleopteran and molluscan data suggest summer temperatures up to 4°C warmer than at present in eastern England, and plant macrofossil material suggests a climate more continental than that of Britain in the Holocene. No direct analogue of this biota, however, exists currently in Europe. Biostratigraphical indications from the pollen coleoptera and Mollusca suggest an age in the Ipswichian Interglacial. Thermoluminescence dates between 120 ka and 75 ka and amino-acid ratios with a mean of 0.11 show that deposition of the sediments took place during Oxygen Isotope Stage 5. This accurate dating of a partial Ipswichian succession allows discussion of the ages of a number of other interglacial sites in eastern England of assumed Ipswichian age. Copyright © 1999 John Wiley & Sons, Ltd.
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Thames interglacial sites, Ipswichian sea levels and Antarctic ice surges
Boreas, 2008Co-Authors: John T HollinAbstract:New and old, pollen and other studies are summarized for seven sites in the Thames estuary, all of them most probably of last (Ipswichian) interglacial age. Early in the interglacial, at Crayford, Little Thurrock, and Purfleet, there was an aggradation of laminated (3 mm/pair) ‘brickearth’ (clay, with silt and sand), to above +11 m O.D. Observations in modern estuaries suggest that the laminations were of tidal origin, and related to a sea stand at +7 m, represented on the coast by e.g. the raised cliff at Brighton. In the middle of the Ipswichian, freshwater fossils at West Thurrock and Wretton (Norfolk) suggest that the sea fell below 0 m. Late in the Ipswichian, arguably at the break of climate, at Crayford, Ilford, Aveley, West Thurrock, Stutton (Suffolk) and probably Little Thurrock, there was an aggradation of massive brickearth (famous for its mammal remains) grading up into sand, to above + 14 m. The possibility is discussed that this second aggradation reflects a second rise of sea level, to +16 m, represented by e.g. the raised beach at Portland, and caused by an Antarctic ‘surge’. According to A. T. Wilson, this surge triggered the last (Devensian) ice age.
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Late and Middle Pleistocene deposits at Somersham, Cambridgeshire, U.K.: a model for reconstructing fluvial/estuarine depositional environments
Quaternary Science Reviews, 1999Co-Authors: Richard Gilbert West, John T Hollin, J. A. Catt, M. E. Pettit, K.l. Knudsen, David N. Penney, R. Andrew, C.p. Hart, G.f. Miller, Richard C. PreeceAbstract:Gravel quarries at Somersham, Cambridgeshire, have yielded evidence for a Pleistocene channel of the R. Great Ouse, containing temperate stage sediments between cold stage sediments. In the earlier cold stage, fluviatile gravels and floodplain loessic sediment accumulated. In the later cold stage a further series of gravel units and floodplain sediments were deposited, together with lake sediments. The lake sediments are associated with Lake Sparks, dammed by Late Devensian ice in the Wash at ca. 18.5 ka BP. The lake sediments overlie gravels with a radiocarbon date from an organic horizon indicating a Middle Devensian age. Clast lithological analyses from the earlier and later gravels suggest that reworking of gravels has occurred within a relatively stable catchment. The petrography of the earlier cold stage loessic sediment and temperate stage fine sediment indicates an Anglian affinity, which conflicts with the biostratigraphic interpretation. Pollen and macroscopic plant remains from sediments of both cold stages and from the temperate stage indicate, respectively, assemblages with a typical full-glacial aspect with a rich flora of shrubs and open ground herbs(including an assemblage at ca. 18 ka), and temperate freshwater and marine-influenced organic sediments. On the basis of pollen analysis these are ascribed to substages Ip II and III of the Ipswichian Stage(O.I.S. 5e), with a Pinus-Quercus-Corylus biozone in the former and a biozone with Carpinus in the latter. Marine-influenced sediments, at −3.7 to −0.3 m OD, indicate transgression in Ip II and regression in Ip III. Molluscan assemblages from the temperate stage and the later cold stage are described; two are from the Late Devensian, at a time near the maximum extension of ice into the Wash. Foraminifer and ostracod faunas are described from post-Ipswichian sediments and may be reworked. Radiocarbon dates confirm the age of the later gravel suite as Devensian and a calibration of the measurements is given. Amino acid ratios from Corbicula fluminalis valves from temperate stage sediments are reported, with measurements from different parts of the valve; the results tend to support an Ipswichian age. TL measurements of the earlier cold stage loessic sediment and associated sand indicate a pre-Ipswichian age for the sediments. The earlier cold stage is correlated with the pre-Ipswichian cold stage, the Wolstonian of Mitchell et al.(1973); problems with this correlation are discussed. Various periglacial phenomena, including thermal contraction networks and cracks, diapirs, involutions and coversand are associated with the Devensian sequence. The complex environmental history, based on stratigraphy and palaeontology, is described, and related to other nearby sites in southern Fenland.
D.c. Schreve - One of the best experts on this subject based on the ideXlab platform.
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Evidence for the early onset of the Ipswichian thermal optimum: palaeoecology of Last Interglacial deposits at Whittlesey, eastern England
Journal of the Geological Society, 2017Co-Authors: H. E. Langford, G.r. Coope, Steve Boreham, R.m. Briant, D.j. Horne, K.e.h. Penkman, D.c. Schreve, N.j. Whitehouse, J.e. WhittakerAbstract:Fossiliferous deposits infilling a channel at Whittlesey, eastern England, are dated by amino acid racemization to the Last Interglacial, and pollen analysis indicates deposition in Ipswichian biozones Ip Ib and Ip IIb. Multidisciplinary palaeoenvironmental analyses of these deposits provide a rare insight into Ip Ib subzone conditions. Specifically, the Ip Ib deposits contain exotic thermophiles Naias minor , Belgrandia marginata , Bembidion elongatum , Pelochares versicolor , Caccobius schreberi, Onthophagus massai and Emys orbicularis , usually associated with Ip IIb. Combined palaeotemperature reconstructions based on beetle, ostracod and vertebrate assemblages of the Ip Ib deposits indicate that summers (mean July range +19 to +22°C) were at least 2°C warmer than at present, whereas winters (mean January air temperature range 0 to +7°C) were probably similar to those of today. These palaeotemperature ranges encompass those for Ip IIb deposits at Trafalgar Square (+20 to +21°C and +1.5 to +3°C), previously considered the only Ipswichian site to record temperatures significantly warmer than Holocene temperatures. Of particular significance is that thermal optimal conditions commenced in Ip Ib, rather than being confined to Ip IIb. This demonstrates rapid warming and biological response to early Ipswichian climate amelioration, which accords with the deep-sea Last Interglacial and European Eemian records. Supplementary material: Supplementary Tables S1-S7 are available at http://doi.org/10.6084/m9.figshare.c.3830221.
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Table S7. Evidence for the early onset of the Ipswichian thermal optimum: palaeoecology of Last Interglacial deposits at Whittlesey, eastern England
2017Co-Authors: H. E. Langford, G.r. Coope, S. Boreham, R.m. Briant, D.j. Horne, K.e.h. Penkman, D.c. Schreve, N.j. Whitehouse, J.e. WhittakerAbstract:Table S7. Thermophile species in channel C and at other Ipswichian sites according to pollen biozonation
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Sedimentology, palaeontology and archaeology of late Middle Pleistocene River Thames terrace deposits at Purfleet, Essex, UK
Quaternary Science Reviews, 2002Co-Authors: D.c. Schreve, David R Bridgland, Peter Allen, Jeff J Blackford, Christopher P Gleed-owen, Huw I Griffiths, David H Keen, Mark J WhiteAbstract:Middle Pleistocene fluvial deposits of the Corbets Tey Formation at Purfleet, Essex, provide evidence of an un-named and previously poorly recognized interglacial, thought to corrrelate with Oxygen Isotope Stage (OIS) 9. Previous attributions of the sediments to the Ipswichian (Last Interglacial) Stage are refuted. New investigations have yielded rich molluscan, mammalian and ostracod assemblages that indicate fully temperate conditions and the distal influence of marine transgression. Pollen analyses suggest a previously unrecorded phase of interglacial vegetational development. Clast composition, geomorphological evidence and the occurrence of molluscs that favour large rivers all point to deposition by the Thames, rather than in a minor tributary, as suggested previously. Three separate Palaeolithic industries in stratigraphical superposition are recognized at Purfleet, these being Clactonian, Acheulean and Levallois. Purfleet is therefore a key locality in the understanding of the early human occupation and exploitation of southern Britain, as well as for the interpretation and correlation of the terrace sequence in the Thames Valley
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Differentiation of the British late Middle Pleistocene interglacials: the evidence from mammalian biostratigraphy
Quaternary Science Reviews, 2001Co-Authors: D.c. SchreveAbstract:Abstract Acknowledgement of the climatic complexities of the marine oxygen isotope (δ18O) record has inspired fresh investigations into methods of identifying and separating interglacial deposits on land. Biostratigraphical analysis of fossil mammalian assemblages, particularly those from long fluvial sequences, has proved to be a uniquely valuable technique in the differentiation of the various temperate episodes of the late Middle Pleistocene in Britain, thereby enabling a sequence of diagnostic mammalian assemblage-zones to be established. The scheme has provided an important means of correlation between geographically-distant localities and between different types of depositional environment. Using mammalian biostratigraphical information, this paper explores the evidence for three post-Anglian interglacials prior to the Last (Ipswichian) Interglacial, correlated with Stages 11, 9 and 7 of the oxygen isotope record, and presents the case for the recognition of much smaller-scale environmental and climatic oscillations within these interglacials, possibly corresponding to marine isotopic substages.