Fenland Basin Research Articles

Pleistocene glaciation of Fenland, England, and its implications for evolution of the region.

Detailed investigation of landforms and their underlying deposits on the eastern margin of Fenland, East Anglia, demonstrated that they represent a series of glaciofluvial delta-fan and related sediments. Associated with these deposits are glacially dislocated sediments including tills, meltwater and pre-existing fluvial sediments. These ‘Skertchly Line’ deposits occur in the context of a substantial ice lobe that entered Fenland from the N to NE, dammed the streams entering the basin and caused glacial lakes to form in the valleys on the margins. Bulldozing by the ice lobe caused a series of ice-pushed ridges to form at the dynamic margin, especially at the ice maximum and during its retreat phases. Meltwater formed a series of marginal fans that coalesced into marginal accumulations in the SE of the basin. The ice lobe is named the Tottenhill glaciation. Further investigations of the Fenland margin have revealed the extent of the Tottenhill glaciation in the Fenland Basin, to the south and west, in sufficient detail to demonstrate the nature of the Tottenhill ice lobe and the landscape left on deglaciation. The ice lobe is likely to have been prone to surging. This is indicated by the low gradient of the ice lobe, the presence of underlying ductile Mesozoic clays, the evidence of ice-marginal flooding and the presence of arcuate glaciotectonic push moraines. Regional correlation, supported by independent numerical geochronology, indicates that the glaciation occurred ca 160 ka, i.e. during the late Middle Pleistocene, Marine Isotope Stage (MIS) 6, the Wolstonian Stage. Comparison and correlation across the southern North Sea Basin confirms that the glaciation is the equivalent of that during the Late Saalian Drenthe Stadial in The Netherlands. The implications of this correlation are presented. Before the glaciation occurred, the Fenland Basin did not exist. It appears to have been initiated by a subglacial tunnel valley system beneath the Anglian (=Elsterian, MIS 12) ice sheet. During the subsequent Hoxnian (=Holsteinian; approx. MIS 11) interglacial, the sea invaded the drainage system inherited following the glacial retreat. The evolution through the subsequent ca 200 ka Early to Middle Wolstonian substages, the interval between the Hoxnian (Holsteinian) temperate Stage and the Wolstonian glaciation, represents a period during which fluvial and periglacial activity modified the landscape under cold climates, and organic sediments were laid down during a warmer event. Palaeolithic humans were also periodically present during this interval, their artefacts having been reworked by the subsequent glaciation. The deglaciation was followed by re-establishment of the rivers associated with the deposition of Late Wolstonian (Warthe Stadial) gravels and sands, and later, deposits of the Ipswichian interglacial (=Eemian, approx. MIS 5e) including freshwater, then estuarine sediments. Subsequent evolution of the basin occurred during the Devensian Stage (=Weichselian, MIS 5d-2) under predominantly cold, periglacial conditions.

Late Middle Pleistocene glaciofluvial sedimentation in western Norfolk, England

AbstractInvestigation of landforms on the eastern margin of the East Anglian Fenland basin has demonstrated that they represent a series of glaciofluvial delta-fan and related sediment accumulations (the Skertchly Line) deposited at the margin of an ice-lobe that entered the depression. This ‘Tottenhill glaciation’ dated to ca 160 ka, or the late Wolstonian (= late Saalian) Stage, is equivalent to that during the Netherlands' Drenthe Substage (Marine Isotope Stage 6). Of these landform complexes, an additional site at Shouldham Thorpe, previously nominated as the stratotype for deposits linked to a pre-Anglian Stage, Midlands'-derived Ingham/‘Bytham river’, has now been studied. Examination of the internal structure and form of the feature, using ground-penetrating radar (GPR), supported by section logging, borehole records, local landscape morphology and previous description, together indicate that the deposits rest on an eroded surface of Lowestoft Formation diamicton (Anglian Stage) and must therefore be of post-, rather than pre-Anglian age. The investigations indicate that the Shouldham deposits were laid down as a glacio-marginal subaerial (‘terminoglacial’) fan at the ice-front. In common with other sequences in the Skertchly Line complexes, deposition at Shouldham Thorpe was accompanied by minor ice-front movement, this fan potentially being deposited before retreat to the Tottenhill locality. The implications of the results are discussed.

The Quaternary history of the Wash fluvial network, UK

This paper appraises and compares the Middle–Upper Pleistocene sedimentary sequences preserved in the fluvial systems draining into the Fenland Basin and the Wash estuary. Of the main Fenland rivers the longest records, which extend back to the initial Anglian (glacial) formation of the basin, are found in the Great Ouse and its tributaries, particularly the Cam and the Nar. These sequences preserve sediments representing all four post-Anglian interglacials. The Nene also has an extensive post-Anglian history, with evidence for a Hoxnian estuary that is presumed to have been the precursor of the Wash. North of the Nene, however, the Welland and Witham (proto-Trent) have relatively short sequences, which are thought to commence with a later (post-Anglian–pre-Devensian) glaciation that affected Lincolnshire and fed the previously-recognized Tottenhill outwash delta south of Kings Lynn. Prior to Devensian deglaciation the Witham valley was occupied by the Trent, which was the trunk river of the late Middle Pleistocene Wash system. During periods of low sea level the river would have extended north-eastwards across what is now the floor of the North Sea, possibly via the Inner Silver Pit. Several of the central Fenland sequences show evidence of infrequent terrace formation during the late Quaternary, although this might in part be due to poor vertical separation between terraces, so that differentiating them has been difficult; this has been exacerbated by mixed biostratigraphical signals due to the preservation of sediments representing more than one interglacial beneath a single terrace surface. In several of the systems there is evidence for valley rejuvenation to the lowest terrace or valley-floor level during the MIS 4–3 transition. The observed differences within what, during the predominant periods of lower sea level, would have been a single Wash river system are difficult to explain.

Interglacial Extreme Floods and Their Implications for Climate Instability in the Ipswichian (Eemian) Stage for the River Great Ouse, Southeast England, U.K.

Abstract This paper outlines a sedimentological study of an extreme flood event for the Last Interglacial or the Ipswichian (Eemian) Stage. A channeled bedrock surface and associated fossiliferous diamicton deposits occur below the Ipswichian floodplain alluvium at Woolpack Farm and the adjacent area in the lower middle reach of the River Great Ouse, southeast England. Detailed geological observations suggest that these features were derived from an extreme flood event, probably connected to an exceptionally large storm surge from the North Sea. The waves accompanying the surge not only caused deep entrenchment of the ground but also entrained and transported the brackish-water gastropod Mercuria confusa to the southern margins of the Fenland basin, to an elevation about 2.5 m above the normal marine to brackish influence in this region. At the recession stage, cohesive debris flows developed, emplacing in the scoured channels diamicton deposits containing numerous tree and animal remains. The catastrophic impact exerted by the flood on the landscape has led to its preservation in the bedrock. In comparison with modern storm surges and in light of the absence of comparable geological features in the Holocene, the flood must have been far greater in magnitude, a response to intensified atmospheric circulation perturbation under unstable atmospheric or climatic conditions during the thermal maximum of the Ipswichian at circa 125 ka. Stable climatic conditions probably developed afterwards as indicated by the subsequent accretion of thick argillaceous alluvium characteristically under frequent, relatively low-amplitude flood conditions.

Climatic control on Quaternary fluvial sedimentology of a Fenland Basin river, England

AbstractUnderstanding and interpreting climate response from ancient fluvial deposits requires a combined approach of detailed sedimentological description and interpretation, local climate proxies, and the accurate comparison of these sequences with further independent climate records. Application of these multiple lines of evidence is particularly effective in the Quaternary Period, where higher resolution and more detailed palaeoenvironmental reconstruction are possible. This paper presents results from a Devensian (Weichselian) age sequence in northern Fenland, England, that integrates these approaches. Detailed sedimentological description has identified three fluvial facies associations overlain by a period of ice‐wedge cast formation. Fossil plant and coleopteran material within these sediments have been studied to provide palaeoenvironmental reconstructions for the local landscape, including quantitative temperature estimates using the mutual climatic range method on fossil Coleoptera. In addition, joint application of radiocarbon and optically stimulated luminescence (OSL) dating allows this sequence to be compared with the stacked marine isotope record, although dates do not agree well at the limit of the radiocarbon technique. Sedimentological interpretations, palaeoenvironments and global ice‐volume variations (a proxy for climatic severity) are all in agreement and show clearly how the River Nene responded to subtle changes in climate and vegetation cover during the Devensian (Weichselian) Stage. The level of detail possible in this reconstruction shows the importance of this approach in understanding fluvial response to past climate changes.

Breeding biology of the Golden Oriole Oriolus oriolus in the fenland basin of eastern Britain

This paper describes, for the first time, aspects of the breeding biology of the British Golden Oriole population. The Golden Oriole population in the fenland basin of East Anglia became established in 1967 and since the early 1980s the annual breeding population has varied from about 20 to 35 pairs. Males arrived in mid-May, and females about a week later. Nest building starts about five days after female arrival. Mean date for first egg laying was around 1 June. The mean clutch size was 3.53. Observed incubation periods were 18 to 19 days. Mean hatching date was 18 June, and the mean brood size at seven days was 2.60. Nestling periods were from 13 to 15 days, and the mean fledging date was 3 July. Failed clutches may be replaced; no evidence was found for genuine second broods. Estimated mean productivity of all nests including failures was 1.4–2.0 fledgings per nest. The greatest cause of failure was bad weather in June, and nests produced three times as many fledged young in warm dry Junes as in cool wet ones. The breeding habitat is very strongly associated with plantations of early leafing hybrid Black Poplars Populus nigra. A total of 94.2% of all nests found were in these trees, and since 1987 this figure has risen to 100%. The mean height of the nests in poplars was about 7 m below the top of the tree, irrespective of the height of the tree. Most nests were in the north, northeast or east sectors of the tree, and 80% were within two trees of the edge of the woodland. Breeding densities were generally at or below 0.25 pairs/km2, but up to 2.25 pairs/km2. Nestling diet contains many Poplar-feeding Lepidoptera and a surprising number of Bumblebees. Conservation efforts should aim to produce more areas of Poplar woodland with plenty of woodland edges and with 30 ha/km2 of Poplar plantation.

On the minimum amplitude of regional sea-level fluctuations during the Flandrian

The mathematical form of a time–height sea-level curve representing intermediate-frequency fluctuations superimposed on an underlying upward trend yields a simple method for estimating the minimum amplitude of fluctuations from field measurements of the thickness of silt–peat couplets. Drawing on data from the Thames Estuary and the Fenland Basin, fluctuations of relative sea-level with minimum amplitudes between 0.08 m and 0.91 m seem to have occurred in the southeast British region during the mid-Flandrian. © 1997 John Wiley & Sons, Ltd.

The Holocene lithostratigraphy of Fenland, eastern England: a review and suggestions for redefinition

AbstractThe Fenland basin is filled with unconsolidated Holocene marine and freshwater deposits. Stratigraphic studies of the basin date back to 1877. This paper reviews the various lithostratigraphic schemes which have been proposed. Particular attention is paid to the presently accepted lithostratigraphy. Examples and a case study of a newly surveyed area are used to highlight its failings. Many of the difficulties experienced in Fenland are common to problems of lithostratigraphic classification in coastal lowland environments, as is demonstrated by reference to recent debate in the southeastern North Sea. In Fenland, as a result of the shortcomings of the various schemes, it is proposed that a new lithostratigraphy with formal stratotypes is devised. Suggestions are made as to the form this new stratigraphy could take. In the meantime, an informal lithostratigraphy should be adopted which has no regional or chronostratigraphic connotations.

Flandrian pollen profiles from the Nar Valley, Norfolk (Great Britain): An analysis of deteriorated pollen percentages using consolidation pressures

Deteriorated pollen percentages have been recorded from Flandrian Fenland sediments at two sites in the Nar Valley, Norfolk. The use of compression data from a soil mechanics technique, the oedometer test, has important bearing on the interpretation of the amount and types of deteriorated pollen encountered in the pollen stratigraphy of the sediments. In particular, it is shown that the amorphous category of deterioration does not appear to be related to physical pressures but increases in importance where corroded grains also become significant. Further oedometer tests are required on samples from different areas with different stress histories within and outside the Fenland basin to ascertain whether such trends are consistent features.

The Origin of the Fenland Meres: Fenland Homologues of the Norfolk Broads

AbstractA section from the extinct waterway of the Little Ouse to the former Red Mere in west Suffolk is described, which shows that the lake mans succeed the clay flanges extending from the roddon silts. Thus the Fenland Meres formed in the course of the Coastal or Upper Silts transgression of the Fenland Basin, during which raised banks of silt were built along the tidal waterways, and these ponded back the fresh water. The Meres are shown to be roughly similar in age and manner of formation to the Norfolk Broads.

Studies of the post-glacial history of British vegetation - III. Fenland polen diagrams - IV. Post-glacial changes of relative land- and sea-level in the English Fenland

Since 1932 the Cambridge Fenland Research Committee has been engaged in solving the problem of the history of the deposits of the Fenland basin, by the many methods appropriate to the archaeologists, geologists, geographers and botanists who make up that body. Since so large a part of the Fenland basin is filled with peat or with alternating beds of peat or silt, a study of vegetational development in the area has inevitably meant co-ordination of botanical work with that of specialists in other subjects, and has led, in itself, to a study of Fenland stratigraphy. In the two preceding papers of this series an account has been given of the stratigraphy of the southern part of the Fenlands, so far as this has been determinable by study of the lateral continuity of peat and other beds, by observations on the remains of organisms in them, and by correlation with archaeological indices (Godwin and Clifford 1938). In these papers comparatively little reference has been made to the results of pollen analysis, and it is with the application of this method to studies of Fenland deposits that the present paper is concerned. It purposes to add another type of evidence for the correlation of fen beds, and to show that this evidence both confirms and extends the results previously described.

Studies of the post-glacial history of British vegetation I. Origin and stratigraphy of Fenland deposits near Wooldwalton, Hunts II. Origin and stratigraphy of deposits in southern Fenland

The fenland basin of East Anglia is a shallow depression centred round the Wash and filled with extensive post-glacial deposits of peat or of estuarine silt and clay. The alternation of these deposits, and changes in their character, are the record of a complex history of climatic alteration, marine transgression and regression, and of vegetational evolution. The Fenland Research Committee, founded in 1932, has for its object the elucidation of this history, which is of importance not only intrinsically, but in relation also to the post-glacial history of the adjoining margin of western Europe, to the history of human settlement in Britain, and to the theory of peat stratigraphy and vegetational history in this country. Results of intensive investigations at fenland sites of particular archaeological interest have already been published: they represent the correlated research of specialists in several sciences. The first paper dealing principally with peat stratigraphy and vegetational history was that of the present authors on the deposits at Wood Fen, near Ely (H. and M. E. Godwin and M. H. Clifford 1935). They now report the results of more extensive observations of similar character in another portion of the fenland basin where the deposits have a wider range of character and of age.

Archaeology of the Submerged Land-Surface of the Essex Coast

Collectors of prehistoric antiquities have long regarded the foreshore of long stretches of the Essex Coast between the rivers Stour and Blackwater as a prolific hunting ground, and many notable collections, consisting mainly of flints, have been obtained from this area. It is not the purpose of this paper to record these discoveries in detail, but rather to discuss the circumstances under which the antiquities are found, to summarise the main facts relating to the age of the old land-surface now submerged below the sea at high tide, and in conclusion to relate the facts observed on the Essex Coast to the stratigraphy established for the post-glacial deposits of the Fenland basin.

The Fenland Frontier in Anglo-Saxon England

It would seem that the Anglo-Saxon invasion of a great part of eastern Britain in the fifth century radiated fan-wise from the gateway of the Wash and of the Fenland Gulf. If this is true, it is not surprising. The position of the continental base of the Anglo-Saxons made the area a natural entry into the Midland plain; and the invaders, with the Wash behind them, gazed upon no unfamiliar scene. The region into which they came may not have been so different from their former homeland on the flats of northern Germany, the homeland which Bede tells us they had so completely deserted. They penetrated by way of the Fenland rivers, up the Nene, the Welland, the Ouse, and the Witham, and this big spread was supplemented to the north and to the south by the smaller river entrances, the Bure, the Yare, the Waveney, the Humber and so on. The archaeological finds, as plotted by Mr Thurlow Leeds, are located along the courses of navigable streams and their tributaries, and are disposed concentrically around the Fenland. Dr Cyril Fox has moreover indicated affinities, during the earlier Saxon period, between the opposite shores of this marshy gulf. All had changed, however, when the tribes emerged into the light of history. The Fenland basin, characterized at an earlier epoch by a certain cultural unity, had now become a frontier region, separating peoples and exercising a repelling action revealed in the making of the Anglo-Saxon States. Kingdoms, finding their limits here, partitioned the marshy wastes between them, and the barrier of the Fens became a permanent feature in the political geography of the Anglo-Saxon Heptarchy.