Danielle C. Schreve

Differentiation of the British late Middle Pleistocene interglacials: the evidence from mammalian biostratigraphy

Abstract Acknowledgement of the climatic complexities of the marine oxygen isotope (δ18O) record has inspired fresh investigations into methods of identifying and separating interglacial deposits on land. Biostratigraphical analysis of fossil mammalian assemblages, particularly those from long fluvial sequences, has proved to be a uniquely valuable technique in the differentiation of the various temperate episodes of the late Middle Pleistocene in Britain, thereby enabling a sequence of diagnostic mammalian assemblage-zones to be established. The scheme has provided an important means of correlation between geographically-distant localities and between different types of depositional environment. Using mammalian biostratigraphical information, this paper explores the evidence for three post-Anglian interglacials prior to the Last (Ipswichian) Interglacial, correlated with Stages 11, 9 and 7 of the oxygen isotope record, and presents the case for the recognition of much smaller-scale environmental and climatic oscillations within these interglacials, possibly corresponding to marine isotopic substages.

Sedimentology, palaeontology and archaeology of late Middle Pleistocene River Thames terrace deposits at Purfleet, Essex, UK

Middle Pleistocene fluvial deposits of the Corbets Tey Formation at Purfleet, Essex, provide evidence of an un-named and previously poorly recognized interglacial, thought to corrrelate with Oxygen Isotope Stage (OIS) 9. Previous attributions of the sediments to the Ipswichian (Last Interglacial) Stage are refuted. New investigations have yielded rich molluscan, mammalian and ostracod assemblages that indicate fully temperate conditions and the distal influence of marine transgression. Pollen analyses suggest a previously unrecorded phase of interglacial vegetational development. Clast composition, geomorphological evidence and the occurrence of molluscs that favour large rivers all point to deposition by the Thames, rather than in a minor tributary, as suggested previously. Three separate Palaeolithic industries in stratigraphical superposition are recognized at Purfleet, these being Clactonian, Acheulean and Levallois. Purfleet is therefore a key locality in the understanding of the early human occupation and exploitation of southern Britain, as well as for the interpretation and correlation of the terrace sequence in the Thames Valley.

Mammalian evidence from Middle Pleistocene fluvial sequences for complex environmental change at the oxygen isotope substage level

Abstract Mammalian remains have proved to be a uniquely valuable tool in differentiating between the various temperate episodes of the late Middle Pleistocene in Britain. Long fluvial records, such as that of the River Thames, have provided a template against which the mammalian biostratigraphical evidence may be tested, thereby enable a sequence of diagnostic mammal biozonations to be established. The mammalian evidence also identifies much smaller-scale environmental and climatic oscillations within these interglacials, possibly corresponding to isotopic substages. This paper reviews in detail two sites in the Lower Thames valley, Swanscombe and Aveley, attributed to MIS 11 and MIS 7, respectively, and presents the mammalian evidence for climatic complexity and habitat succession within these interglacials.

Island Britain – Peninsula Britain: Palaeogeography, Colonisation, and the Lower Palaeolithic Settlement of the British Isles.

Britains geographical status has fluctuated between an island and a peninsula of Europe several times over the past 500 kya, as sea-levels rose and fell in response to global climate change. In this paper, we outline the currently available lithological and biological evidence for these fluctuations and use it to help construct an heuristic biogeographical framework of human colonisation, settlement, and abandonment, proposing mechanisms that are coupled with both regional palaeogeographical evolution and global climatic change. When used as a means of interpreting the archaeological record, the implications of this framework suggests not only that large-scale socio-culturally relevant patterns may indeed exist in the lithic record, but that these may possibly be understood as part of the ebb and flow of different regional populations, measured against the backdrop of changing climates and landscapes. It is suggested that the Clactonian and Acheulean may represent separate pulses of colonisation, possibly by different European populations, following abandonment during the height of glacial periods: the Clactonian reflecting an early recolonisation event during climatic amelioration, the Acheulean representing a second wave during the main interglacial. This phenomenon is recurrent, being observable during the first two post-Anglian inter glacials. Other patterns in the lithic record are argued to reflect specific endemic technological developments among insular hominid populations during periods of isolation from mainland Europe. These represent some of the few patterns in the British Acheulean that cannot be interpreted more parsimoniously in terms of raw materials.

Correlation of English and German Middle Pleistocene fluvial sequences based on mammalian biostratigraphy

In this paper interglacial mammalian assemblages from key Middle Pleistocene fluvial sites in Germany are compared to Mammal Assemblage-Zones (MAZs) recently established in the post-Anglian/Elsterian sequence of the Lower Thames, U.K. It is believed that four separate interglacials are represented by the Lower Thames MAZs, correlated with oxygen isotope stages (OIS) 11, 9, 7 and substage 5e (although the last of these is Late Pleistocene). Nowhere in Germany can a full sequence of these interglacials be identified from mammalian evidence in a single terrace staircase, as is the case in the Lower Thames, although further research on the Wipper terraces at Bilzingsleben may identify such a sequence. It is also possible that the sequence of overlapping fluvial channels in the lignite mine at Schoningen will eventually produce a comparable mammalian story. Excellent correspondence has been recognized between the mammalian assemblages at Steinheim an der Murr and Bilzingsleben II and the Swanscombe MAZ from the Thames. These three sites are attributed to the Hoxnian/Holsteinian interglacial and are thought to correlate with OIS 11. Close comparison can also be made between the mammalian sequence from the celebrated travertine locality at Weimar-Ehringsdorf and two separate MAZs from Aveley, in the Thames, attributed to separate substages of OIS 7. An equivalent to the Purfleet MAZ of the Thames, which is believed to correlate with OIS 9, has yet to be identified in Germany.

Biostratigraphical correlation between the late Quaternary sequence of the Thames and key fluvial localities in central Germany

The shared characteristics of limestone bedrock geology and resultant calcareous groundwater have allowed excellent preservation of mammalian and molluscan faunas within the terrace sequences of the Lower Thames and the rivers of the Muschelkalk region of Thuringia, central Germany. The mammalian and molluscan assemblages from the Lower Thames have underpinned the dating of one of the most important late Middle Pleistocene sequences in Britain and probably also Europe; one that is the repository of a highly significant Lower and Middle Palaeolithic archive. The most complete terrace records in Thuringia are those from the River Wipper, in the region of Bilzingsleben, and the Ilm, around Weimar. Both here and in the Lower Thames, interglacial deposits representing the four major post-Elsterian temperate-climate complexes (=oxygen isotope stages (OIS) 11, 9, 7 and 5 of the oceanic record) have been identified. In the Thames the interglacials are represented by fluvially deposited sediments, whereas in Thuringia they are frequently represented by travertines that formed around calcareous springs, often containing exquisitely preserved fossils. Evidence from Lower Thames interglacial deposits within four different terrace formations (Boyn Hill/Orsett Heath, Lynch Hill/Corbets Tey, Taplow/Mucking and Kempton Park/East Tilbury Marshes) is reviewed, in addition to which new evidence from a site at Hackney Downs, East London, is summarized. The deposits at the last-mentioned site are part of the Lynch Hill/Corbets Tey Formation and include interglacial sediments attributed to OIS 9. As well as the record of travertine complexes from each terrace level within the Bilzingsleben staircase, the celebrated travertine sequence at Weimar-Ehringsdorf, on Terrace 4 of the Ilm, is described. The biostratigraphical and palaeoenvironmental evidence from the Ehringsdorf travertines compares closely with that from interglacial deposits at Aveley, in the Mucking Formation of Lower Thames; both are attributed to OIS 7, with comparison possible at the oxygen isotope substage level.

Hovk 1 and the Middle and Upper Paleolithic of Armenia: a preliminary framework

The territory of present day Armenia is a geographic contact zone between the Near East and the northern Caucasus. Armenian Middle and Upper Paleolithic records are both few and patchy as a result of the historical paucity of systematic archaeological research in the country. Consequently, it is currently difficult to correlate the Armenian Middle and Upper Paleolithic records with those from other neighboring regions. We present new archaeological and chronometric data (luminescence, U-Th, and 14C) from our ongoing research at Hovk 1 Cave in northeast Armenia. We discuss in particular two activity phases in Hovk 1 Cave for which we have outline chronometric data: (1) an early Middle Paleolithic occupational phase, dated by optically stimulated luminescence (OSL) to 104+/-9.8 ka BP(OSL); and (2) a Paleolithic occupational phase characterized by microlithic flakes dated by AMS 14C to 39,109+/-1,324 calibrated years BP(Hulu). The two phases are separated by a hiatus in hominin occupation corresponding to MIS 4 and an episode in early MIS 3. These chronometric data, taken together with the preliminary paleoenvironmental reconstruction of the Hovk 1 Cave and environment, suggest that these activity phases represent short-lived and seasonal use of the cave presumably by small groups of hunters during episodes of mild climate. Neither tool manufacture nor butchery appears to have taken place within the cave, and consequently, the archaeological record included, for the most part, finished tools and blanks. We address the chronology and techno-typological aspects of Hovk 1 lithics in relation to: (1) the Paleolithic records of Armenia, and (2) the broader interregional context of early Middle Paleolithic hominin occupation and the Middle-Upper Paleolithic transition in the Caucasus.

The obliquity-controlled early Pleistocene terrace sequence of the Gediz River, western Turkey: a revised correlation and chronology

The buried Early Pleistocene river terrace record of the Gediz River, around Kula, western Turkey has previously been considered to span the time interval equivalent to Marine Isotope Stages (MIS) 58–37 (c. 1.6–1.2 Ma), with the frequency of terrace formation mirroring obliquity-driven climate change. Whereas progressive Pleistocene incision of the Gediz River is seen as a response to regional uplift, the timing of fluvial incision, leading to terrace formation and subsequent new floodplain development, is believed to be climate-controlled with incision–deposition cycles resulting from varying sediment–discharge conditions, a direct consequence of changing climate and related vegetation change. New outcrop observations downstream of the original field area, alongside recently published geochronological data and improved understanding of the volcanic sequence, all now suggest that the previously published interpretation is incorrect. Here we present a revised stratigraphy based upon terrace gradients of c. 0.004–0.005 (previously 0.001), in which 11 terraces are identified but only terraces GT11 (the oldest) to GT6 (pre-lava incursion) predate volcanism. The available geochronology suggests that terraces GT6 (post-first lava incursion) to GT1 relate to the time interval MIS38–28 (c. 1.26–1 Ma). However, despite penecontemporaneous volcanism terrace formation continues to reflect sediment–discharge changes predominantly controlled by regional climate change.

Key Middle Pleistocene localities of the Lower Thames: site conservation issues, recent research and report of a Geologists' Association excursion, 8 July, 2000

A review of published data spanning two centuries, combined with new investigations at a number of critical sites, has confirmed the Lower Thames terrace staircase to be one of the most complete and best dated archives of late Middle Pleistocene environmental change in Europe. This recognition comes at a time when access to exposures of the key sediments has diminished to just a handful of conservation sites, mainly Sites of Special Scientific Interest (SSSIs), under increasing pressure from development. Four such sites, central to the recognition of the oxygen isotope stage (OIS) 9 and OIS 7 interglacials within the Lower Thames sequence, were visited by a GA excursion in July 2000. This paper combines a report of the excursion with discussion of the importance of the sites as well as conservation management issues.

Critical issues in European Quaternary Biostratigraphy

Abstract The papers presented here form the Special Issue of Quaternary Science Reviews on European Quaternary Biostratigraphy. New and testable frameworks for the subdivision of Pleistocene time are proposed, based upon the evidence from three fossil groups that have a long history of biostratigraphical application in Europe, namely pollen, molluscs and mammals. In addition, the potential biostratigraphical value of beetles, chironomids, ostracods and testate amoebae is explored. The diverse lines of fossil evidence are consistent with a more complex chronology than previously envisaged for the Pleistocene and underline the need for future multiproxy studies, underpinned by a sound lithostratigraphy and consistent numerical dating.