1. The geo-chronological resolution of the archaeological resource and the relative importance of sedimentary, artefactual and palaeo-environmental data.

2. The spatial resolution of the archaeological resource, the relative importance of sedimentary and artefactual data, and the role of experimental archaeology and modern analogues.

3. The analytical frameworks associated with the secondary context archaeological research, and their applicability to extant research questions and the varying spatio-temporal scales of hominid behaviour.

4. The value of the secondary context archaeological resource, with specific reference to the range of available data and their spatio-temporal scales, their relevance to current research themes, and the current state of geoarchaeological methodologies.

1. Geochronological resolution of the archaeological resource
Existing models of fluvial activity suggest that the finest, currently available geochronological resolution is in the order of 10² and 10³ years in magnitude, with respect to individual fluvial sedimentary units and erosive events. Unfortunately, the chronological catchment of the derived archaeological materials occurring within these fluvial secondary contexts is much more variable, and encompasses a far wider potential time-span. It is clear that a number of factors influence the intensity of re-working and the magnitude of the potential chronological catchment, including the river zone, regional and local geological factors, and the final depositional position of the archaeology within the glacial/interglacial cycle.

A provisional framework for the application and interpretation of these factors is proposed here:

a. River zone: in those cases where a river is classified as an upland or piedmont system (following the definitions of Howard & Macklin (1999), with limited traces of terrace preservation and/or long-term sequences (based on field evidence and theoretical models where necessary), chronological catchments in the order of 10⁵ years are proposed. These estimates can be reduced where there is artefact typology provides a robust chronological marker, such as is the case with bout coupe handaxes (White & Jacobi 2002) and apparently with twisted ovates (White 1998a). However, it should be noted that there are relatively few examples of such chronologically-robust patterns in artefact typology. Finally, where the physical condition of secondary context specimens is suggestive of limited derivation and re-working, detailed field investigation of the sedimentary and depositional environment is recommended, prior to assumptions of a relatively brief chronological catchment.

b. Regional and local geological factors (bedrock controls): in cases of lowland or perimarine systems influenced by chalk bedrock controls (resulting in limited terrace preservation), chronological catchments in the order of 10⁵ years are again proposed. The above comments regarding the physical condition of the material and the presence of robust chronological marker artefacts are again applicable. It is also stressed that the extents of chalk-bedrock river systems should be assessed with respect to the potential downstream re-working of heavily re-worked artefacts over shorter and longer timespans. Of particular importance is the re-working of heavily derived artefacts from ‘gorge’-style chalk-bedrock river valleys into terrace-staircase, Tertiary bedrock systems, as has been argued for the assemblages from Dunbridge and Wood Green (e.g. Hosfield 2001).

c. Depositional position within the interglacial/glacial fluvial cycle: in cases of lowland and perimarine systems with well-preserved terrace sequences, chronological catchments ranging in order of magnitude from 10² to 10⁵ years are proposed. These vary on the basis of sub-cyclical variations in sedimentary and erosive activity, and the assignment of specific catchments to derived assemblages requires relatively detailed provenancing data with respect to the sedimentary sequence. There are currently no chronologically significant typological markers of sufficiently high-resolution to influence these assignments, although as previously, the physical condition of the artefacts and detailed sedimentary evidence should be employed as an independent test of the model.

2. Spatial resolution of the archaeological resource
There are relatively few extant models of artefact re-working and derivation (e.g. Harding et al. 1987; Hosfield 1999; Wymer 1999). These models have either focused upon experimental data (e.g. Harding et al. 1987) or have emphasised generic models of re-working without explicitly addressing the physical spatial component in the real world. The research presented here has suggested three approaches to identifying the spatial resolution associated with the secondary context archaeological resource, as represented by derived lithic assemblages deposited in fluvial sediments. All three of these approaches utilise the concept of a minimum spatial unit (MSU – see above). The first of these approaches adopts a limited view, defining the MSU as the spatial zone between the assemblage findspot and the head of the river system. This approach argues that physical artefact evidence and the geomorphological structure of the fluvial system cannot be employed to assess the internal structure of spatial palimpsest archaeology. The third approach adopts a geomorphological approach, stressing the role of fluvial features (e.g. river/tributary stream confluences) in creating sediment traps upon river floodplains. The MSU is therefore defined as the spatial zone between the assemblage findspot and the nearest preserved sediment trap upstream. This approach is interesting, and emphasises geoarchaeological processes and the sedimentary context of the archaeological resource. However, it requires further field testing prior to its adoption for the interpretation of archaeological assemblages. It also adopts a system-wide approach, and is therefore of limited usage for single-assemblage studies. The second approach emphasises the physical condition of the archaeological assemblage, stressing the état physique of individual artefacts. The MSU is variably defined in terms of distance categories, organised through orders of magnitude (10¹-10³), and based partially upon experimental laboratory work (Chambers in prep) and partially upon extant assemblage-studies (Broom and Dunbridge). The model suggests that relatively fine spatial resolution is currently detectable, based on the notion of artefacts derived from a series of increasingly distant source ideas. The spatial resolution markedly decreases with distance from the assemblage findspot, which reflects the difficulties of distinguishing transport modes over long-distance movement histories. The model also adopts fuzzy categories, reflecting the complexity of the real world processes of artefact derivation. This second approach is favoured here, primarily because it is based upon the artefact assemblage, which provides the most direct evidence of the transport histories associated with the archaeological resource.

However, it is also vital to integrate this physical data-based model of artefact derivation with the macro-scale processes of fluvial-system behaviour (e.g. intensive erosion and re-working in the upland zone). A provisional framework for the integration of these models and processes is therefore proposed here:

i. Artefact-based models: the proposed fuzzy categories (10^1-2, 10^2-2.5, 10^2.5-3, 10³⁺) provide a summary for the spatial re-working signature of secondary context assemblages (based on the proportion of artefacts falling into each category). The use of these categories supports the comparison of different assemblages, both from the same and different fluvial systems (although further experimental work is favoured, exploring abrasion patterns in different raw materials, the impact of suspended load transport, fine-grained sediment abrasion, and the development of abrasion during burial and partial-burial phases).

ii. River system models: this framework stresses the importance of highlighting apparent discrepancies between the re-working signature of assemblages and the generic models of river behaviour in different geomorphological zones or under different bedrock conditions. For example, an assemblage characterised by local derivation, occurring within an upland river zone, or a heavily derived assemblage occurring within a lowland zone. It is argued that under such conditions, further investigation of the artefact assemblage and the fluvial landscape is recommended. At the same time, it is noted that upland/lowland river contrasts in fluvial behaviour should not be over-stressed, given the marked variations in fluvial behaviour that occurred throughout river systems across the glacial/interglacial cycles of the Middle Pleistocene.

Overall therefore, the minimum spatial unit (MSU) defined here is spatially-variable, varying from the sub-hundred metres scale (10^1-2) to the km scale (10³⁺).

3. Analytical frameworks for the Secondary Context Archaeological Resourch
The geochronological and spatial resolutions proposed here for the secondary context archaeological resource cover a wide and variable spatio-temporal range. This variability provides a diverse set of spatio-temporal frameworks for the analysis of hominid and early human behaviour through the archaeological secondary contexts resource. A set of frameworks are proposed, with a generic description of the spatio-temporal scales and an outline of the potential analytical approaches to the problems of early human behavioural reconstruction. It is stressed that the frameworks are not exclusive, indeed in many cases informative behavioural analysis relies on the integration of the different, specified frameworks.

Overall therefore, these frameworks offer a range of spatial-temporal scales through which to explore a wide range of high and low-resolution patterns in lithic technology (e.g. manufacturing techniques), lithic typology, and artefact-based demographic signatures via a range of concepts including socio-cultural factors (e.g. imposed standardisation, the presence of homogeneity/heterogeneity in assemblages), ‘processual’ factors (e.g. raw material exploitation patterns, subsistence strategies and activities), landscape issues (e.g. river system evolution, raw material availability) and environmental (e.g. long-term fluctuations in magnitude and frequency of glacial-interglacial cycles, cold/warm climatic contrasts, habitat types). It is vital to stress that these frameworks are not independent. Indeed it should be apparent that the frameworks and their analytical approaches feed back into one another to provide a fuller understanding of the evidence. For example, population patterns associated with individual cold- and warm-climate events will support interpretation of demographic structure data at the glacial-interglacial level. Similarly, patterns in lithic typology and technology at the individual sedimentary unit level should inform interpretation of long-term patterns of technological ‘change’. Finally, it is stressed that these secondary context frameworks will both inform and be informed by, the evidence that is available from the primary context archaeological record. Although the primary and secondary context data sets ostensibly deal with separate data and issues, there is considerable interaction between the two contexts. For example, on-site evidence of a marginal, scavenging hominid would support a secondary context-based demographic model that revealed unstable, fluctuating populations.

4. The Value of the Secondary Context Archaeological Resource
The module has identified a range of spatio-temporal frameworks for the analysis of the secondary context archaeological resource. It also referenced a range of extant Palaeolithic research which has dealt with a number of the same questions (although not always employing secondary context archaeological data to do so). These research themes and questions are returned to here, with a view to the ability of secondary context data to contribute to the resolving of these issues. However, it is obviously important to stress at this point (following Hosfield 1999; Ashton & Lewis 2002), that the interpretation of patterns in secondary context (and sometimes in primary context data) must first consider and assess the potential collection biases associated with the material evidence.

i. Modelling of hominid demography (e.g. Hosfield 1999; Ashton & Lewis 2002).

ii. Identifying colonisation routes and occupation histories (White & Schreve 2000; Ashton & Lewis 2002).

iii. Spatio-temporal trends in artefact typology and technology (Mithen 1996; Wenban-Smith 1998; White 1998a, 2000; & Jacobi 2002).

iv. Alternative models of technological production, incorporating raw materials (e.g. White 1998b; Ashton et al. 1994; McNabb & Ashton 1992), situational contexts (e.g. Ashton et al. 1991), and cultural traditions (e.g. Mithen 1996; Wenban-Smith 1998).

Overall, it is clear that the secondary context archaeological resource dominates Britain’s early prehistoric archaeological record, in terms of the quantity of material, and the spatial-temporal coverage of the assemblages. In many cases, the resource is represented by collections of stone tools (e.g. handaxes), for which relatively little precise provenancing information is available. A key stage in the evaluation of these data is therefore the assessment of the scales of spatio-temporal resolution associated with the assemblages. Given the widespread absence of accurate field data, these assessments are primarily based on the artefacts themselves (with respect to their spatial derivation and re-working) and broad-scale geomorphological mapping of fluvial terrace systems.

The spatio-temporal models presented proposed a series of analytical scales, based on the relative degree of horizontal and vertical re-working to which the components of the secondary context archaeological assemblages had been subjected. These scales do not identify specific timescales or exact distances in space, reflecting the complexity of the processes being modelled. The analytical scales were based upon orders of magnitude, within which the resolution decreased in proportion to the degree of horizontal and/or vertical re-working. The key advantages of these frameworks is that they can be reconstructed on the basis of relatively limited contextual information. The spatial models utilised artefact data (the état physique) while the temporal models exploited generic river system behaviours (e.g. upland/lowland contrasts), current models terrace formation, and low-resolution provenance data (e.g. the recovery of artefacts from basal gravels).

The models of spatio-temporal resolution provided a matrix of analytical frameworks, across which different elements of hominid behaviour could be investigated. The frameworks stressed the time- and space-averaged nature of the data, but unlike the majority of existing approaches, exploited these characteristics to explore robust patterning. For example, three frameworks are presented for the exploration of demographic patterns, all at the basin-wide scale, but ranging from short-term traces (lasting a few hundred or a few thousands of years and potentially associated with uniform palaeo-environmental conditions) to long-term signatures, accumulating across single glacial-interglacial cycles. By contrast, the series of locale-orientated frameworks enable short- and long-term patterns of raw material exploitation and its impact upon tool-making to be explored. These approaches therefore provide a long-term perspective upon early prehistoric archaeology and behaviour that cannot be achieved from higher-resolution data.

These secondary context data are dominated by lithic evidence (predominantly core tools and large flakes – although the impact of selective collection histories must always be considered with respect to these data). There are also occurrences of biological data (predominantly large mammal fauna, although other material does occur), although this evidence is more localised, reflecting preservation factors (e.g. soil chemistry). These data have clear, application to the problems of site formation (which is fundamental to the interpretation of secondary context data), through the état physique of the lithic data, and the range of artefacts within the assemblages. By contrast, the use of these data for palaeo-environmental reconstructions is more problematic. In those instances where high-resolution palaeo-climatic indicators (e.g. beetle assemblages) occur within secondary context sequences (e.g. in localised fine-grained silt lenses within the gravels), it is not possible to relate it to the derived archaeology occurring throughout the sequence. The palaeo-climatic reconstructions based upon these data can provide an indication of possible habitat types that existed at some point during the deposition of the complete sedimentary sequence, but it is not possible to explicitly populate these habitats with either artefacts or hominids. With respect to lower-resolution palaeo-environmental data (e.g. large mammals) occurring within coarse-grained, gravel units, the same problem exists – namely that direct associations cannot be made between derived lithic materials and derived fauna. However, it should be noted that the two data sets operate at the same order of temporal magnitude, and therefore that provisional comparisons of these time-averaged data sets can be made. Unlike these palaeo-environmental questions, the secondary context resource has clear applications to a range of current behavioural questions in early prehistoric archaeology. Inevitably these applications tend towards research themes that operate at the lower-resolution analytical scales – reflecting the minimum chronological and spatial resolutions that are achievable for these data. Examples include demographic patterning and artefact-based analysis (raw material patterning, industry variability, diagnostic morphologies, and manufacturing processes and traditions). It is stressed that these data can be explored at a series of different spatial and temporal scales, and the interplay between these analytical frameworks provides a more comprehensive understanding of the processes at work:

i. For example, demographic models at the glacial/interglacial scale (10⁴ and 10⁵ years) reveal long-trends in hominid colonisation and population dynamics over the course of the Middle Pleistocene, but reveal little about the ebb and flow of populations over the course of a single warm/cold cycle. These gaps in understanding can be explored through demographic data at the sub-cycle level (e.g. derived artefacts from different sedimentary units in a single terrace sequence – following the Bridgland (1996) ‘sandwich’ model), which may document fluctuations in occupation histories and therefore reveal hominid habitat and climate preferences. Comparison of river system data may also reveal regional variations in occupation histories, potentially highlighting the importance of a range of factors including habitat preferences, raw material and other resource availabilities, and the role of different networks (e.g. the Thames/Rhine system) in hominid mobility and the ebb and flow of populations.

ii. With respect to artefact-based analysis, patterns in typology at the glacial/interglacial cycle level may reveal long-term trends in lithic technology (e.g. stability or change), while higher-resolution patterns may indicate shorter-term trends in lithic production, perhaps in response to palaeo-climatic factors. These trends can also be linked to behavioural models of tool-making, for example at Broom the homogeneity of the lithic record over a cold-warm-cold sedimentary cycle (currently proposed to represent MIS-8/7/6) is highly suggestive of a typologically diverse, but stable lithic technology. At the higher-resolution scale of the individual units within the sedimentary cycle, the repetitive diversity of the assemblages (see Module 4 for further details) appears to indicate an absence of imposed standardisation upon tool-making activities.

Overall, it is proposed here that the secondary context archaeological resource has a clear, unambiguous value with respect to the investigation of early prehistoric archaeology. It enables the identification of archaeological patterns and behavioural elements that operate at coarse-chronological and spatial levels, and which cannot be identified from on-site approaches. However, it also generates data which can be related back to high-resolution studies of hominid behaviour, while the varied spatio-temporal frameworks identified here provide a robust mechanism for the integration of on- and off-site archaeology in time and space.

The successful interrogation of this resource is therefore reliant upon:

i. Future field testing of geoarchaeological models of sediment and artefact re-working.

ii. Continued refinement of absolute chronological dating methodologies, including Optically Stimulated Luminescence and Amino-acid techniques.

iii. Ongoing development of geomorphological models of terrace formation and river valley evolution, including improved interaction between the geomorphological and archaeological communities.

iv. Further development of geoarchaeological models of artefact transportation in a variety of sedimentary regimes.

v. Targeting of field monitoring of aggregates extraction sites, with specific reference towards sediment dating, geoarchaeological models, and recording of key sedimentary phenomena.

Module 8 Outline

Module 8 Results

Module 8 Interm Report

References

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