Bridgland, D.R. 1994. Quaternary of the Thames. Geological Conservation Review Series No. 7. JNCC, Peterborough, ISBN 0 412 48830 2.
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D.R. Bridgland
Globe Pit provides important evidence that contributes to the stratigraphical record of the Lower Thames terrace sequence and, in particular, to the parallel record of Palaeolithic occupation in southern Britain. A gravel here, the feather-edge of the Lynch Hill/Corbets Tey Formation, yields a prolific Clactonian industry. The occurrence of this industry, which has been regarded as 'early' within the Lower Palaeolithic, within deposits formerly ascribed to the 'Middle Terrace', has long been regarded as anomalous. The fact that hand-axes occur at higher-level sites such as Swanscombe has given rise to interpretations of the Lower Thames sequence involving complex fluctuations of base level. Consideration of the relations between these artefact-bearing deposits and fossiliferous sediments elsewhere in this and other terrace aggradations suggests that the gravel at Globe Pit is indeed slightly later than the Swanscombe sequence, probably dating from the latter part of Oxygen Isotope Stage 10 (early Saalian).
Globe Pit is the first of two sites in the Grays area, a district famous for the fossiliferous Pleistocene brickearth (a mixture of silts, sands and clays) that was exploited there until early in the present century. Two main spreads of brickearth appear on the Geological Survey map (Sheet 271) in the vicinity of Grays, one at West Thurrock and the other at Little Thurrock
The brickearth of the Grays area has generally been associated with the 'Middle Terrace' of the Lower Thames, mapped by the Geological Survey as 'Taplow Gravel', but now recognized as Corbets Tey Gravel and correlated with the Lynch Hill Formation of the Middle Thames (Bridgland, 1988a; Gibbard et al., 1988). The term brickearth is in this instance applied to well-bedded, often laminated, fluviatile silts and fine sands with subordinate clay (West, 1969; Hollin, 1977).
The brickearth and associated gravels at Grays (Little Thurrock) have been studied by numerous workers over more than one and a half centuries. Early contributions included those of Morris (1836), Wood (1848), Jones (1850), Wood Jun. (1866a, 1867, 1868, 1872), Dawkins (1867), Tylor (1869), Hughes (in Whitaker, 1889, p. 420), Woodward (1890), Reid (1897), Hinton and Kennard (1900) and Dewey et al(1924). A full list of previous literature describing the area was given by Hinton and Kennard (1900), much of which refers to faunal remains found in the brickearth. Of particular importance were sections in a pit south of Orsett Road, in which a highly fossiliferous lenticular bed of fine sand yielded abundant remains of molluscs and small vertebrates (Hinton and Kennard, 1900; Hinton, 1901). According to Sutcliffe and Kowalski (1976), this pit was c. 650 m to the west of the GCR site. It was certainly within the same terrace remnant
Elsewhere the Grays and Little Thurrock brickearth has yielded vertebrate remains, molluscs, ostracods, plant remains, pollen and, less frequently, Palaeolithic artefacts (Hinton and Kennard, 1900; Wymer, 1968, 1985b; West, 1969; Hollin, 1977). The principal source of palaeoliths has been Globe Pit, situated at the extreme eastern end of the brickearth spread, where a rich Clactonian industry has been recognized (King and Oakley, 1936; Wymer, 1957). The artefacts occur principally in gravels underlying the brickearth, but have also been reworked into the latter deposit (Wymer, 1957, 1968, 1985b; Snelling, 1964). The artefact-bearing gravel is believed to be part of the Lynch Hill/Corbets Tey Formation, of mid-Saalian age (Bridg,land, 1988a; see above, Introduction and Purfleet). The recovery of a large Clactonian assemblage from the mid-Saalian Corbets Tey Gravel is somewhat problematic, as this industry has normally been associated with late Anglian or Hoxnian sediments, such as the Lower Gravel at Swanscombe and the Clacton Channel Deposits (Wymer, 1974; see above, Swanscombe; Chapter 5, Clacton). This has led to suggestions that the deposits at Little Thurrock are older than their position within the terrace sequence suggests (King and Oakley, 1936; Wymer, 1968).
The surviving Pleistocene sediments in Globe Pit are concentrated in two areas. At the northern edge of the site, in a small area occupied by allotments, a deposit mapped as Boyn Hill Gravel overlies Thanet Sand at 20.5 m O.D. (see
The earliest detailed description of exposures in the Pleistocene deposits at Little Thurrock was by Morris (1836), who recorded laminated beds with comminuted shell debris amongst various sediments occupying a 'valley' between the higher ground to the north (formed by the Chalk of the Purfleet Anticline) and a much lower 'ridge' of Chalk to the south. The latter was clarified by Dewey et al. (1924), who noted that the channel filled with brickearth is separated on its southern side from the alluvium of the modern valley by a low gravel-covered ridge of Chalk. This gravel, which was described by Tylor (1869), may form part of the Taplow/ Mucking Formation (see Introduction to this chapter;
The first published illustration of a section in Globe Pit was by Hinton and Kennard (1900, p. 364). This showed gravel and brickearth of their 'Middle Terrace Series' overlying material that, in the caption to the illustration, they termed 'Gravel and Sand washed down from [the] valley to the north (High Terrace Series derived)'. This last bed, which formed the northern edge of the Pleistocene deposits in Hinton and Kennard's section, was probably the equivalent of the gravel at the GCR site. Descriptions of the site have been provided in recent years by Wymer (1957, 1968, 1985b), Snelling (1964), West (1969) and Hollin (1977). The most detailed section through the sequence, most of which is now quarried away, was illustrated by Wymer (1985b). This showed brickearth above a lower gravel resting on Chalk at 6 m O.D. and overlain by a later gravel
This interpretation, which was supported by West (1969) and Evans (1971), would appear to link back to the above quotation from Hinton and Kennard, who were presumably describing the same sloping gravel body.
Reappraisal of the site in 1983, as part of the Geological Conservation Review (Anon., 1984b), has raised serious doubts about this interpretation. Sections cut in the remaining deposits indicated that fluvially bedded sand and gravel, albeit with penecontemporaneous deformation structures, can be traced to below 10 m O.D.
Wherever the Thanet Sand surface was uncovered at Globe Pit in the 1983 excavations, it proved to be extremely uneven, with what appeared to be 'potholes' in the old river bed at the base of the gravel. However, in a larger area of Thanet Sand surface that was uncovered in 1984 (section 1;
2. Fossiliferous brickearth (now removed)
1. Lower Gravel, containing Clactonian artefacts (feather-edge survives).
This sequence is assigned here to the Lynch Hill/Corbets Tey Formation. The clast-lithological contents of the basal Corbets Tey Gravel at Globe Pit, as well as those of the Orsett Heath Gravel in the northern part of the workings (outside the GCR site), are recorded in
The principal scientific interest in the remaining sediments at Globe Pit, in addition to the important evidence they provide for the depositional history and stratigraphy of the Thames terrace system, arises from the Clactonian artefacts they contain. Considerable emphasis has been placed on the stratigraphical significance of this assemblage by past workers. King and Oakley (1936) regarded the occurrence at Little Thurrock of an uncontaminated Clactonian industry as evidence that the deposits there were older than the Lower Middle Gravel at Swanscombe, which is at the 'High Terrace' level. They concluded that the Little Thurrock sediments, although at a 'Middle Terrace' elevation, filled a channel excavated by the Thames during the interval between the deposition of the Swanscombe Lower Loam and Lower Middle Gravel, during which time the upper surface of the Lower Loam was subjected to subaerial weathering (see above, Swanscombe). The well-known channel deposits at Clacton, containing the type-Clactonian industry, were attributed to the same time interval,
their 'Clacton-on-Sea Stage'. This model, although rejected by Marston (in Bull, 1942), was supported by Oakley and Leakey (1937) and Warren (1955). It implied (1) that much of the 'High Terrace' (now recognized as Boyn Hill/ Orsett Heath Gravel), which contains Acheulian hand-axes, was younger than the 'Middle Terrace' deposits at Little Thurrock; (2) that aggradation had been continuous, following deposition of the Little Thurrock deposits, until reaching the highest level of the 'High Terrace', at c. 42 m O.D. at Dartford Heath; and (3) that the geomorphological 'Middle Terrace' feature had resulted from a combination of erosion and deposition, as the river subsequently incised its valley for a second time to the 'Middle Terrace' level. The Clactonian industry was, until recently, considered to appear earlier in Britain than the Acheulian (see Wymer, 1974), so its presence at Little Thurrock, uncontaminated by Acheulian material, provided an important basis for the above interpretation of the aggradational sequence.
Early records of archaeological material from Little Thurrock, although rarely containing details of location, probably refer to the Globe Pit or sites nearby. Spurrell (1892, p. 194) described 'numerous "waster" flint flakes' from the easternmost of the Grays pits, 'that at Little Thurrock', and Smith (1894, p. 271) illustrated a 'worked' red deer antler that, along with numerous other fragments of antlers, bones, tusks, and 'keen flakes and implements', he claimed to have found in situ on 'the Palaeolithic floor at Little Thurrock'.
The only record of a non-Clactonian artefact from the site is of a 'side scraper', probably of Acheulian affinities, reported to have been found in situ in the 'Middle Terrace' by Kennard (1904). He recognized that this differed from 'the true Middle Terrace implements' (1904, p. 112) and suggested that it had been reworked from the 'High Terrace' (Boyn Hill/Orsett Heath Gravel). Kennard (1916) later referred to 'gravel overlying the brickearth at the Globe Pit', which he claimed to have yielded a number of implements, including the one he had himself described in 1904. This presumably refers to the upper gravel figured by Wymer (1985b;
King and Oakley's (1936) correlation of the Little Thurrock sediments, and the artefacts they contain, with those at Clacton was reaffirmed by Warren (1942, 1955), who further suggested (1947) that the incision event represented by the channels at Grays and Clacton also preceded the aggradation of his 'Furze Plan Stage' deposits in the Maidenhead area. This is an interesting suggestion, since both the Furze Platt deposits (see Chapter 3, Cannoncourt Farm Pit) and the artefact-bearing gravel at Globe Pit are now believed to be part of the Lynch Hill/ Corbets Tey Formation
Wymer (1957) pinpointed the source of Clactonian artefacts at Little Thurrock to a small remnant of gravel overlying a 'bench' at 49 ft (15 m O.D.) in the north-eastern corner of Globe Pit (approximately coinciding with the GCR site). He collected 289 flakes and five 'chopper-cores' from this gravel. Many of the former show secondary working and over half are in mint or fairly sharp condition, indicating minimal transport prior to incorporation in the gravel (Wymer, 1957, 1968). No Acheulian implements or finishing flakes were encountered, leading Wymer to conclude that the collection represents a single industry, with no admixture of material from any other. Wymer's sections were reopened and extended in 1961 by Snelling (1964), when some 280 worked flints were obtained, including two hammerstones, two waste cores and very occasional core-tools similar to those described by Wymer.
Hart (1960), who also described the deposits at Globe Pit, recorded a sequence of brickearth with gravelly partings, with Clactonian artefacts occurring in the latter. In an undated, unpublished report on file with English Nature, Hart recorded gravel containing Clactonian artefacts and mammalian remains occupying a channel with a base level of 6.5 m O.D., well below the level of the 'bench' described by Wymer (1957). The former existence at this level of deposits yielding (mainly sharp) Clactonian material has been confirmed recently by Wymer (1985b;
Even before the discovery of a Clactonian industry at Little Thurrock, a number of authors had concluded from its mammalian fauna that the Grays brickearth was of a greater age than had usually been attributed to deposits of the 'Middle Terrace' (Hinton, 1910, 1926a, 1926b; Kennard, 1916; Warren, 1923a). Hinton (1910, 1926a, 1926b) placed considerable emphasis on evidence from small mammals in support of this conclusion. This view was perpetuated in the stratigraphical model of the Lower Thames terraces proposed by King and Oakley (1936), who correlated the Little Thurrock deposits with the hiatus between the Lower Loam and Lower Middle Gravel at Swanscombe (see above). Since the Swanscombe sequence has been almost universally ascribed to the Hoxnian Stage (Sutcliffe, 1964; Kerney, 1971), a Hoxnian age for the Little Thurrock deposits is implied by this interpretation. Kerney (1959b) also considered a Hoxnian age to be likely on the basis of similarities between the molluscan fauna at Grays and that in the Swanscombe Middle Gravels. Many elements of the characteristic assemblage from the Middle Gravels at Swanscombe (see above) also occur in the Grays collections; an example is the woodland snail Macrogastra ventricosa (Draparnaud), which is restricted, within the Thames system, to these two localities.
The western tract of brickearth in the Grays district was considered by some early workers to be of a later age than that at Little Thurrock, as it yielded different mammalian species (particularly voles) and was associated, at West Thurrock, with a Levallois industry (Kennard, 1916; Warren, 1923a, 1923b; see below, Lion Pit). Both sets of deposits have, however, been attributed in recent years to the Ipswichian Stage, principally on the basis of palynology (West, 1969; Hollin, 1977; Gibbard et al., 1988). West (1969) obtained pollen from the brickearth at Globe Pit (now destroyed), which was banked against the gravel that yields Clactonian artefacts
The rich mammalian fauna from the Grays and Little Thurrock brickearth, although much celebrated by early collectors (lists were supplied by Whitaker (1889), Hinton and Kennard (1900) and Hinton (1926b)), has failed to provide clear biostratigraphical evidence for the age of the deposits. It has therefore been possible to reconcile the assemblage with attributions to both the Hoxnian and Ipswichian Stages. The view that this eastern spread of brickearth is older than that to the west of Grays (Kennard, 1916; see below, Lion Pit) has, however, persisted (see Wymer, 1985b). The record of hippopotamus from Little Thurrock is of considerable significance, as it would seem to indicate correlation with the Ipswichian Stage (sensu Trafalgar Square); however, the record of horse from the same deposit appears to be contradictory, since that animal is believed to have been absent during the Ipswichian — as was the bivalve Corbicula fluminalis, also present at Little Thurrock (Chapter 1; Chapter 2, Stanton Harcourt and Magdalen Grove). Wymer (1985b) noted that there are many difficulties in assessing the early faunal collections from the Grays district, as the precise provenance of many specimens is unknown. He was therefore inclined to dismiss the record of hippopotamus from the Little Thurrock brickearth. There is considerable justification for this revision: Abbott (1890) had recorded hippopotamus remains from West Thurrock (although this record must also be regarded as doubtful — see below, Lion Pit) and Hinton and Kennard's (1900) faunal assemblage for the Grays deposits, the basis of most later lists, was an amalgamation of records from West Thurrock and Grays and Little Thurrock. Only later did these authors realize that the brickearths to the west and east of Grays were of different ages (Kennard, 1916; above). In fact, hippopotamus appears in faunal lists from most fossiliferous sites in the Lower Thames, including Swanscombe, where the record was based on a single fragment (subsequently discredited by the analysis of its fluorine content (Oakley and Gardiner, 1964; Sutcliffe, 1964)). Thus Hinton (1926a, p. 339), referring to two of the rare exceptions, was able to state that 'Hippopotamus …, so characteristic of the earlier Thames horizons, [has] not been found at Crayford or Erith'. The opposite view would now be taken; hippopotamus is currently regarded as present only in the latest of the Thames interglacial deposits (Chapter 1).
Hollin (1971, 1977), who obtained further supplementary pollen samples from Globe Pit and elsewhere in the Grays brickearth (sensu lato), considered their high pine and low birch frequencies to support West's correlation of the deposits with the Ipswichian Stage. He interpreted the brickearth as a tidal deposit and suggested that, as at Purfleet (see above), it recorded estuarine aggradation to 14 m O.D. in response to a rise in sea level brought about by an Antarctic ice surge during the Ipswichian. The interpretation of this and other sites as representing the infilling of the Lower Thames valley during an Ipswichian sea level rise has recently been supported by Gibbard et al(1988).
The correlation of the Grays and Little Thurrock sediments with the Ipswichian Stage is not supported by amino acid ratios from shells from the early collections (Miller et al., 1979; Bowen et al., 1989). Both sets of authors obtained D : L ratios of around 0.29 (using the genera Corbicula and Bithynia) and both grouped the site with Swanscombe, which, according to the interpretation of Bowen et al. would imply correlation with Oxygen Isotope Stage 11 (see above, Swanscombe; Chapter 1).
Bridgland (1983a) considered the Little Thurrock sequence to fall within his Barvills Gravel, which was later reclassified as Corbetts Tey Gravel (Bridgland, 1988a; Gibbard et al., 1988). This formation was correlated by Bridgland (1988a) with the Rochford Gravel of the Southend area, implying correlation of the basal gravel and interglacial sediments (brickearth) at Little Thurrock with the Rochford Channel Gravel and Rochford Channel interglacial deposits respectively. This correlation has recently been retracted, the Corbets Tey Gravel now being regarded as equivalent to the Barling Gravel of the Southend area (Bridgland et al., 1993; see Chapter 5, Part 2). The channel at Grays, recognized by early workers such as Morris (1836), Tylor (1869) and Dewey et al. (1924), is thus regarded as an upstream equivalent of the Shoeburyness Channel. Since the Corbets Tey Gravel is correlated with the mid-Saalian Lynch Hill Formation of the Middle Thames (Bridgland, 1988a), this interpretation provides a stratigraphical argument for an intra-Saalian age for the Grays interglacial
The above correlations provide the basis for part of the revised stratigraphical scheme for the Thames terrace sequence presented in Chapter 1. Besides the Shoeburyness Channel Deposits, which have been investigated in detail only very recently (H.M. Roe, pers. comm.), the Little Thurrock interglacial sediments are considered, according to this scheme, to correlate with temperate-climate deposits at Stoke Newington, Corbets Tey, Belhus Park and Purfleet, all of which have yielded comparable molluscan faunas with C. fluminalis (see above, Purfleet;
The Globe Pit GCR site, however, retains little if any evidence to bear on the age of the Grays interglacial. Its main importance, as stated above, stems from the Clactonian artefacts that occur in the gravel underlying the interglacial beds. This gravel (bed 1, above) is presumed to represent the pre-interglacial aggradational phase (phase 2) of the Lynch Hill/Corbets Tey Formation, according to the climatic model for terrace formation presented in Chapter 1. The equivalence of the gravel underlying the brickearth and that from which Wymer (1957) and Snelling (1964) obtained Clactonian artefacts was demonstrated by the GCR excavations. The gravel that was observed above the brickearth (Kennard, 1916; Wymer, 1985b;
The interpretation outlined above clearly implies that the Clactonian artefact-bearing gravel (bed 1) at the GCR site post-dates the higher-level Orsett Heath Gravel, which contains hand-axes, thus refuting the stratigraphical significance of the former industry. Of probable relevance to this argument is the recovery of two possible hand-axe finishing flakes in abraded condition from the GCR excavations (Bridgland and Harding, in press), which appears to confirm that the Little Thurrock gravel postdates hand-axe manufacture in the area. However, the question remains as to whether the Clactonian industry at Globe Pit is contemporaneous with the Corbets Tey Gravel or whether it is derived from an older deposit, of similar age to the Swanscombe Phase I sediments. The balance of evidence suggests that the Globe Pit assemblage results from the accumulation, in the feather-edge of the Corbets Tey Gravel, of a vast amount of material from a nearby Clactonian working site. The Corbets Tey Formation would be expected to contain reworked Palaeolithic material from the higher Orsett Heath Gravel, which may be represented by the hand-axe finishing flakes. The relation between the age of the Clactonian working site and the age of the gravel cannot be determined. The archaeological material may have been preserved for a considerable time in an earlier deposit in the vicinity and then reworked into the Corbets Tey Gravel. The largely unabraded condition of the artefacts implies minimal transport by the Thames, which is in tune with their apparent concentration at the edge of the channel (whether they are contemporaneous or reworked).
Abraded Clactonian material has also been recognized within a mixed assemblage of artefacts from interglacial and post-interglacial deposits of the Corbets Tey Formation (phases 3 and 4) at Purfleet (Palmer, 1975; Wymer, 1985b; see above, Purfleet) and from the upstream correlative of this aggradation, the Lynch Hill Gravel of the Middle Thames (Wymer, 1988). Wymer (1988, p. 89) suggested that 'a Clactonian Industry of crude chopper-cores and flakes, without hand-axes, is present in the Lynch Hill Gravels, as several such artefacts came from this gravel at Deep Lane, Burnham'. There is mounting evidence, therefore, that the use of the Clactonian knapping technique persisted after deposition of the Swanscombe Phase I deposits. If fresh Clactonian material is restricted, in the Lynch Hill/Corbets Tey Formation, to the pre-interglacial (phase 2) deposits, the implication is that the industry persisted into the next oxygen isotope stage after that represented at Swanscombe, Oxygen Isotope Stage 10
This review of previous descriptions and interpretations of the Little Thurrock site reveals that, despite considerable attention from geologists and archaeologists, the age of the deposits and their position within the Lower Thames terrace succession remains controversial. The role of Palaeolithic archaeology as a potential source of stratigraphical and relative dating evidence is currently under review. The Globe Pit industry provided an important foundation for past stratigraphical reconstructions of the Lower Thames sequence. The deposits were held to be older than their position in the 'Middle Terrace' (Corbets Tey Gravel) suggests and were frequently attributed to the Hoxnian Stage. Other workers, influenced by the relatively low elevation of the site, favoured an Ipswichian age. Interpretations of the archaeological and palaeontological evidence from these deposits have been revised in recent years and it now appears that some, perhaps all, of the early views were erroneous.
In current attempts at correlation between the Thames sequence and the deep-sea (oxygen isotope) record (Chapter 1), evidence from Globe Pit continues to be of considerable importance. In particular, the site complements the palaeontological evidence from Purfleet, which is considered to be its broad correlative. The two provide a picture of Lower Thames development during the aggradation of the Lynch Hill/Corbets Tey Gravel Formation, which appears to have occurred between Oxygen Isotope Stages 10 and 8 (inclusive).
The remaining deposits at Globe Pit provide an important reserve of gravel rich in Lower Palaeolithic (early Stone Age) flint artefacts of Clactonian type (named after another GCR Thames site, at Clacton in Essex). These comprise flakes and 'cores' (pieces of flint from which flakes have been removed), rather than the crafted tools that appeared in more advanced industries. The occurrence of these primitive artefacts at this site has been the subject of considerable interest for many years. The gravel here represents the middle of three terraces recognized on the north side of the Lower Thames valley, which would normally suggest that it was intermediate in age between the higher (older) terrace and the lower terrace. However, the high terrace at Swanscombe yields numerous hand-axes, part of an industry that is traditionally regarded as advanced and later than that found at Globe Pit. This led many workers to devise complex explanations of how the deposits here, at Little Thurrock, could be older than their position in the terrace sequence would seem to suggest. Reconsideration of the Lower Thames terrace sequence and the fossiliferous sediments within it, as well as the archaeological evidence from the gravels in the Lower and Middle Thames, leads to the conclusion that the gravel and the Palaeolithic industry at Globe Pit are indeed younger than the entire Swanscombe sequence. It is suggested here that they date from early in the Saalian, at around 350,000 years BP.