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The Red Crag Formation of eastern Suffolk was deposited in structurally controlled basins during the Pre-Ludhamian, Ludhamian and Thurnian stages. A regression during the Thurnian was followed by a transgression during the Antian/Bramertonian Stage, with the Norwich Crag Formation resting unconformably on strata as old as Upper Cretaceous. A regression during the Baventian Stage led to the formation of a complex of shoreface gravels (Westleton Beds) and intertidal clays at the mouth of a river which flowed from the English Midlands to reach the sea in the Southwold area. The Chillesford Clay Member was formed penecontemporaneously at the estuary of the proto-Thames, further south. A further marine transgression occurred during the Pastonian. The Pre-Ludhamian, Antian/Bramertonian and Pastonian transgressions are tentatively correlated with the reflectors respectively at the base of the Westkapelle Ground, Smith's Knoll and Winterton Shoal formations of the southern North Sea.

The distribution, lithology, palaeontology (pollen and spores, foraminifera molluscs and dinoflagellate cysts), heavy mineral content and palaeomagnetic properties of the Chillesford Clay Member of the Norwich Crag Formation are described, and compared with those of the Easton Bavents Clay that outcrops further north. The Chillesford Clay is a discrete unit forming the top of the marine Plio-Pleistocene sequence between Aldeburgh and Orford, Suffolk; it rests conformably on the Chillesford Sand Pollen spectra are dominated by non-arboreal pollen. Two local pollen assemblage biozones are recognized; the lower is similar to that of the Baventian, and the upper to that of the Pre-Pastonian a . A deterioration in climate from cool oceanic to cold is indicated. Foraminifera assemblages preserved in one sequence suggest a decline from temperate to cool conditions. Restricted mollusc assemblages found in one sequence may signify low temperatures. Dinoflagellate cyst floras differ from those of the Chillesford Sand and Easton Bavents Clay, and in all these deposits suggest warmer conditions than the other biological indicators, although their absence from part of the Chillesford Clay may indicate low temperatures. Heavy mineral suites from the Chillesford Clay, Easton Bavents Clay, Chillesford Sand and Red Crag Formation are similar and are more diverse than those of the overlying fluviatile Middle Pleistocene Kesgrave Formation; thus, the earlier concept of a distinctive mineralogy of the Easton Bavents Clay is refuted. Palaeomagnetic measurements were inconclusive. The Chillesford Clay is interpreted as a temporal correlative of the Easton Bavents Clay. Both deposits are thought to have been deposited in high intertidal conditions during the major marine regression that accompanied transition from the Bramertonian Stage (warm) to the Baventian cold Stage and Pre- Pastonian a cold Substage. This suggests that these two cold stages/substages are more closely related in time than previously thought, and that the relative stratigraphical positions of the Bramertonian and Baventian stages are the reverse of those originally envisaged. The Baventian to Pre-Pastonian a interval probably correlates with the Tiglian C4c Substage of the Netherlands sequence, and should be considered as part of a single cold stage, for which the Baventian has nomenclatural priority.

We review the fossil microtine rodent assemblages from the Lower Pleistocene deposits in eastern England, consisting mainly of marine sediments of the Norwich Crag and Cromer Forest-bed Formations. Material from 17 localities, including the ‘Weybourne Crag’ of the Norfolk Coast, the inland ‘Norwich Crag’, and the Crag of the north Suffolk coast has been studied. The taxa Mimomys pliocaenicus, M.rex, M.blanci, M.newtoni, M.pitymyoides, M .altenburgensis and Clethrionomys are recognized. Mimomys pitymyoides and M.altenburgensis are described for the first time from Britain. The type material of Mimomys reidi and M.newtoni is redescribed, and we show that M.newtoni Major 1902 is a senior synonym of M.hungaricus (Kormos), thus resolving confusion that has existed in the literature. The prior name for the species described by M. A. C. Hinton ( Monograph of the voles and lemmings (Microtnae) living and extinct . London: British Museum (Natural History) 1926) as Mimomys newtoni appears to be Mimomys blanci van der Meulen 1973. No evidence has been found for mixing of faunas of different age at a single horizon or locality. Differences in crown height are demonstrated between samples of Mimomys pliocaenicus from different localities, and differences between localities in the presence and absence of various species are tabulated. This evidence combined with current interpretations of the stratigraphy leads us to recognize three faunal groups. Group 1 faunas contain Mimomys pliocaenicus, M.reidi (type level), M.newtoni (type level), M.pitymyoides, M.blanci and Clethrionomys . They come from coastal deposits previously termed ‘Weybourne Crag’ and currently considered to date from Pre-Pastonian a to Pastonian. The faunas are clearly later than group 2 faunas, which contain Mimomys pliocaenicus, M.reidi, M.newtoni (these three species less advanced than in group 1 faunas), M.rex and M.altenburgensis (these two species lacking in group 1 faunas). Group 2 faunas come from inland ‘Norwich Crag’ localities and crags in Suffolk yielding a Chillesford type pollen assemblage, which are currently considered to date from the Bramertonian stage. Group 3 faunas contain Mimomys pliocaenicus, M.reidi and M.blanci and are from coastal deposits at Covehithe and Easton Bavents associated with Baventian stage clays. The evidence from the microtine rodents confirms the relative position of the Bramertonian and Pre-Pastonian a stages, but does not yet allow conclusions to be drawn on the relative age of group 3 faunas or the deposits in which they occur. The fauna of the Pastonian stage still requires clarification, since it is not possible to allocate unambiguously to this stage any of the material described here. The British Lower Pleistocene assemblages are broadly similar to material from Tegelen, The Netherlands (Tiglian TC4-6) and to material from superimposed loess levels at Stranzendorf, Austria. The British assemblages are characterized by the presence of Mimomys pliocaenicus and the absence of species with unrooted teeth, indicating that they belong to the Mimomys superzone of the biostratigraphic system of A. J. van der Meulen ( Quaternaria 17, 1-144, 1973) corresponding to the Villanyian stage. On the basis of microtine evidence we suggest limits to the correlation of the Pre-Pastonian and Bramertonian stages with the Netherlands chronostratigraphy. These limits are earlier than suggested by other lines of evidence. Correlation of the Pre-Pastonian with part of the Eburonian and the Bramertonian with part of the Tiglian is thought to merit consideration.

Etude palynologique sur sept excavations de la compagnie des eaux dans le suffolk. Presentation de la stratigraphie, interpretation des dates et place du «Norwick Crag» dans les series

This study uses a variety of criteria to examine short-range correlation within the Crag deposits in order to assess the validity of longer-range correlations within the British Pleistocene stage system. To this end, six rotary cored boreholes spaced at 0.5-1.0 km intervals were drilled along a north-south-aligned traverse between Aldeburgh and Sizewell, Suffolk. These show that the thick Red/Norwich Crag sequence is confined to a deep, sharply bounded basin, which is of probable erosional rather than tectonic origin. The undisturbed borehole core material enabled an assessment of the limits of stratigraphic resolution within these dominantly high-energy, shallow marine sediments to be made. Subdivision of the sequence was done on the basis of lithostratigraphical and biostratigraphical (foraminifera, pollen and spores, dinoflagellate cysts, and molluscs) criteria; chronostratigraphical methods (palaeomagnetism and amino acid chronology) were also applied. The various subdivisions indicated by each of these disciplines were in large part consistent, demonstrating that valid stratigraphic units had been identified. Only amino acid chronology did not indicate any obvious subdivision of the sequence. Three lithostratigraphical units were recognized within the thick Crag sequence. The lowest unit (AS-Lith 1) consists of coarse shelly sands interbedded with thinly laminated muds and fine sands. The middle unit (AS-Lith 2) consists of fine- to coarse-grained shelly sands arranged in two coarsening-upwards cycles. Units AS-Lith 1 and AS-Lith 2 are correlated on a lithostratigraphical basis with the Red Crag Formation of the adjacent Aldeburgh-Orford area to the south and are named the Sizewell Member and the Thorpeness Member respectively. The uppermost unit (AS-Lith 3) comprises fine- to medium-grained, well-sorted sands; it correlates with the Chillesford Sand Member of the Norwich Crag Formation of the adjacent Aldeburgh-Orford area. The Sizewell Member of the Red Crag Formation is normally magnetized and palaeontologically distinctive. The pollen, foraminifera and dinoflagellate assemblages firmly establish it as Pre-Ludhamian in age, and probably equivalent to an interval within the Reuverian C to Praetiglian Stages of the Netherlands. The Thorpeness Member of the Red Crag Formation is less easy to place within the British Pleistocene stage system. It is reverse magnetized, at least in part, and foraminifera assemblages suggest possible correlation with the Ludhamian Stage. No identifiable pollen or dinoflagellate assemblages were obtained. The Chillesford Sand Member of the Norwich Crag Formation is largely unfossiliferous but the borehole material has yielded a single pollen spectrum that suggests correlation with the Bramertonian Stage.

Recent investigations indicate that three distinct lithostratigraphical units can be recognized in the Red and Norwich Crag deposits of the area around Aldeburgh and Orford, Suffolk. These effectively represent a refinement of a stratigraphy originally suggested by Prestwich in 1871. A lowermost coarse-grained shelly sand, the Red Crag Formation, rests on an eroded London Clay surface and is banked against the Pliocene Coralline Crag. The Red Crag Formation passes upwards into a fine-grained generally unfossiliferous well-sorted sand, the Chillesford Sand Member, which overlaps the Red Crag Formation to rest directly on the Coralline Crag. The Chillesford Clay Member is regarded as the lateral equivalent of the upper Chillesford Sand Member, the two members together comprising the Norwich Crag Formation in this area. Sections that have been zoned palaeontologically may be integrated into this lithostratigraphical framework. These indicate that the Red Crag Formation correlates with the Pre-Ludhamian Stage, and the Chillesford Sand Member and the Chillesford Clay Member correlate with the Bramertonian Stage. Type sections are established for the three units described.