Wessex Archaeology was commissioned by De Romein Nearshore, on behalf of NeuConnect Britain Ltd, to report on a Palaeolithic geoarchaeological evaluation and associated geoarchaeological monitoring of Ground Investigation (GI) works carried out along the route of the NeuConnect onshore DC cable route and the Horizontal Directional Drilling (HDD) works area. The cable route and HDD works are located at Grain on the Isle of Grain, Kent. The evaluation area is centred on National Grid Reference (NGR) 588327, 176917 (TQ 88327 76917). The evaluation was carried out in accordance with a requirement for archaeological evaluation outlined in Condition 22 (i) of approved planning application MC/21/2483. The purpose of the evaluation was to establish requirements for further archaeological work needed to comply with Condition 22 (ii) of the approved planning application, which outlines a requirement to mitigate against impacts of the development on any significant archaeological remains, or to provide information for a management plan to prevent impacts. In consultation with the County Archaeologist for Kent County Council (KCC), archaeological advisor to the Local Planning Authority (LPA), it was established that the principal archaeological risk of the development was impacting on Pleistocene geological deposits containing significant Palaeolithic geoarchaeological remains (artefacts and sediments with potential to preserve palaeoenvironmental evidence). The program of evaluation and monitoring comprised the excavation and recording of six geoarchaeological test pits, with associated assessment for Palaeolithic geoarchaeological evidence; geoarchaeological monitoring, recording and assessment of three GI boreholes; geoarchaeological review of three GI borehole logs, and the production of a deposit model, which incorporated all relevant, available deposit records. The program of evaluation and monitoring comprised the excavation and recording of six geoarchaeological test pits, with associated assessment for Palaeolithic geoarchaeological evidence; geoarchaeological monitoring, recording and assessment of three GI boreholes; geoarchaeological review of three GI borehole logs, and the production of a deposit model, which incorporated all relevant, available deposit records. The evaluation and monitoring established that Quaternary geological deposits are absent from large areas of the HVDC cable route and onshore HDD works area, with Made Ground overlying London Clay Formation bedrock being present in most locations. Locally Sands and Gravels between 0.20m and 1.0m thick unconformably overlay bedrock and were sealed by made ground. The lithology of the Sands and Gravels was consistent with being fluvial Pleistocene sediments, but no clear evidence demonstrating that these were in situ sediments (e.g. fluvial bedding structures) was identified, and they may be recently redeposited. If in situ, these Sands and Gravels are the basal remnants of a Thames-Medway river terrace, which has been truncated by previous aggregate extraction and which are likely to be broadly equivalent with deposits investigated to the south-west at the site of the NeuConnect Converter Station and Substation (Wessex Archaeology 2024). At the Converter Station and Substation site these terrace deposits were dated to MIS 9-7 (337-191 Kya) and demonstrated to locally contain late Lower/early Middle Palaeolithic archaeology. No archaeology was identified from the Sands and Gravels during the evaluation, and they had low potential for preserving palaeoenvironmental evidence. Based on the results of the evaluation, the Palaeolithic geoarchaeological potential of the sands and gravels was assessed to be low.
Shaw et al. (Mon,) studied this question.