Assessing 3D metric data of digital surface models for extracting archaeological data from archive stereo-aerial photographs.

Archaeological remains are under increasing threat of attrition from natural processes and the continued mechanisation of anthropogenic activities. This research analyses the ability of digital photogrammetry software to reconstruct extant, damaged, and destroyed archaeological earthworks from archive stereo-aerial photographs. Case studies of Flower's Barrow and Eggardon hillforts, both situated in Dorset, UK, are examined using a range of imagery dating from the 1940s to 2010. Specialist photogrammetric software SocetGXP® is used to extract digital surface models, and the results compared with airborne and terrestrial laser scanning data to assess their accuracy. Global summary statistics and spatial autocorrelation techniques are used to examine error scales and distributions. Extracted earthwork profiles are compared to both current and historical surveys of each study site. The results demonstrate that metric information relating to earthwork form can be successfully obtained from archival photography. In some instances, these data out-perform airborne laser scanning in the provision of digital surface models with minimal error. The role of archival photography in regaining metric data from upstanding archaeology and the consequent place for this approach to impact heritage management strategies is demonstrated

Denudation of the continental shelf between Britain and France at the glacial-interglacial timescale

The erosional morphology preserved at the sea bed in the eastern English Channel dominantly records denudation of the continental shelf by fluvial processes over multiple glacial-interglacial sea-level cycles rather than by catastrophic flooding through the Straits of Dover during the mid-Quaternary. Here, through the integration of multibeam bathymetry and shallow sub-bottom 2D seismic reflection profiles calibrated with vibrocore records, the first stratigraphic model of erosion and deposition on the eastern English Channel continental shelf is presented. Published Optical Stimulated Luminescence (OSL) and C ages were used to chronometrically constrain the stratigraphy and allow correlation of the continental shelf record with major climatic/sea-level periods. Five major erosion surfaces overlain by discrete sediment packages have been identified. The continental shelf in the eastern English Channel preserves a record of processes operating from Marine Isotope Stage (MIS) 6 to MIS 1. Planar and channelised erosion surfaces were formed by fluvial incision during lowstands or relative sea-level fall. The depth and lateral extent of incision was partly conditioned by underlying geology (rock type and tectonic structure), climatic conditions and changes in water and sediment discharge coupled to ice sheet dynamics and the drainage configuration of major rivers in Northwest Europe. Evidence for major erosion during or prior to MIS 6 is preserved. Fluvial sediments of MIS 2 age were identified within the Northern Palaeovalley, providing insights into the scale of erosion by normal fluvial regimes. Seismic and sedimentary facies indicate that deposition predominantly occurred during transgression when accommodation was created in palaeovalleys to allow discrete sediment bodies to form. Sediment reworking over multiple sea-level cycles (Saalian-Eemian-early Weichselian) by fluvial, coastal and marine processes created a multi-lateral, multi-storey succession of palaeovalley-fills that are preserved as a strath terrace. The data presented here reveal a composite erosional and depositional record that has undergone a high degree of reworking over multiple sea-level cycles leading to the preferential preservation of sediments associated with the most recent glacial-interglacial period

Ireland: Submerged Prehistoric Sites and Landscapes

Evidence of Ireland's drowned landscapes and settlements presently comprises 50 sites spread across the entire island. These comprise mainly intertidal find spots or small collections of flint artefacts. A handful of fully subtidal sites are known, generally from nearshore regions and consisting, with one exception, of isolated single finds. Evidence of organic remains is also sparse, with the exception of Mesolithic and Neolithic wooden fish traps buried in estuarine sediments under Dublin. The relatively small number of sites is probably due to lack of research as much as taphonomic issues, and thus the current evidence hints at the potential archaeological record which may be found underwater. Such evidence could contribute to knowledge of the coastal adaptations and seafaring abilities of Ireland's earliest inhabitants. Nonetheless, taphonomic considerations, specifically relating to Ireland's history of glaciation, sea-level change and also modern oceanographic conditions likely limit the preservation of submerged landscapes and their associated archaeology. Realistically, the Irish shelf is likely characterised by pockets of preservation, which makes detection and study of submerged landscapes difficult but not impossible. A range of potential routes of investigation are identifiable, including site-scale archaeological survey, landscape-scale seabed mapping, archival research and community engagement

The stratigraphy and chronology of the fluvial sediments at Warsash, UK: implications for the Palaeolithic archaeology of the River Test

This paper reports new fieldwork at Warsash which clarifies the terrace stratigraphic framework of the Palaeolithic archaeology of the region. Sections were recorded in former gravel pits and at coastal locations, supplemented by the use of ground penetrating radar and luminescence dating techniques. The region’s extensive borehole archive was also analysed to produce a revised terrace stratigraphy at Warsash and for the Test valley as a whole. At Warsash, some of the sediments previously identified as the Mottisfont/Lower Warsash Terrace are reassigned to the Hamble, Belbin/Upper Warsash and Ganger Wood/Mallards Moor Terraces. A luminescence dating programme, using test procedures not utilised in earlier dating studies in the region, yielded age estimates for the Hamble and Mottisfont/Lower Warsash Terraces at Warsash and also highlighted the complicated nature of the fluvial sediments of the River Test, suggesting that published luminescence ages for these deposits should be treated with some caution. This study indicates that the data used to construct terrace stratigraphies also requires careful assessment. The use of bedrock height and sediment thickness data produces more coherent long profile correlations than those produced by terrace surface data alone. The revised terrace stratigraphy provides the framework for the Palaeolithic archaeology at Warsash and clarifies correlations within and between archaeologically important sediments of the Test Valley, enabling it to contribute to discussions on the Lower-Middle Pleistocene settlement history of southern Britain

225 King Georges Avenue, Southampton. Archaeological Watching Brief (SOU1753) (OASIS ID: wessexar1-284916)

Wessex Archaeology was commissioned by E and H Property Investment to conduct an archaeological watching brief as part of development on land at 225 King Georges Avenue, Southampton The development consisted of the erection of a 2-storey side extension to the building following the demolition of an existing garage and works. The archaeological watching brief monitored the excavation of foundation trenches for the new extension The stratigraphic sequence observed consisted of natural underlying geology viewed at a depth of 1.50m below ground level (8.15m aOD), this was subsequently overlain by a buried subsoil and topsoil and then a thick band of modern made ground. This layer of made ground is likely to have been laid down during the construction of the houses during the 1930s or 1940s to raise the ground level above and alleviate the riskr of flooding from Tanners Brook which lies only some 40m to the west of the site. No archaeological features or deposits were observed during the course of the archaeological watching brief

High House, Purfleet, ARC HHP 97

Wessex Archaeology was commissioned by Union Railways Limited to carry out an archaeological evaluation on a site at Purfleet, Essex (centred on URL grid point 36750 58125; NGR grid point TQ 56750 78125), known as High House. The potential for archaeological remains within the site had been identified by an earlier Environmental Statement (URL 1994) which included fieldwalking (URL 1995) and geophysical prospection (URL 1996). This potential was defined as the possibility of discovering subsoil features and deposits of archaeological interest which may be associated with, or in close proximity to, surface artefact concentrations recorded during fieldwalking or anomalies recorded during geophysical survey, and also the possibility of finding a continuation of the possible late prehistoric enclosure noted in the evaluation of the adjacent Palaeolithic site

Wrecks on the Seabed R2: Assessing Evaluating and Recording (U86)

The project comprised the development and testing of a number of methodologies for the rapid assessment, evaluation and recording of wreck sites. The main aim of the project was to provide industry, regulators and contractors with a framework for the incremental, decision-oriented investigation of wreck sites and with guidance on their archaeological assessment, evaluation and recording. The objectives were: - Develop and refine methodologies for assessing, evaluating and recording sites in deeper water. - Assess the effectiveness of undertaking archaeological recording using remote operated vehicle (ROV) and geophysical techniques only. - Assess environmental issues (e.g. depth, distance from port, fetch) in respect of working on sites in deeper water. - Assess infrastructure issues (e.g. anchoring, tow cable handling, umbilical handling) in respect of working on sites in deeper water. Year two of Round two of the Wrecks on the Seabed project comprised deep water ROV survey of three wrecks. This dataset relates to the third of these wrecks, a First World War German U-boat - U86 - and comprises databases relating to the Wessex Archaeology DIVA dive recording system, GIS shapefiles for the tracklogs of the ROV and video stills from the survey

Coombeshead Farm, Diptford, Devon (OASIS ID: wessexar1-167261)

Trial trench evaluation comprising 16 trenches targeting geophysical anomalies, including large sub-oval enclosure. Trenching recovered slight dating evidence suggesting that the enclosure is Romano-British. Other features revealed included shallow ditches or gullies, a posthole and a pit; no dating evidence was recovered from any of these features