Limits...
Differentiation of MIS 9 and MIS 11 in the continental record: vegetational, faunal, aminostratigraphic and sea-level evidence from coastal sites in Essex, UK.

Roe HM, Coope GR, Devoy RJ, Harrison CJ, Penkman KE, Preece RC, Schreve DC - Quat Sci Rev (2009)

Bottom Line: However, the sites can be differentiated on the basis of mammalian biostratigraphy, new aminostratigraphic data, as well as the differences in the sea-level history.The infill of a much later channel, yielding non-marine molluscs and vertebrates including Hippopotamus, appears to have formed during the Ipswichian (MIS 5e).This evidence is compared with other important sites of late Middle Pleistocene age in Britain and elsewhere on the continent and the importance of a multidisciplinary approach is stressed.

View Article: PubMed Central - PubMed

Affiliation: School of Geography, Archaeology and Palaeoecology, Queen's University of Belfast, Belfast BT7 1NN, UK.

ABSTRACT
Multidisciplinary investigations of the vegetational, faunal and sea-level history inferred from the infills of buried channels on the coast of eastern Essex have a direct bearing on the differentiation of MIS 11 and MIS 9 in continental records. New data are presented from Cudmore Grove, an important site on Mersea Island that can be linked to the terrace sequence of the River Thames. The vegetational history has been reconstructed from a pollen sequence covering much of the interglacial represented. The temperate nature of the climate is apparent from a range of fossil groups, including plant remains, vertebrates (especially the rich herpetofauna), molluscs and beetles, which all have strong thermophilous components. The beetle data have been used to derive a Mutual Climatic Range reconstruction, suggesting that mean July temperatures were about 2 degrees C warmer than modern values for southeast England, whereas mean January temperatures may have been slightly colder. The sea-level history has been reconstructed from the molluscs, ostracods and especially the diatoms, which indicate that the marine transgression occurred considerably earlier in the interglacial cycle than at the neighbouring Hoxnian site at Clacton. There are a number of palynological similarities between the sequence at Cudmore Grove and Clacton, especially the presence of Abies and the occurrence of Azolla filiculoides megaspores. Moreover, both sites have yielded Palaeolithic archaeology, indeed the latter is the type site of the Clactonian (flake-and-core) industry. However, the sites can be differentiated on the basis of mammalian biostratigraphy, new aminostratigraphic data, as well as the differences in the sea-level history. The combined evidence suggests that the infill of the channel at Cudmore Grove accumulated during MIS 9, whereas the deposits at Clacton formed during MIS 11. The infill of a much later channel, yielding non-marine molluscs and vertebrates including Hippopotamus, appears to have formed during the Ipswichian (MIS 5e). This evidence is compared with other important sites of late Middle Pleistocene age in Britain and elsewhere on the continent and the importance of a multidisciplinary approach is stressed.

No MeSH data available.


Palaeodrainage maps of eastern Essex during MIS 11 (a) and MIS 9 (b). Map a) shows the tidally-influenced Thames–Medway flowing between Tillingham (East Hyde) and Clacton during the late-temperate sub-stage of the inferred MIS 11 interglacial. The sequence at Swanscombe is considered to be the upstream equivalent of this channel system (Bridgland, 1994; Roe and Preece, 1995). Map b) depicts a larger, more complex palaeo-estuary inferred for the end of the early-temperate sub-stage of the younger interglacial, when lower estuarine conditions prevailed at Cudmore Grove (after Roe, 1994; Schreve et al., 2002). The Cudmore Grove palaeo-channel is placed in the more northerly part of this estuarine system and is assumed to have formed a tributary of the main Thames–Medway estuary. The dark shading shows the distribution of channel-fill sediments of estuarine character which have been examined for pollen and other microfossils (Roe, 1994).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2806946&req=5

fig12: Palaeodrainage maps of eastern Essex during MIS 11 (a) and MIS 9 (b). Map a) shows the tidally-influenced Thames–Medway flowing between Tillingham (East Hyde) and Clacton during the late-temperate sub-stage of the inferred MIS 11 interglacial. The sequence at Swanscombe is considered to be the upstream equivalent of this channel system (Bridgland, 1994; Roe and Preece, 1995). Map b) depicts a larger, more complex palaeo-estuary inferred for the end of the early-temperate sub-stage of the younger interglacial, when lower estuarine conditions prevailed at Cudmore Grove (after Roe, 1994; Schreve et al., 2002). The Cudmore Grove palaeo-channel is placed in the more northerly part of this estuarine system and is assumed to have formed a tributary of the main Thames–Medway estuary. The dark shading shows the distribution of channel-fill sediments of estuarine character which have been examined for pollen and other microfossils (Roe, 1994).

Mentions: Further independent support for a separation of the Cudmore Grove interglacial beds from those at Clacton is provided by the marked differences in the sea-level histories of the two sites. The Clacton Channel deposits do not record the onset of estuarine/marine conditions until relatively late in the interglacial, during the late-temperate sub-stage (Ho IIIb), whereas the earlier part of the channel-fill sequence, representing the early-temperate sub-stage, accumulated in a freshwater environment (Turner and Kerney, 1971; Bridgland et al., 1999). A similar onset of marine conditions, again during Ho IIIb, is recorded in the channel-fill sequences at East Hyde near Tillingham (Roe, 2001) (Fig. 11) and at Swanscombe (Kerney, 1971) and all three channels are believed to have infilled during MIS 11 (Bridgland et al., 1999; Roe, 2001; Fig. 12a). At Cudmore Grove, in contrast, estuarine conditions were already established in the early-temperate sub-stage of the interglacial represented, and relative sea levels remained high until at least the late-temperate sub-stage. It is difficult to reconcile the presence of outer estuarine conditions at Cudmore Grove during the early-temperate sub-stage with the freshwater conditions at Clacton; the channels lie at approximately the same height and are only 10 km apart and are thus likely to have been flooded by the sea around the same time had they formed during the same interglacial (Roe, 1994). To accommodate these differences within the same temperate event requires a complex model of coastal evolution, which would have allowed the sea to penetrate the eastern part of Mersea Island, but not neighbouring Clacton (Roe, 1999). Whilst this cannot be ruled out, it is not supported by any evidence or the bio- and aminostratigraphical data.


Differentiation of MIS 9 and MIS 11 in the continental record: vegetational, faunal, aminostratigraphic and sea-level evidence from coastal sites in Essex, UK.

Roe HM, Coope GR, Devoy RJ, Harrison CJ, Penkman KE, Preece RC, Schreve DC - Quat Sci Rev (2009)

Palaeodrainage maps of eastern Essex during MIS 11 (a) and MIS 9 (b). Map a) shows the tidally-influenced Thames–Medway flowing between Tillingham (East Hyde) and Clacton during the late-temperate sub-stage of the inferred MIS 11 interglacial. The sequence at Swanscombe is considered to be the upstream equivalent of this channel system (Bridgland, 1994; Roe and Preece, 1995). Map b) depicts a larger, more complex palaeo-estuary inferred for the end of the early-temperate sub-stage of the younger interglacial, when lower estuarine conditions prevailed at Cudmore Grove (after Roe, 1994; Schreve et al., 2002). The Cudmore Grove palaeo-channel is placed in the more northerly part of this estuarine system and is assumed to have formed a tributary of the main Thames–Medway estuary. The dark shading shows the distribution of channel-fill sediments of estuarine character which have been examined for pollen and other microfossils (Roe, 1994).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2806946&req=5

fig12: Palaeodrainage maps of eastern Essex during MIS 11 (a) and MIS 9 (b). Map a) shows the tidally-influenced Thames–Medway flowing between Tillingham (East Hyde) and Clacton during the late-temperate sub-stage of the inferred MIS 11 interglacial. The sequence at Swanscombe is considered to be the upstream equivalent of this channel system (Bridgland, 1994; Roe and Preece, 1995). Map b) depicts a larger, more complex palaeo-estuary inferred for the end of the early-temperate sub-stage of the younger interglacial, when lower estuarine conditions prevailed at Cudmore Grove (after Roe, 1994; Schreve et al., 2002). The Cudmore Grove palaeo-channel is placed in the more northerly part of this estuarine system and is assumed to have formed a tributary of the main Thames–Medway estuary. The dark shading shows the distribution of channel-fill sediments of estuarine character which have been examined for pollen and other microfossils (Roe, 1994).
Mentions: Further independent support for a separation of the Cudmore Grove interglacial beds from those at Clacton is provided by the marked differences in the sea-level histories of the two sites. The Clacton Channel deposits do not record the onset of estuarine/marine conditions until relatively late in the interglacial, during the late-temperate sub-stage (Ho IIIb), whereas the earlier part of the channel-fill sequence, representing the early-temperate sub-stage, accumulated in a freshwater environment (Turner and Kerney, 1971; Bridgland et al., 1999). A similar onset of marine conditions, again during Ho IIIb, is recorded in the channel-fill sequences at East Hyde near Tillingham (Roe, 2001) (Fig. 11) and at Swanscombe (Kerney, 1971) and all three channels are believed to have infilled during MIS 11 (Bridgland et al., 1999; Roe, 2001; Fig. 12a). At Cudmore Grove, in contrast, estuarine conditions were already established in the early-temperate sub-stage of the interglacial represented, and relative sea levels remained high until at least the late-temperate sub-stage. It is difficult to reconcile the presence of outer estuarine conditions at Cudmore Grove during the early-temperate sub-stage with the freshwater conditions at Clacton; the channels lie at approximately the same height and are only 10 km apart and are thus likely to have been flooded by the sea around the same time had they formed during the same interglacial (Roe, 1994). To accommodate these differences within the same temperate event requires a complex model of coastal evolution, which would have allowed the sea to penetrate the eastern part of Mersea Island, but not neighbouring Clacton (Roe, 1999). Whilst this cannot be ruled out, it is not supported by any evidence or the bio- and aminostratigraphical data.

Bottom Line: However, the sites can be differentiated on the basis of mammalian biostratigraphy, new aminostratigraphic data, as well as the differences in the sea-level history.The infill of a much later channel, yielding non-marine molluscs and vertebrates including Hippopotamus, appears to have formed during the Ipswichian (MIS 5e).This evidence is compared with other important sites of late Middle Pleistocene age in Britain and elsewhere on the continent and the importance of a multidisciplinary approach is stressed.

View Article: PubMed Central - PubMed

Affiliation: School of Geography, Archaeology and Palaeoecology, Queen's University of Belfast, Belfast BT7 1NN, UK.

ABSTRACT
Multidisciplinary investigations of the vegetational, faunal and sea-level history inferred from the infills of buried channels on the coast of eastern Essex have a direct bearing on the differentiation of MIS 11 and MIS 9 in continental records. New data are presented from Cudmore Grove, an important site on Mersea Island that can be linked to the terrace sequence of the River Thames. The vegetational history has been reconstructed from a pollen sequence covering much of the interglacial represented. The temperate nature of the climate is apparent from a range of fossil groups, including plant remains, vertebrates (especially the rich herpetofauna), molluscs and beetles, which all have strong thermophilous components. The beetle data have been used to derive a Mutual Climatic Range reconstruction, suggesting that mean July temperatures were about 2 degrees C warmer than modern values for southeast England, whereas mean January temperatures may have been slightly colder. The sea-level history has been reconstructed from the molluscs, ostracods and especially the diatoms, which indicate that the marine transgression occurred considerably earlier in the interglacial cycle than at the neighbouring Hoxnian site at Clacton. There are a number of palynological similarities between the sequence at Cudmore Grove and Clacton, especially the presence of Abies and the occurrence of Azolla filiculoides megaspores. Moreover, both sites have yielded Palaeolithic archaeology, indeed the latter is the type site of the Clactonian (flake-and-core) industry. However, the sites can be differentiated on the basis of mammalian biostratigraphy, new aminostratigraphic data, as well as the differences in the sea-level history. The combined evidence suggests that the infill of the channel at Cudmore Grove accumulated during MIS 9, whereas the deposits at Clacton formed during MIS 11. The infill of a much later channel, yielding non-marine molluscs and vertebrates including Hippopotamus, appears to have formed during the Ipswichian (MIS 5e). This evidence is compared with other important sites of late Middle Pleistocene age in Britain and elsewhere on the continent and the importance of a multidisciplinary approach is stressed.

No MeSH data available.