Sea‐level changes,river activity,soil development and glaciation around the western margins of the southern North Sea Basin during the Early and early Middle Pleistocene: evidence from Pakefield,Suffolk, UK

This paper outlines evidence from Pakefield (northern Suffolk), eastern England, for sea‐level changes, river activity, soil development and glaciation during the late Early and early Middle Pleistocene (MIS 20–12) within the western margins of the southern North Sea Basin. During this time period, the area consisted of a low‐lying coastal plain and a shallow offshore shelf. The area was drained by major river systems including the Thames and Bytham. Changes in sea‐level caused several major transgressive–regressive cycles across this low‐relief region, and these changes are identified by the stratigraphic relationship between shallow marine (Wroxham Crag Formation), fluvial (Cromer Forest‐bed and Bytham formations) and glacial (Happisburgh and Lowestoft formations) sediments. Two separate glaciations are recognised—the Happisburgh (MIS 16) and Anglian (MIS 12) glaciations, and these are separated by a high sea level represented by a new member of the Wroxham Crag Formation, and several phases of river aggradation and incision. The principal driving mechanism behind sea‐level changes and river terrace development within the region during this time period is solar insolation operating over 100‐kyr eccentricity cycles. This effect is achieved by the impact of cold climate processes upon coastal, river and glacial systems and these climatically forced processes obscure the neotectonic drivers that operated over this period of time. © British Geological Survey/Natural Environment Research Council copyright 2005. Reproduced with the permission of BGS/NERC. Published by John Wiley & Sons, Ltd.     

The British Pleistocene fluvial archive: East Midlands drainage evolution and human occupation in the context of the British and NW European record

This paper reviews the Pleistocene evolution and human occupation of the River Trent, the major fluvial artery draining Midland Britain, and places it within a modern Quaternary context. In contrast to the sedimentary records of the River Thames and the erstwhile Bytham system, which extend back to the early Pleistocene, present knowledge of the terrace sequence of the Trent, its tributary systems and associated ancestral courses extends back only to the Anglian glaciation (Marine Isotope Stage (MIS) 12), although the regional pre-Anglian drainage configuration is demonstrably complex. The post-Anglian sequence is well developed, with major terrace sand and gravel aggradations associated with each subsequent cold stage. Temperate-climate sediments correlating with MIS 7 and 5e have been recorded, although deposits relating to earlier interglacials during MIS 11 and 9 have yet to be identified. Evidence for human occupation in the form of Lower and Middle Palaeolithic artefacts has been recorded from terrace sediments correlated with MIS 8 and MIS 4, but the majority of this material is heavily rolled and abraded, suggesting significant reworking from older deposits. This review demonstrates that there is a rich palaeo-environmental record from the Trent but the lack of a high-resolution chronostratgraphic framework raises issues about correlation with other systems.     

Biostratigraphic and aminostratigraphic constraints on the age of the Middle Pleistocene glacial succession in north Norfolk,UK

Considerable debate surrounds the age of the Middle Pleistocene glacial succession in East Anglia following some recent stratigraphical reinterpretations. Resolution of the stratigraphy here is important since it not only concerns the glacial history of the region but also has a bearing on our understanding of the earliest human occupation of north‐western Europe. The orthodox consensus that all the tills were emplaced during the Anglian (Marine Isotope Stage (MIS) 12) has recently been challenged by a view assigning each major till to a different glacial stage, before, during and after MIS 12. Between Trimingham and Sidestrand on the north Norfolk coast, datable organic sediments occur immediately below and above the glacial succession. The oldest glacial deposit (Happisburgh Till) directly overlies the ‘Sidestrand Unio‐bed’, here defined as the Sidestrand Hall Member of the Cromer Forest‐bed Formation. Dating of these sediments therefore has a bearing on the maximum age of the glacial sequence. This paper reviews the palaeobotany and describes the faunal assemblages recovered from the Sidestrand Unio‐bed, which accumulated in a fluvial environment in a fully temperate climate with regional deciduous woodland. There are indications from the ostracods for weakly brackish conditions. Significant differences are apparent between the Sidestrand assemblages and those from West Runton, the type site of the Cromerian Stage. These differences do not result from contrasting facies or taphonomy but reflect warmer palaeotemperatures at Sidestrand and a much younger age. This conclusion is suggested by the higher proportion of thermophiles at Sidestrand and the occurrence of a water vole with unrooted molars (Arvicola) rather than its ancestor Mimomys savini with rooted molars. Amino acid racemisation data also indicate that Sidestrand is significantly younger than West Runton. These data further highlight the stratigraphical complexity of the ‘Cromerian Complex’ and support the conventional view that the Happisburgh Till was emplaced during the Anglian rather than the recently advanced view that it dates from MIS 16. Moreover, new evidence from the Trimingham lake bed (Sidestrand Cliff Formation) above the youngest glacial outwash sediments (Briton's Lane Formation) indicates that they also accumulated during a Middle Pleistocene interglacial – probably MIS 11. All of this evidence is consistent with a short chronology placing the glacial deposits within MIS 12, rather than invoking multiple episodes of glaciation envisaged in the ‘new glacial stratigraphy’ during MIS 16, 12, 10 and 6. Copyright © 2009 John Wiley & Sons, Ltd.     

Quaternary vertical crustal motion and drainage evolution in East Anglia and adjoining parts of southern England: chronology of the Ingham River terrace deposits

Prior to its disruption during the Anglian glaciation (MIS 12), the Ingham or Bytham River used to flow eastwards across central England and East Anglia into the southern North Sea. It thus had a much larger catchment than any extant river system in Britain; its headwaters may well have been as far away as North Wales and/or NW England. Terrace deposits of this former river system crop out across East Anglia and, as for any other river, can be used to investigate uplift, landscape evolution and the physical properties of the underlying continental crust. However, such an investigation has hitherto been hampered by inconsistencies between different authors' terrace schemes; furthermore, and controversially, one such scheme has formed the basis for the inference that the region was affected by a pre‐Anglian (MIS 16) glaciation. By re‐examining the raw data, the Ingham River deposits are shown to be disposed in three terraces, inferred to date from MIS 16, 14 and 12. The evidence previously attributed to pre‐Anglian glaciation is associated with the youngest of these terraces, and thus marks the MIS 12 (i.e. Anglian) glaciation; the argument for glaciation of the region in MIS 16 is thus an artefact of previous miscorrelation of the terrace deposits. It is inferred that development of the very large Ingham River was synchronous with decapitation of the former ‘Greater Thames’, or ‘High‐level Kesgrave Thames’ river, some time between MIS 18 and MIS 16. Uplift histories at representative localities across East Anglia have been modelled using composite data sets, combining the terrace deposits of the Ingham River and of the post‐Anglian rivers Lark and Waveney. The sites modelled are typefied by much faster uplift in the early Middle Pleistocene than in the late Middle Pleistocene; this effect is shown to be a consequence of the relative thinness (no more than ～7–8 km thick) of the mobile lower‐crustal layer, itself a consequence of the low surface heat flow in the London Platform crustal province. The post‐Early Pleistocene uplift tapers eastward, consistent with the observed downstream convergence of the Ingham and Waveney terraces, and is close to zero near the modern coastline around Lowestoft and Great Yarmouth. Stratigraphic relationships between the Ingham terrace deposits and temperate‐stage marine and terrestrial deposits in this coastal area allow sites to be dated; thus, Pakefield and Corton date from MIS 15, whereas Norton Subcourse dates from MIS 17. The oldest known Lower Palaeolithic sites in the region, characterized by flake artefacts, are Pakefield (MIS 15) and Hengrave (?MIS 14); younger pre‐Anglian sites that have yielded handaxes and/or fossil material of the water vole Arvicola cantiana date from MIS 13. The minimal vertical crustal motion in this coastal area, where temperate‐stage deposits from different climate cycles crop out close to present‐day sea level, does not imply high crustal stability; instead, it indicates a ‘hinge zone’ between the uplifting hinterland and the subsiding depocentre in the southern North Sea.     

The position and context of Middle Palaeolithic industries from the Ebbsfleet Valley,Kent, UK

The late Middle Pleistocene sites in the Ebbsfleet Valley, Kent, UK, have yielded archaeological assemblages critical to understanding the early Middle Palaeolithic of northwestern Europe. Despite a long history of research, the nature and context of these assemblages are still poorly understood. This paper clarifies the stratigraphic, environmental and archaeological records at Ebbsfleet. These reflect a cold–warm–cold sequence of climatic events, preserved within part of the Taplow/Mucking Formation of the Thames (Marine Isotope Stage (MIS) 8/7/6). Levallois artefacts are shown to be restricted to the lower part of the Ebbsfleet Channel sequence (Phases I and II) and are assigned to late MIS 8/early MIS 7. This material is associated with fauna indicative of open environments during both cool and temperate conditions. Handaxe assemblages are recorded from higher up the sequence (Phases III–V), but have been redeposited from higher terrace units nearby. No primary context archaeology is apparent during these later phases of aggradation. This may indicate that humans abandoned the site once available raw material became inaccessible, and may also reflect a decline in human presence in Britain during the latter part of MIS 7. Copyright © 2010 John Wiley & Sons, Ltd.     

The Middle Pleistocene terraces of the central Waveney valley,Earsham, south Norfolk,UK

Although substantial work has been done on the pre-glacial terraces of East Anglia, very little systematic work has been done to understand the origin of river terraces in East Anglia that have formed since ice last covered the region. This paper records the results of studies of exposures and borehole records in ‘classical’ Quaternary terrace landforms that are considered to have formed since the Anglian (MIS 12) Glaciation, in the middle Waveney Valley. These features have been examined in terms of their morphological and sedimentological properties, in order to provide a detailed record of their form and composition, understand their processes of formation, and identify their stratigraphical status. The results show that the main body of the highest terrace (Homersfield Terrace, Terrace 3) is not composed of river sediments, but of shallow marine sediments, and is a remnant of early Middle Pleistocene Wroxham Crag. River sediments, in the form of Anglian age (MIS 12) glaciofluvial Aldeby Sands and Gravels also exist in the area as a channel fill, cut through the Wroxham Crag, and reflect outwash erosion and sedimentation from a relatively proximal ice margin to the west. The results mean that the interpretations previously presented for the terrace landforms of the middle Waveney valley are not applicable. The issue of why the terrace stratigraphy, hitherto identified in East Anglia cannot be related to that for the River Thames to the south and the rivers of Midland England to the west, still requires further research.     

Tephrochronology,magnetostratigraphy and mammalian faunas of Middle and Early Pleistocene sediments at two sites on the Old Crow River,northern Yukon Territory,Canada

Alluvial and lacustrine sediments exposed beneath late Pleistocene glaciolacustrine silt and clay at two sites along the Old Crow River, northern Yukon Territory, are rich in fossils and contain tephra beds. Surprise Creek tephra (SZt) occurs in the lower part of the alluvial sequence at CRH47 and Little Timber tephra (LTt) is present near the base of the exposure at CRH94. Surprise Creek tephra has a glass fission-track age of 0.17 ± 0.07 Ma and Little Timber tephra is 1.37 ± 0.12 Ma. All sediments at CRH47 have a normal remanent magnetic polarity and those near LTt at CRH94 have a reversed polarity — in agreement with the geomagnetic time scale. Small mammal remains from sediments near LTt support an Early Pleistocene age but the chronology is not so clear at CRH47 because of the large error associated with the SZt age determination. Tephrochronological and paleomagnetic considerations point to an MIS 7 age for the interglacial beds just below SZt at CRH47 and at Chester Bluffs in east-central Alaska, but mammalian fossils recovered from sediments close to SZt suggest a late Irvingtonian age, therefore older than MIS 7. Further studies are needed to resolve this problem.     

The British Lower Palaeolithic of the early Middle Pleistocene

The archaeology of Britain during the early Middle Pleistocene (MIS 19–12) is represented by a number of key sites across eastern and southern England. These sites include Pakefield, Happisburgh 1, High Lodge, Warren Hill, Waverley Wood, Boxgrove, Kent's Cavern, and Westbury-sub-Mendip, alongside a ‘background scatter’ lithic record associated with the principal river systems (Bytham, pre-diversion Thames, and Solent) and raised beaches (Westbourne–Arundel). Hominin behaviour can be characterised in terms of: preferences for temperate or cool temperate climates and open/woodland mosaic habitats (indicated by mammalian fauna, mollusca, insects, and sediments); a biface-dominated material culture characterised by technological diversity, although with accompanying evidence for distinctive core and flake (Pakefield) and flake tool (High Lodge) assemblages; probable direct hunting-based subsistence strategies (with a focus upon large mammal fauna); and generally locally-focused spatial and landscape behaviours (principally indicated by raw material sources data), although with some evidence of dynamic, mobile and structured technological systems. The British data continues to support a ‘modified short chronology’ to the north of the Alps and the Pyrenees, with highly sporadic evidence for a hominin presence prior to 500–600 ka, although the ages of key assemblages are subject to ongoing debates regarding the chronology of the Bytham river terraces and the early Middle Pleistocene glaciations of East Anglia.     

Incised palaeo-channels of the late Middle Pleistocene Thames: age,origins and implications for fluvial palaeogeography and sea-level reconstruction in the southern North Sea basin

Multidisciplinary investigations of the infills of steeply-incised buried channels on the coast of Essex, England, provide important insights into late Middle Pleistocene climate and sea-level change and have a direct bearing on the differentiation of MIS 11 and MIS 9 in terrestrial records. New data are presented from Rochford and Burnham-on-Crouch where remnants of two substantial palaeo-channels filled with interglacial sediment can be directly related to the terrace stratigraphy of the Thames. The sediments in both channels accumulated in an estuarine environment early in an interglacial when mixed oak forest was becoming established. Lithological evidence suggests that the interglacial beds post-date the brackish-water infill of an older palaeo-channel ascribed to the Hoxnian and correlated with part of MIS 11, and pre-date terrace gravels (Barling Gravel) ascribed to MIS 8. An MIS 9 attribution is supported by molluscan biostratigraphy, palaeo-salinity and amino-acid racemization data. The relative sea-level record in this area thus includes evidence for two major marine transgressions during MIS 11 and MIS 9, with local maxima of >10 m O.D. Both are associated with sediments that show ‘Hoxnian’ palynological affinities. The wider significance of these findings, and of an intermediate phase of pronounced fluvial incision during MIS 10, is discussed.     

Evolution of the Thames estuary during MIS 9: insights from the Shoeburyness area, Essex

Multidisciplinary, litho-, bio- and amino-stratigraphical investigations of 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 Shoeburyness, where a deeply incised channel filled with interglacial sediment can be directly related to the terrace stratigraphy of the River Thames. Fossil assemblages confirm that the interglacial beds began accumulating in a freshwater environment, which became transformed into a dynamic estuary as relative sea-levels rose. Pollen data confirm that this occurred early in the interglacial when mixed oak forest was becoming established.The geological context of the sediments indicates that they post-date the Anglian glaciation, yet pre-date the Barling Gravel terrace aggradation, which has been ascribed to MIS 8. Amino acid racemisation data based on Bithynia opercula further constrain the age to the Hoxnian (=MIS 11) or to MIS 9. An MIS 9 attribution is favoured because (i) AAR data suggest that the sequence post-dates the interglacial channel-fill at Clacton, which is widely ascribed to the Hoxnian; (ii) the bivalve Corbicula occurred early within the interglacial (unlike its late appearance during the Hoxnian); and (iii) the sequence includes evidence for a marine transgression that occurred earlier in the interglacial cycle than it did at local Hoxnian sites.Plant macrofossil remains suggest that the early part of the Shoeburyness interglacial was associated with warmer-than-present summer temperatures. This is in keeping with inferences from sites at Barling, Cudmore Grove and Purfleet, which are also attributed to MIS 9. All three sites are similar in terms of their palaeo-vegetation and inferred relative sea-level histories and provide an emerging picture of this temperate episode in southern Britain.     

Early Devensian sediments and palaeovenvironmental evidence from the excavations at the Royal Oak Portal Paddington,West London,UK

This paper discusses the results of the investigation of Pleistocene sediments at the Royal Oak Portal (ROP) site on the new Crossrail scheme near Paddington Station, London. The site was sampled and recorded in May 2011 by archaeologists from Oxford Archaeology commissioned by Crossrail Ltd. The investigation revealed a sedimentary sequence associated with cool climate waterlain deposition towards the edge of the River Westbourne floodplain. During excavation an assemblage of around 100 identifiable large mammal bones was recovered, dating to the Late Pleistocene. The major concentration of bones, from bison and reindeer, was located and excavated from a shallow sequence of sediments. Analysis of the bones indicates that they represent a natural death assemblage, scavenged and subsequently disarticulated, transported by water, exposed and further dispersed and broken by trampling. The site is of regional and national importance because the assemblage derives from a well-constrained geological context, with associated dating evidence suggesting accumulation during the later parts of Marine Isotope Stage (MIS) 5 and continuing within MIS 4. The site is also of significance because it is one of a growing number of recently discovered sites away from the main fluvial archive for the British Middle and Upper Pleistocene. These sites have the potential to add significantly to our understanding of parts of the Pleistocene record that remain difficult to document through the investigation of the more active systems associated with major rivers such as the Thames, Severn or Trent.     

The Rautuvaara section,western Finnish Lapland,revisited – new age constraints indicate a complex Scandinavian Ice Sheet history in northern Fennoscandia during the Weichselian Stage

The Rautuvaara section in northern Finnish Lapland has been widely considered as the stratotype for the northern Fennoscandian late Middle and Late Pleistocene. It exposes four till units interbedded with sorted sediments resting on Precambrian bedrock. In order to shed light on the Scandinavian Ice Sheet (SIS) history and palaeoenvironmental evolution in northern Fennoscandia through time, a chronostratigraphical study was carried out at the Rautuvaara site. The succession was studied using sedimentological methods and different sand‐rich units between till units were dated using the Optical Stimulated Luminescence (OSL) method. The results obtained indicate that the whole sediment succession at Rautuvaara was deposited during the Weichselian Stage and there is no indication of older deposits. The SIS advanced across Finnish Lapland to adjacent areas to the east at least once during the Early Weichselian, twice during the Middle Weichselian (～MIS 4 and MIS 3) and once during the Late Weichselian substages. Glaciolacustrine sediments interbedded between the till units indicate that a glacial lake repeatedly existed after each deglacial phase. The results also suggest that there were two ice‐free intervals in northern Fennoscandia during the Middle Weichselian close to the SIS glaciation centre.     

An Anvilian (early pleistocene) marine fauna from western Seward Peninsula, Alaska

Cover sediments of the York Terrace exposed near the California River, western Seward Peninsula, Alaska, yield mollusks, ostracodes, and foraminifera that lived during the Anvilian transgression of early Pleistocene age. The fossiliferous sediments lie at the inner edge of the York Terrace, a deformed wave-cut platform that extends eastward from Bering Strait along much of the southern coast of Seward Peninsula. The seaward margin is truncated by the little-deformed Lost River Terrace, carved during the Pelukian (Sangamonian) transgression. The early Pleistocene sediments seem to have been deposited between the first and second of four glaciations for which evidence can be found in the California River area.The California River fauna includes several extinct species and several species now confined to areas as remote as the northwestern Pacific and north Atlantic. The fauna probably lived in water temperatures much like those of the present time but deeper water on the Bering Shelf is suggested.The presence of an early Pleistocene fauna at the inner edge of the York Terrace at California River shows that the terrace was largely carved before and during early Pleistocene time. However, a marine fauna apparently of middle Pleistocene age is found on the York Terrace near Cassiterite Peak, and this seems to indicate that the terrace remained low until middle Pleistocene time. Uplift of the York Terrace probably was accompanied by uplift of Bering Strait. The strait may have been deeper, and there may have been no land bridge between the Seward Peninsula of Alaksa and the Chukotka Peninsula of Siberia during most of early and middle Pleistocene time.     

Early and Middle Pleistocene landscapes of eastern England

This paper reviews the pattern of climate and environmental change in eastern England over the period of the Early and Middle Pleistocene, focussing especially upon northern East Anglia. Particular attention is given to the climate and tectonics that have brought about these changes and the distinctive geology, topography and biology that has developed. Throughout, an attempt is made to describe the new models that have been proposed for the Early and Middle Pleistocene of eastern England, and explain the reasons for these changes. The Early Pleistocene experienced relatively high insulation and relatively low magnitude climatic change and is represented primarily by non-climatically forced processes in the form of tidal current- and wave-activity which formed shallow marine deposits. It is possible to recognise a tectonic control in the distribution of deposits of this age because the surface processes do not have the power to remove this signature. The early Middle Pleistocene was dominated by higher magnitude climatic change involving, occasionally, climatic extremes that ranged from permafrost to mediterranean. The landscape at this time was dominated by the behaviour of major rivers (Thames, Bytham, Ancaster) and extensive coastal activity. In the latter part of the early Middle Pleistocene and the Late Middle Pleistocene the climate experienced major changes which resulted in periods of lowland glaciation and short intervals when the climate was warmer than the present. Details of tectonic activity are difficult to identify because they are removed by powerful surface processes, but it is possible to infer uplift focussed on the major interfluves of central England and subsidence in the North Seas basin. In the areas of glaciation the landscape changed radically from an organised terrain dominated by large rivers and extensive shallow coastal zones to complex, with small valleys, disrupted drainage and often discontinuous river, slope and coastal deposits. Likewise the switching off of the North Sea Delta and the opening of the Strait of Dover, separating Britain from continental Europe can be attributed to the onset of lowland glaciation. The case is made that eastern England was glaciated four times during the Middle Pleistocene: during MIS 16, 12, 10 and 6, and attention is given to recent evidence contradicting this model. Over the period of the Middle Pleistocene there is evidence for high biomass production occurring over short intervals coinciding with the climatic optima of MIS 19, 17, 15, 13, 11, and 7c, 7a and during most of these warmer periods, extending back to c. 750 ka (MIS 19/17), there is evidence in the region for the brief appearance of humans.     

黄河源区第四纪地质研究的新进展

通过对黄河源区的钻孔、自然露头的研究, 建立了黄河源区的第四纪地层层序。第四纪地层可划分为下更新统、中更新统、上更新统和全新统。下更新统为河湖相沉积; 中更新统主要有湖积物、冰碛物和冰水沉积物; 上更新统主要有湖积物、冰碛物、冰水沉积物、洪积物和河流沉积物; 全新统主要由河流沉积物、洪积物和湖积物构成。黄河源区的冰期可划分为3期, 即末次冰期、倒数第二次冰期、倒数第三次冰期, 末次冰期又可分为2个冰阶。黄河源区的湖泊演化可划分为早更新世、中更新世和晚更新世—全新世3个阶段: 早更新世的湖泊范围小; 中更新世的湖泊范围明显扩大, 在位置上也较早更新世的湖泊南移; 晚更新世的湖泊经历了两次的扩张—收缩变化, 到了全新世, 除现今还发育的几个湖泊外, 大多数地区的湖水已退出, 基本上转变为河流环境。在晚更新世末期到全新世初期, 封闭黄河源区的多石峡被切开, 湖水外泄, 现今的黄河形成了, 同时发生了袭夺长江水系的水流。     

Fluvial deposits within the Pleistocene Crag at Thorpe St Andrew,Norwich, England

This paper records the findings at a temporary exposure at Thorpe St Andrew near Norwich, Norfolk, UK in Early and early Middle Pleistocene Crag deposits. The British Geological Survey (BGS) describes the particular formation exposed as Norwich Crag consisting of Early Pleistocene shallow marine sediments. The section shows a succession of sorted sands and gravels overlain by a sandy diamicton. Based on field evidence and clast analysis, the sands and gravels are interpreted as the product of point bar and overbank sedimentation and represent the product of a river cutting into and aggrading within the more widespread shallow marine deposits. Composition of the sediments indicates derivation, primarily from Wroxham Crag Formation, with a contribution from Norwich Crag. The sandy diamicton is interpreted as late Middle Pleistocene Corton Till that is recorded in the area. A distinct pattern of colour changes at the top of the sands and gravels is interpreted as a soil that developed on the fluvial sediments before being overridden by the glacier that deposited the Corton Till. The existence of the fluvial sediments within the regional shallow marine deposits suggests that a fall of sea-level, possibly due to climate cooling, while the elevation of the sediments and the adjacent Crag implies that the site has been uplifted since sedimentation. This is the first observation of terrestrial sediments within the shallow marine Crag. The paper also makes a contribution to understanding the diagenetic processes that give deposits within this region some distinctive colour and sediment patterns.     

An Early Pleistocene hippopotamus from Westbury Cave,Somerset, England: support for a previously unrecognized temperate interval in the British Quaternary record

Although fossil assemblages from the late Early Pleistocene are very rare in Britain, the site of Westbury Cave in Somerset, England, has the potential to address this gap. The mammal fossils recovered previously from the Siliceous Member in Westbury Cave, though few in number, have hinted at an age for the deposits that is as yet unparalleled in Britain. Here, we describe the first bona fide occurrence of Hippopotamus in the British Early Pleistocene, discovered during recent reinvestigation of the Siliceous Member. The hippo fossil indicates a refined biochronological age of ca. 1.5–1.07 Ma for the Siliceous Member and a palaeoclimate that was warm and humid, which accords well with previous palaeoenvironmental inferences. A synthesis of late Early Pleistocene hippo occurrences suggests that the Siliceous Member hippo may have been part of an early colonization of north-west Europe by these megaherbivores, possibly during MIS (Marine Oxygen Isotope Stage) 31. Alternatively, it evidences a currently cryptic northward migration during an even earlier temperate phase. In either case, the Siliceous Member is likely to represent a warm period that has not been recognized previously in the British Quaternary record.     

Middle Pleistocene interglacial deposits at Barling,Essex, England: evidence for a longer chronology for the Thames terrace sequence

Results are presented from a multidisciplinary study of fossiliferous interglacial deposits on the northern side of the Thames estuary. These fill a channel cut into London Clay bedrock and overlain by the Barling Gravel, a Thames–Medway deposit equivalent to the Lynch Hill and Corbets Tey Gravels of the Middle and Lower Thames, respectively. The channel sediments yielded diverse molluscan and ostracod assemblages, both implying fully interglacial conditions and a slight brackish influence. Pollen analysis has shown that the deposits accumulated during the early part of an interglacial. Plant macrofossils, particularly the abundance of Trapa natans, reinforce the interglacial character of the palaeontological evidence. A beetle fauna, which includes four taxa unknown in Britain at present, has allowed quantification of palaeotemperature using the mutual climatic range method (T_max 17 to 26 °C; T_min ?11 to 13 °C). A few vertebrate remains have been recovered from the interglacial deposits, but a much larger fauna, as well as Palaeolithic artefacts, is known from the overlying Barling Gravel. The age of the interglacial deposits is inferential. The geological context suggests a late Middle Pleistocene interglacial, part of the post‐diversion Thames system and therefore clearly post‐Anglian. This conclusion is supported by amino acid ratios from the shells of freshwater molluscs. The correlation of the overlying Barling Gravel with the Lynch Hill/Corbets Tey aggradation of the Thames valley constrains the age of the Barling interglacial to marine oxygen isotope stages 11 or 9. The presence of Corbicula fluminalis and Pisidium clessini confirms a pre‐Ipswichian (marine oxygen isotope substage 5e) age and their occurrence in the early part of the interglacial cycle at Barling precludes correlation with marine oxygen isotope stage 11, as these taxa occur only later in that interglacial at sites such as Swanscombe and Clacton. Thus by process of elimination a marine oxygen isotope stage 9 age would appear probable. Copyright © 2001 John Wiley & Sons, Ltd.     

The Pleistocene terrace staircase of the River Thame, central-southern England, and its significance for regional stratigraphic correlation, drainage development, and vertical crustal motions

The Thame is one of the principal left-bank affluents of the Thames, the largest river in southern England; it joins the Upper Thames at Dorchester, ∼20 km downstream of Oxford. Its terraces include a younger group of four, which date from the late Middle Pleistocene and Late Pleistocene, are disposed subparallel to the modern river, and represent drainage within the modern catchment. At higher levels there are three older terraces, the Three Pigeons, Tiddington and Chilworth terraces, which are assigned to MIS 16, 14 and 12. With much gentler downstream gradients, these are fragmentary remnants of much more substantial fluvial deposits, indicating a much larger river that was disrupted by the Anglian (MIS 12) glaciation. This interpretation supersedes an earlier view that the glacigenic deposits in the Thame headwaters correlate with the Blackditch terrace, the highest of the younger group, which has hitherto provided an argument that the glaciation in this region occurred in MIS 10. It is suggested that the headwaters of the pre-Anglian ‘Greater Thame’ river were located near Northampton and that the Milton Sands of that area represent an upstream counterpart of the Chilworth terrace deposits. It is envisaged that this early Middle Pleistocene drainage geometry, located between the Jurassic limestone and Chalk escarpments, developed as a result of the increase in uplift rates that followed the Mid-Pleistocene Revolution (MPR). It is suggested that before this time, including during the Early Pleistocene, the modern Thame catchment and adjacent regions drained southeastward through the Chalk escarpment, but these small rivers lacked the erosional power to cut through the Chalk in pace with the faster uplift occurring in the early Middle Pleistocene, and so became diverted to the southwest, subparallel to the Chalk escarpment, to form the pre-Anglian ‘Greater Thame’ tributary of the Upper Thames. The post-MPR uplift is estimated to decrease northwestward from 90 m in the Middle Thames to 75 m near the Thame-Thames confluence and to 65 m upstream of Oxford. The post-Anglian (post-450 ka) component of uplift decreases northward from 33 m near the Thame-Thames confluence to an estimated ∼20 m in the Northampton area; the relative stability of the latter area makes feasible the proposed correlation between the Milton Sands and the pre-Anglian River Thame. Limited post-Anglian uplift in the Northampton area is also inferred from the upstream convergence of the terraces of the modern rivers Nene and Great Ouse. These observed lateral variations in vertical crustal motions reflect lateral variations in crustal properties (including heat flow, crustal thickness, and thickness of underplating at the base of the crust) that are known independently. This study thus provides, for the first time, an integrated explanation of the Pleistocene drainage development across a large region of central-southern England.     

River sections at the Byzovaya Palaeolithic site – keyholes into the late Quaternary of northern European Russia

Heggen, H. P., Svendsen, J. I. & Mangerud, J. 2009: River sections at the Byzovaya Palaeolithic site – keyholes into the late Quaternary of northern European Russia. Boreas, 10.1111/j.1502‐3885.2009.00109.x. ISSN 0300‐9483. The geological history of northern European Russia over the past two glacial cycles is reconstructed from the stratigraphy in river bluffs along the upper reaches of the Pechora River. From a till bed near the base of the sections it is inferred that the Barents–Kara Ice Sheet covered the area during the late Saalian (MIS 6). After deglaciation, and prior to the last interglacial, the area was flooded by an ice‐dammed lake, suggesting that the Pechora Basin was blocked by a subsequent ice advance at the very end of the Saalian. Ice‐wedge casts and periglacial sediments reflect a pronounced cooling with formation of permafrost during the Early Weichselian (MIS 5d). An overlying thick sequence of shallow lacustrine sediments accumulated in the ice‐dammed Lake Komi, formed by the advancing Barents–Kara Ice Sheet 80–100 kyr BP (MIS 5b?). Following drainage of the lake, many of the older formations were eroded by fluvial activity. Animal remains found together with palaeolithic artefacts within debrisflow sediments at the base of one of the incised gullies yielded radiocarbon ages around 28 000–30 000 ¹⁴C yr BP (33–34 cal. kyr BP). The surface with traces of human activities was subsequently covered by aeolian sediments representing the northern extension of the European belt of periglacial coversand that accumulated in the cold and dry climate during the late Weichselian (MIS 2). The results of this work confirm the assumption that the last shelf‐centred ice sheet that covered this part of Russia occurred during the late Saalian (MIS 6), but that this glaciation was followed by a younger and less extensive ice advance that has not been described before. There are no indications that local glaciers originating in the Ural Mountains reached the Pechora River valley throughout the last two glacial cycles.