Figures and tables
Figures
(Figure 1.1) Map of southern and central England, showing the division into the catchments of the modern Thames, Severn and Trent rivers. As is described in the text, the area to the north-west of the Cotswolds escarpment was probably drained by the Thames in the Early Pleistocene. In the early Middle Pleistocene it was drained by the Trent system (the proto-Soar of Shotton, 1953).
(Figure 1.2) The oxygen isotope record, as represented in a borehole (Site 607) in the mid-Atlantic at latitude c. 41°N. Numbered stages are shown at the top; even-numbered ones are relatively cold (more ice) and odd-numbered ones relatively warm (less ice). Note that the amplitude and wavelength of the curve increases at around 0.7 million years ago (the δ18O scale is a ratio obtained by comparing the proportion of 18O to 16O in samples to that in a mean sea-water standard). Compiled from data published by Ruddiman et al. (1989).
(Figure 1.3) Longitudinal profiles of Thames terrace surfaces throughout the area covered by the present volume. The main sources of information used in the compilation of this diagram are as follows: Arkell (1947a, 1947b), Briggs and Gilbertson (1973), Briggs et al. (1985), Evans (1971) and Sandford (1924, 1926) for the Upper Thames; Gibbard (1985) and Sealy and Sealy (1956) for the Middle Thames; Bridgland (1983a, 1988a) and Bridgland et al. (1993) for the Lower Thames and eastern Essex; Whiteman (1990) for central Essex.
(Figure 1.4) Map showing the locations of the GCR sites described in this volume.
(Figure 2.1) The gravels of the Upper Thames catchment.
(Figure 2.2) Idealized transverse section through the terrace deposits of the Upper Thames (Evenlode).
(Figure 2.3) Longitudinal profiles of the Upper Thames terrace deposits. Compiled from the following sources: Arkell (1947a, 1947b); Bishop (1958); Briggs and Gilbertson (1973); Briggs et al. (1985); Evans (1971); Kellaway et al. (1971); Sandford (1924, 1926); Tomlinson (1929).
(Figure 2.4) Map (A) and section (B) showing the location of the Sugworth channel and its relation to other channel features revealed during the construction of the A34 road cutting (after Shotton et al., 1980).
(Figure 2.5) Section through the Sugworth Channel Deposits in the east abutment for the Sugworth Lane overbridge (after Shotton et al., 1980).
(Figure 2.6) Map showing the course of the hypothetical Severn—Thames river of the Early Pleistocene.
(Figure 2.7) Map of the Long Hanborough area, showing the location of the GCR site. The quarry in the top left part of the diagram is Duke's Pit.
(Figure 2.8) The east face at Long Hanborough Gravel Pit (after Briggs and Gilbertson, 1973). This shows 'frost boils'/decalcification pipes, filled with pebbly loam. Note the effects of frost heaving in the adjacent bedding.
(Figure 2.9) Sections at Long Hanborough photographed early in this century. This view was first published in the Witney Geological Survey memoir, where it was attributed to Duke's Pit. Note the prominent 'frost boil'/pipe features, filled with darker material. Upward deformation of the gravel bedding adjacent to the left-hand pipe is clearly shown. Photograph reproduced by courtesy of the British Geological Survey (A3188).
(Figure 2.10) Map of Wolvercote brick pit and the surrounding area, showing the possible alignment of the Wolvercote Channel.
(Figure 2.11) Section through the Wolvercote Channel (after Sandford, 1924). now an ornamental lake surrounded by residential development, making reinvestigation difficult. Temporary exposures in the channel deposits were recently observed on the eastern side of the pit (Briggs et al., 1985; Tyldesley, 1986b), but attempts to locate the channel in a railway cutting immediately to the west revealed only Oxford Clay with pockets of gravel at the surface (Bridgland and Harding, 1986). Work is continuing in open areas close to the brick pit to locate further remnants of the fossiliferous sediments, if any exist. So far no GCR site has been identified at Wolvercote, but it is hoped that future investigations will reveal Wolvercote Channel Deposits at a potentially conservable location.
(Figure 2.12) Idealized section through the Summertown-Radley Formation.
(Figure 2.13) A comparison of sections recorded at Magdalen Grove, by (A) Sandford (1924) and (B) Briggs et al. (1985).
(Figure 2.14) Section in the Stanton Harcourt Channel Deposits, showing in situ mammoth remains. Note that both Pleistocene and Jurassic bivalves are visible, the latter (Gryphaea sp.) scattered on the exhumed Oxford Clay surface as well as within the gravel. (Photo: S. Campbell.)
(Figure 2.15) Composite section through the deposits at Stanton Harcourt (after Briggs et al., 1985).
(Figure 2.16) Section at Stanton Harcourt, showing an intraformational ice-wedge structure in the Stanton Harcourt Gravel. The complexity of this feature is typical of such structures at this site (see text). (Photo: D.J. Briggs.)
(Figure 2.17) Hand-axe from Stanton Harcourt, discovered by Mr V. Griffin, the excavator driver. Some 26.9 cm long, this is believed to be the third-largest hand-axe discovered to date in Britain (MacRae, 1987). (Photo: R.J. MacRae.)
(Figure 2.18) Comparison of terrace stratigraphy upstream (A) and downstream (B) from the limit of the Kempton Park Formation. Numbers 2-8 indicate oxygen isotope stages.
(Figure 3.1) (Following two pages) Map showing the gravels of the Middle Thames, the Vale of St Albans and the Kennet valley. Compiled, with reinterpretation as indicated in the text, from the following sources: Cheshire (1986a), Gibbard (1985), Green and McGregor (1978a), Hare (1947), Hey (1965, 1980), Sealy and Sealy (1956), Thomas (1961), Wooldridge (1927a) and the Geological Survey's New Series 1:50,000 and 1:63,360 maps. GCR sites and type localities are shown.
(Figure 3.2) Idealized transverse section through the classic Middle Thames sequence of the Slough-Beaconsfield area. The stratigraphical position of the Rassler Gravel, not preserved in this area, is shown.
(Figure 3.3) Long-profiles of terrace formations in the Middle Thames. Compiled predominantly from data provided by Gibbard (1985), with subordinate information from Sealy and Sealy (1956) and Thomas (1961). Modifications to the source information are described in the text.
(Figure 3.4) Map showing Wooldridge's reconstructed courses of the Thames and its tributary, the Mole–Wey. The distribution of Pebble Gravel remnants is also shown; those remnants in which Greensancl chert is scarce are distinguished from those in which it is relatively common.
(Figure 3.5) Contours on the base of the Red Crag. The positions of sites on the Chilterns and North Downs that may correlate with the Red Crag are shown (after Moffat and Catt, 1986b).
(Figure 3.6) Long-profile diagram of higher deposits in the Middle Thames and the Vale of St Albans, showing the North London Pebble Gravels, attributed in this volume to deposition by a south-bank tributary of the early Thames.
(Figure 3.7) The stratigraphy of the deposits at Priest's Hill, Nettlebed, as recorded from a temporary section. The position of the pollen profile is shown (after Horton, 1983).
(Figure 3.8) Pollen from the organic silts at Nettlebed (after Turner, 1983).
(Figure 3.9) Section in the north face of Westmill Quarry, recorded in June 1981 (after Cheshire, 1983b).
(Figure 3.10) Palaeodrainage during key phases of the Anglian evolution of the Vale of St Albans (from Cheshire, 1986a): (A) During deposition of the Westmill Lower Gravel; (B) During the existence of the Watton Road lake; (C) During the existence of the Moor Mill lake; (D) At the maximum extent of the Ware Till ice; (E) At the maximum extent of the Stortford Till ice; (F) At the maximum extent of the Ugley Till ice; (G) During the deposition of the Westmill Upper Gravel and the Smug Oak Gravel; (H) During the Westmill Till ice advance.
(Figure 3.11) Section in the south face of Moor Mill Quarry, recorded in July 1972 (after Gibbard, 1978d).
(Figure 3.12) Detail of laminated lake beds at Moor Mill Quarry. (Photo: P.L. Gibbard.)
(Figure 3.13) Section at Hamstead Marshall Gravel Pit, showing the three divisions of the Silchester Gravel at this site, as described in the text (numbers apply to description). Note that the boundary between divisions 1 and 2 cuts across the sedimentary bedding. Also note central ground-ice/solution structure (after Chartres et al., 1976).
(Figure 3.14) Map showing the various sites at Furze Platt and their relation to the Pleistocene geology.
(Figure 3.15) The GCR section excavated at Cannoncourt Farm Pit in April 1987. For location, see Fig. 3.14.
(Figure 3.16) Photograph taken in 1913 of Mr George (Deify) Carter working at Cannoncourt Farm Pit, sieving gravel. The digging and sorting of gravel by hand, before mechanization, resulted in frequent discoveries of palaeoliths. Mr Carter found many of the artefacts in the collections from Cannoncourt Farm Pit, including the 32 cm specimen (Figure 3.17a) that remains the largest from Britain. (Photo: L. Treacher, reproduced by courtesy of J.J. Wymer.)
(Figure 3.17) Hand-axes from Cannoncourt Farm Pit: drawings originally published by Laraine (1940). (a) The extraordinarily large pointed hand-axe found by Mr G. Carter in March 1919. This was acquired by L. Treacher and donated by him to the Natural History Museum. (b) A fine example of a 'ficron' hand-axe.
(Figure 3.18) Diagrammatic representation of the relations between the Boyn Hill and Lynch Hill Gravels and the Langley Silt Complex. The types of Palaeolithic artefacts that characterize each deposit are shown. Also illustrated is the interpretation of these deposits by King and Oakley (1936).
(Figure 3.19) Composite section at Brimpton, showing the stratigraphical relations of the various deposits and the locations of samples of biostratigraphical significance (modified from Bryant et al., 1983).
(Figure 3.20) Pollen from the deposits at Brimpton (after Bryant et al., 1983).
(Figure 4.1) The Pleistocene deposits of the Lower Thames (after Bridgland, 1988a).
(Figure 4.2) Longitudinal profiles of terrace deposits in the Lower Thames.
(Figure 4.3) Idealized transverse section through the terraces of the Lower Thames. The odd-numbered (warm) oxygen isotope stages to which the various interglacial deposits are attributed are indicated (numbers in circles). The stratigraphical position of the Trafalgar Square deposits is shown.
(Figure 4.4) Section in Hornchurch Railway Cutting, recorded during its original construction (after Holmes, 1892a).
(Figure 4.5) The GCR section, Hornchurch Railway Cutting, 1983. Pecked horizontal rulings denote steps in the section. The cutting side slopes at approximately 45° (see (Figure 4.6)).
(Figure 4.6) The GCR section, Hornchurch Railway Cutting, 1983. The Boyn Hill/Orsett Heath Gravel occupies the upper part of the section, its base occurring on the step beneath the tree root. The remainder of the visible section is in till, although London Clay was reached in the base of the excavation. (Photo: P. Harding.)
(Figure 4.7) Long profile projections of the Black Park and Boyn Hill Formations between the Middle and Lower Thames. The correlation with the Westmill Upper Gravel of the Lea basin is also shown.
(Figure 4.8) Contrasting interpretations of the sediments at Dartford Heath: (A) hypothetical and idealized section, after Cornwall (1950); (B) a composite section based on observations of exposures in Wansunt Pit (after Chandler and Leach, 1912). Bed numbers used in the description section are indicated.
(Figure 4.9) Map of the Swanscomhe skull site and adjacent areas.
(Figure 4.10) Exposure in the Swanscombe Lower Gravel and Lower Loam, GCR Section 1 (see Fig. 4.9), opened in October 1982 but photographed the following winter. The section has been sampled for clast-lithological analysis and palaeontological studies. Articulated bivalves are visible in the upper part of the Lower Gravel. (Photo: D.R. Bridgland.)
(Figure 4.11) Exposure in the Swanscombe Lower Loam, Lower Middle Gravel, Upper Middle Gravel and Upper Loam, GCR Section 2 (see Fig. 4.9), October 1982. The Lower Loam, exposed in a pit (see Fig. 4.15) at the base of the main section, has been sampled for studies of micromorphology. The shovel is standing on the top of the Lower Middle Gravel (see also Fig. 4.12). (Photo: P. Harding.)
(Figure 4.12) The sequence at Swanscombe. based on the exposures excavated by the GCR Unit in 1982 (after Bridgland et al., 1985).
(Figure 4.13) Section through the terrace deposits at Swanscombe. The notation follows the description section in the text.
(Figure 4.14) Animal footprints in the top of the Swanscombe Lower Loam (1972). (Photo: A.J. Sutcliffe.)
(Figure 4.15) Photograph of buried soil in the upper part of the Swanscombe Lower Loam. (Photo: D.R. Bridgland.)
(Figure 4.16) The two most characteristic molluscan species of the so-called 'Rhenish' fauna from Swanscombe: (A) Theodoxus serratiliniformis (Geyer); (B) Viviparus diluvianus (Kunth). Scale bars graduated in mm. (Photos: Department of Zoology, University of Cambridge).
(Figure 4.17) Map of the Swanscombe–Northfleet area, showing the locations of the various Pleistocene localities.
(Figure 4.18) (A) Map showing the location of the various exposures at Purfleet; (B) the extent of the Thames floodplain in the Purfleet area during the deposition of the Corbets Tey Gravel. Note that where the floodplain passed through the Chalk outcrop of the Purfleet Anticline it was considerably restricted.
(Figure 4.19) Section excavated in the Esso Pit by the GCR Unit in 1986. * Artefacts from the sandy gravel immediately overlying the Chalk are as follows (numbered on the figure): (1) undiagnostic sharp flake; (2) large preparation flake in sharp condition; (3) small cortical flake that may have formed naturally in the river's bed load; (4) undiagnostic hard-hammer flake in slightly rolled condition; (5) broken flake (the break probably occurred at the time of knapping); (6) broken unstained flake that may have formed naturally in the river's bed load; (7) core, utilizing a broken nodule — approximately four flakes have been removed by alternate flaking; (8) small sharp flake that may have formed naturally in the river's bed load; (9) a sharp flake, thick in section (particularly towards the distal end), with semi-converging scars on the dorsal surface — flakes of this type are produced during the shaping of hand-axes. Other material was found elsewhere at the site. The collection has been lodged with the British Museum. Archaeological determinations by P. Harding.
(Figure 4.20) Idealized section through the terrace deposits at Purfleet (modified from Hollin, 1977). Bed 1 contains Clactonian artefacts.
(Figure 4.21) Map showing the various sites in the Thurrock-Grays area.
(Figure 4.22) The GCR sections at Globe Pit.
(Figure 4.23) Section through the Pleistocene deposits in the area of Globe Pit (after Wymer, 1985b).
(Figure 4.24) GCR Section 2 at Globe Pit, showing bedded gravel extending to below 10 m O.D. (looking north). The surveying staff rests on the exhumed Thanet Sand surface. (Photo: P. Harding.)
(Figure 4.25) Section through the deposits of the Mucking Formation revealed in a road cutting in 1983–4.
(Figure 4.26) (A) Plan and (B) section, Lion Pit tramway cutting, showing the relative positions of the GCR sections and the relations of the various deposits.
(Figure 4.27) Lion Pit tramway cutting [no caption]
(Figure 4.28) Photograph of Section 1 at the Lion Pit tramway cutting. (Photo: P. Harding.)
(Figure 4.29) Excavations at the base of Section 1, Lion Pit tramway cutting. The two layers of coarse flint near the base of the fluviatile deposits are clearly seen, above a potholed surface cut in coombe rock. The Lion Pit Palaeolithic industry occurs in these coarse layers. The material in the top right of the view is made ground. (Photo: P. Harding.)
(Figure 4.30) Flint artefacts from the 1984 GCR excavation at the Lion Pit tramway cutting. (A) Large broken flake (length 9 cm). The butt (at the top of the view) is faceted, showing evidence of the preparation of the striking platform (this cannot be seen in this dorsal view). At least five scars from previous flaking can be seen. The sharp condition is typical of material from the site. (B) Tortoise core (height 12 cm). This is a classic Levallois core from which a large flake has been detached, thus removing the central part of the 'tortoise', which was formed by radiating flake scars. By preparing a core of this type, a flake of predetermined shape and size has been removed (Levallois technique). (C) Single platform core with refitted flake (height of core plus flake 15.5 cm). The flake, found separately in the gravel, was produced during the shaping of the core. The presence of refitting material at the site is important evidence for the occurrence of knapping debris in a primary context. The striking platform of the core is at the top of the view. (D) The same core as in C, without the refitted flake (height 14 cm). (Photos by Elaine A. Wakefield.)
(Figure 4.31) Section through the deposits of the Mucking Formation at Sandy Lane Quarry, Aveley (modified from Hollin, 1977).
(Figure 4.32) The discovery of elephant skeletons at Aveley in 1964. (A) View of the working face in the Sandy Lane pit in 1964, during the excavation of the skeletons. The site was worked from west to east, so this view was taken looking towards the north-east. The excavation was located at approximately [TQ 552 808]. (B) Close-up view, showing the mammoth bones at the higher level in the background and the straight-tusked elephant bones, at a lower stratigraphical level, in the foreground. (Photos: A.J. Sutcliffe.)
(Figure 4.33) North—south section through the terrace deposits at Ilford. Compiled from published records, as shown. Note that information on the base levels of the Pleistocene deposits is generally lacking.
(Figure 4.34) Plan of the surviving remnants of the Baker's Hole Complex, Northfleet. A—C are the three parts of the GCR site. Updated information regarding the location of the original Baker's Hole site (and the possibility that sediments related to this survive at D) has been supplied by F.F. Wenban-Smith (pers. comm.).
(Figure 4.35) Section at the original Baker's Hole site (after Dewey, 1932).
(Figure 4.36) Early records from Northfleet sketches of the original Baker's Hole site. (A) Map showing the location of the quarry known as 'Baker's Hole' and of the section there that yielded Palaeolithic artefacts, drawn by F.N. Haward in 1910. Reproduced by courtesy of the British Museum, London. (B) Measured drawing by F.N. Haward of the section on the west side of 'Newbarn Pit (Baker's Hole)' as seen in 1906, although the drawing is dated November 1920. The locations of artefact discoveries are indicated. (Reproduced by courtesy of the Natural History Museum, London). Thanks are due to F.F. Wenban-Smith, who drew the author's attention to the existence of these archival records, and S. Parfitt, who discovered the section drawing.
(Figure 4.37) Section excavated at Northfleet (B, (Figure 4.34)) by the British Museum (after Kerney and Sieveking, 1977). This is believed to coincide with Burchell's main 'Ebbsfleet Channel' section. Numbers refer to the description in the text.
(Figure 4.38) Section excavated at Northfleet (A, (Figure 4.34)) by the British Museum (after Kerney and Sieveking, 1977).
(Figure 5.1) Pleistocene geology of Essex, showing the various types of gravel described in this chapter, the extent of the Anglian till sheet and the relation of these to the existing drainage systems (modified from Bridgland, 1988a).
(Figure 5.2) Pleistocene gravels of the Tendring Plateau (after Bridgland, 1988a).
(Figure 5.3) Idealized N—S transverse section through the Pleistocene deposits of the Tendring Plateau (after Bridgland, 1988a).
(Figure 5.4) Palaeodrainage of eastern Essex up to the Anglian glaciation (after Bridgland, 1988a): (A) Palaeodrainage at the time of deposition by the Medway of the Claydons and Daws Heath Gravels, part of the Rayleigh Hills gravels. The Thames and Medway are thought to have had separate routes to the North Sea at this time. (B) Palaeodrainage at the time of deposition by the Medway of the Oakwood and Ashingdon Gravels. The Waldringfield Gravel, which might be a correlative of the Ashingdon Gravel, is also shown. It is believed that the Thames and Medway joined during Waldringfield Gravel times, but this confluence is believed to have been situated to the east of the present coastline. (C) Palaeodrainage at the time of deposition by the Thames of the Ardleigh Gravel. (D) Palaeodrainage at the time of deposition by the Thames of the Wivenhoe Gravel. (E) Palaeodrainage during the early Anglian Stage, prior to the inundation of the Thames valley by the Lowestoft Till ice sheet. (F) Palaeodrainage during the Anglian glaciation, prior to the diversion of the Thames but after its valley became blocked by ice. The highly distinctive Upper St Osyth and Upper Holland Gravels were laid down at this time.
((Figure 5.5) Palaeodrainage of Essex following the Anglian glaciation (modified from Bridgland, 1988a). (A) Palaeodrainage during the filling of the Southend/Asheldham/Clacton Channel. The Swanscombe Lower Gravel Channel and the Cudmore Grove Channel are both thought to be lateral equivalents. The Rochford Channel is now thought to represent an overdeepened section of the same feature (see text). This channel was excavated in the late Anglian by the newly diverted Thames and filled during the Hoxnian Stage (sensu Swanscombe). (B) Palaeodrainage during the deposition of the Southchurch/Asheldham Gravel.. This aggradational phase is believed to have culminated during the earliest part of the Saalian Stage, early in Oxygen Isotope Stage 10. (C) Palaeodrainage during the filling of the Shoeburyness Channel. The channel beneath the Corbets Tey Gravel of the Lower Thames is believed to be an upstream equivalent of this feature. It is thought that both the excavation and filling of the channel were intra-Saalian events, dating from Oxygen Isotope Stages 10 and 9 respectively. (D) Palaeodrainage during the deposition of the Barling Gravel. This is regarded as an intra-Saalian deposit, aggraded during Oxygen Isotope Stage 8. (E) Palaeodrainage during the deposition of the Mucking Gravel of the Lower Thames. The Thames-Medway equivalent of this formation is buried beneath the coastal alluvium east of Southend and can be traced offshore (Bridgland et ed., 1993). This aggradational phase occurred towards the end of the complex Saalian Stage, culminating early in Oxygen Isotope Stage 6. (F) Palaeodrainage during the last glacial. The submerged valley of the Thames-Medway has been recognized beneath Flandrian marine sediments in the area offshore from eastern Essex (after D'Olier, 1975).
(Figure 5.6) Idealized stratigraphical sequence through the Pleistocene deposits at Newney Green (after Whiteman, 1990).
(Figure 5.7) 'Patterned ground' at the top of the Kesgrave Group gravel at Newney Green, as exhumed from beneath the Lowestoft Till by quarrying. The pattern results from the polygonal distribution of sand wedges in the Barham Soil (see text). (Photo: P. Allen.)
(Figure 5.8) Section excavated in 1988 at the Newney Green GCR site.
(Figure 5.9) Idealized Pleistocene sequence at Ardleigh (after Bridgland et al., 1988).
(Figure 5.10) The Ardleigh interglacial deposits exposed above Ardleigh Lower Gravel in a drainage channel in the floor of Martells Quarry, Ardleigh (1987). (Photo: D.R. Bridgland.)
(Figure 5.11) Plan and sections showing the distribution and geometry of the Little Oakley Silts and Sands (after Bridgland et al., 1988).
(Figure 5.12) Characteristic Mollusca from the Little Oakley Silts and Sands. (A) Tanousia cf. stenostoma (Nordmann); (B) Sphaerium solidum (Normand); (C) Valvata naticina Menke; (D) Unio crassus Philipsson; (E) Belgrandia marginata (Michaud). A, C and E are scanning electron micrographs. Scale bars are graduated in mm. (Photos: Department of Zoology, University of Cambridge.)
(Figure 5.13) Section at Wivenhoe, showing the organic clay (modified from Bridgland et al., 1988)
(Figure 5.14) Stylized block diagram showing the stratigraphical relations of the Lower and Upper St Osyth and Holland Gravels.
(Figure 5.15) The gravels of eastern Essex (after Bridgland, 1988a).
(Figure 5.16) Idealized transverse section through the gravels of the Southend area (modified from Bridgland, 1988a).
(Figure 5.17) Map showing the distribution of Pleistocene deposits in the region of Clacton and the location of the various sites mentioned in the text.
(Figure 5.18) Section through the Clacton area, showing the various Clacton Channel occurrences (modified from Warren, 1955).
(Figure 5.19) Section through the fill of the main Clacton Channel, as exposed at the West Cliff (modified from Warren, 1955).
(Figure 5.20) Photograph of the second archaeological excavation at Clacton, taken in 1970. The Clacton Channel Gravel is clearly seen, beneath calcareous silt (marl). London Clay forms the floor of the excavated area; careful removal of the overlying gravel has revealed undulations in its surface, probably scour features. (Photo: J.J. Wymer.)
(Figure 5.21) Flint flake from the West Cliff at Clacton, found in situ in GCR Section 4 in April 1987, at c. 9.9 m O.D. This flake was lying immediately below the wedge of blue-grey clay, interpreted as the feather-edge of the Clacton Channel Deposits. This is probably the highest point at which an artefact has been found in the Clacton deposits, although stratigraphically it was at the same level as the earlier Palaeolithic finds. (Drawing by P. Harding.)
(Figure 5.22) SW–NE section through the deposits at East Mersea, showing the relations of the Cudmore Grove Channel to the Blackwater deposits at the Hippopotamus and Restaurant Sites. Points A and B are indicated on (Figure 5.23).
(Figure 5.23) Map showing the Pleistocene deposits of East Mersea (after Bridgland et al., 1988). The points A and B refer to the ends of the section in (Figure 5.22). Point C is the location of the section in (Figure 5.24).
(Figure 5.24) Section through the Cudmore Grove Channel Deposits, located at Point C on (Figure 5.23).
(Figure 5.25) GCR excavation at Cudmore Grove, May 1987, which coincided with a field excursion of the Geologists' Association (Bridgland et al., 1988). A pit has been dug into the fossiliferous sequence beneath the beach. The natural exposure of the layer of compressed wood is visible in the foreground and the Mersea Island Gravel is superbly exposed in the cliffs. (Photo: AJ. Sutcliffe.)
(Figure 5.26) Part of a fossil tree protrudes from beneath the beach at Cudmore Grove. An interesting analogue is provided by the modern tree, which has fallen over the cliffs from the rapidly diminishing grove, a victim of the rapid coastal erosion. (Photo: A.J. Sutcliffe.)
(Figure 5.27) Idealized transverse section through Mersea Island (after Bridgland et al., 1988) .
(Figure 5.28) Map showing the outcrop of the Asheldham Gravel and bedrock surface contours, revealing the form of the Asheldham Channel (modified from Lake et al., 1977).
(Figure 5.29) Section at Goldsands Pit. This shows the division into upper and lower gravels, separated by cross-bedded and ripple-laminated sands.
(Figure 5.30) Section excavated at the Maldon GCR site in March 1984. Beds 1–3 are illustrated (see Description).
(Figure 5.31) Flint hand-axe from Maldon Railway Cutting, found during the GCR excavations. The artefact is a cordate hand-axe of Wymer's (1968) type J, having a symmetrical shape with a cutting edge around the entire circumference. The implement has a white surface patina and is slightly rolled, although with rather more severe damage of the edges. Both sides show a network of incipient thermal fractures. (Drawing and description by P. Harding).
(Figure 5.32) Longitudinal profiles of Blackwater terrace gravels.
(Figure 5.33) Excavations at the East Mersea Restaurant Site. This view, looking north-east, shows bones being collected from the channel deposits temporarily exposed in a trench dug through the beach. Only London Clay is exposed on the foreshore. (Photo: A.J. Sutcliffe.)
(Figure 5.34) Sections at: (A) the East Mersea Restaurant Site; and (B) the Cudmore Grove Hippopotamus Site.
(Figure 5.35) East Mersea Hippopotamus Site: an elephant tooth is shown protruding from a silty pocket in the London Clay foreshore. All the faunal remains from this site have been recovered from similar situations, thought to represent pockets at the base of the Restaurant Gravel (see text). (Photo: A.J. Sutcliffe.)
(Figure 5.36) Mammalian bones from Great Totham (R. Wrayton collection). (A) Molar tooth of mammoth (Mammuthus primigenius). (B) Tusk of mammoth (Mammuthus primigenius). (C) Lower jaw of woolly rhinoceros (Coelodonta antiquitatis). (D) Humerus of woolly rhinoceros (Coelodonta antiquitatis). (E) Vertebra of horse (Equus ferus). (F) Fragment of jaw of spotted hyaena (Crocuta crocuta). Scale bars are graduated in cm. (Photos: R. Wrayton).
(Figure 5.37) Small vertebrate remains from Great Totham. The identifiable species represented are pike (Esox lucius), perch (Perca fluviatilis), stickleback (Gasterosteus aculeatus) and frog (Rana sp.; probably R. temporaria, common frog). Remains of a cyprinid fish (carp family) and indeterminate newt are also present. Identifications by B. Clarke (Amphibia) and A. Wheeler (fish) of the Natural History Museum. Scale bar is graduated in mm, numbered in cm. (Photo: Paul Douthwaite.)
(Figure 5.38) Pollen from the organic deposits at Great Totham.
Tables
(Table 1.1) Correlation of Quaternary deposits within the Thames system. Rejuvenations that have occurred since the Anglian glaciation are indicated.
(Table 2.1) Lithostratigraphical classification of Upper Thames deposits.
(Table 2.2) Stratigraphical interpretation of the Upper Thames deposits advocated in this volume.
(Table 2.3) Stratigraphical subdivisions of the Summertown-Radley Formation.
(Table 3.1) Correlation of tributary and main Thames formations within the Pebble Gravel Group and other pre-diversion gravels in the Middle Thames and Vale of St Albans regions.
(Table 3.2) Clast-lithological data (in percentage of total count) from the Middle Thames and Vale of St Albans (compiled from various sources). The data concentrates on key sites, GCR sites and localities mentioned in the text. Note that many different size ranges are included and that these yield strikingly different data (this can be observed where results from different fractions from the same deposits have been analysed). As in (Table 4.2), (Table 5.1) and (Table 5.3), the igneous category includes metamorphic rocks (very rarely encountered) and the quartzite category includes durable sandstones. The Tertiary flint category comprises rounded pebbles (sometimes subsequently broken) reworked from the Palaeogene (see glossary with (Table 4.2)).
(Table 3.3) Post-Winter Hill terraces and gravel formations in the Middle Thames and Kennet valleys.
(Table 3.4) Stratigraphy of the Thatcham Terrace deposits at Brimpton (after Bryant et al., 1983).
(Table 4.1) The Pleistocene fluvial sequence in the Lower Thames (first published usage of lithostratigraphical terms in reference given in parentheses), with proposed correlations with the Middle Thames sequence, Pleistocene stages and oxygen isotope stages.
(Table 4.2) Clast-lithological data from the Lower Thames. All counts by the author, at 16–32 mm size range, except those in italics, which are 11.2–16 mm counts. Note that non-durables (including Chalk) are excluded from the calculations, but Chalk is shown in this table as a relative % of the total durables.
(Table 5.1) Lithostratigraphy of fluvial gravels in Essex.
(Table 5.2) Clast-lithological composition of the gravels described in Chapter 5, Part 1.
(Table 5.3) Correlation of gravel formations in Essex within the Kesgrave Group with deposits in other areas.
(Table 5.4) The Pleistocene sequence at Newney Green (after Rose et al., 1978; Whiteman, 1990; see also (Figure 5.6)).
(Table 5.5) Clast-lithological composition of gravels described in Chapter 5, Parts 2 and 3.
(Table 5.6) Gravel formations in eastern Essex.
(Table 5.7) Ostracods from Great Totham (identifications by T. Allen).
(Table 5.8) Plant macrofossils from Lofts Farm Pit, Great Totham (identifications by M. Pettit).
References