| Title: |
Evaluation at Severnside West Pipeline Diversion South Gloucestershire |
| Series: |
Oxford Archaeological Unit unpublished report series
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| Downloads: |
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oxfordar1-515835_211643.pdf (5 MB)
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| Biblio Note |
This report was uploaded to the OASIS system by the named Publisher. The report has not been reviewed by the relevant HER. The report has been transferred into the ADS Library for public access and to facilitate future research.
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| Licence Type: |
ADS Terms of Use and Access
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| DOI |
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| Publication Type: |
Report (in Series)
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| Abstract: |
An array of twenty evaluation trenches, each measuring 30m x 2m, was excavated across the route, representing a 4% sample of the area (Fig. 4). The trenches were positioned to investigate the potential impacts along the route of the pipeline. The aims of the trial trenching was to investigate fully and expose the entire vertical extent of all trenches to this depth. The trenches were excavated using a mechanical excavator under archaeological supervision and were positioned on anomalies identified from the geophysical survey, in order to establish the date, nature, vertical and horizontal extent and significance of any archaeology. A proportion of the trial trenches were also located to investigate areas without geophysical anomalies in order to test the efficacy of the geophysics and ensure that the issue of the presence/absence of archaeological remains was resolved. Some trenches were split into sections in order to maintain stability, reduce flooding and minimise risks to personnel. In particularly deep deposits such as the crossing of the Red Rhine (DX6) and roads (RDX1 and RDX2) depths were anticipated be at least 4m and consequently a series of four test pits and four boreholes was undertaken to evaluate the deeper impact areas. The boreholes were drilled using a terrier rig with continuous sleeved core recovery. The test pit were dug with the mechanical excavator. In June 2015 Oxford Archaeology undertook an archaeological evaluation along the route of the proposed Severnside Pipeline Diversion, South Gloucestershire. The work was commissioned by Jacobs on behalf of the National Grid. The primary purpose of the evaluation was to assess the archaeological potential of the route of the proposed pipeline diversion. The site lies upon extensive estuarine alluvial deposits known as the Wentlooge Formation, which underlie large areas of both the English and Welsh sides of the Severn Estuary. In the Enron site to the south, a thin peat layer containing a comminuted charcoal in-wash was radiocarbon dated to the early Bronze Age. Although no evidence of human activity accompanied this deposit, previous work to the north-east of the site had provided evidence of Romano-British settlement. A geophysical survey was undertaken prior to the intrusive works that suggested low archaeological potential, with mainly services and geological changes revealed. The archaeological evaluation comprised the mechanical excavation of 20 trenches measuring 30m by 2m, comprising a 4% sample of the proposed route. The trenches were positioned to investigate the results of the geophysical survey and to investigate areas that had been unavailable at the time of the survey. In addition, four geoarchaeological test pits were excavated within the trenches, and four boreholes, in order to map the underlying sediments and to investigate the presence/extent of any charcoal and peat layers. Several undated ditches were identified in the north-west area of the route and have been interpreted as drainage ditches associated with post-medieval cultivation. The remaining trenches were devoid of archaeological remains and only ceramic land drains and clearly modern features were recorded. The geoarchaeological test pits and boreholes showed an alluvial sequence across the route consistent with the Middle to Upper Wentlooge Formation. A layer corresponding precisely with a charcoal layer previously found to the south was mapped across the area. The layer is interpreted as a humified incipient vegetation layer, which in the west and south of the site was very dark and contained microscopic charcoal (but no in situ burning), whilst further east the layer became more humic and peaty. No archaeological finds or features were found in association with this layer. Based on the result of the evaluation, the archaeological and palaeoenvironmental impact of the proposed pipeline diversion is considered to be low. |
| Author: |
Carl Champness
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| Publisher: |
Oxford Archaeology
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| Year of Publication: |
2015
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| Locations: |
| County: |
Gloucestershire |
| County: |
South Gloucestershire |
| District: |
South Gloucestershire |
| Country: |
England |
| Parish: |
Almondsbury |
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Grid Reference: 355499, 182499 (Easting, Northing)
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| Identifiers: |
| OASIS Id: |
oxfordar1-515835 |
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| Source: |
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| Created Date: |
30 Nov 2023 |
