SDO21221 - The Moors at Arne Coastal Change Project: Detailed Gradiometer and Electromagnetic Induction Survey Report

‘A detailed gradiometer and electromagnetic induction (EMI) survey was conducted over land north of Arne Road, Wareham, Dorset (centred on NGR 394915 086850). The project was commissioned by Kier Infrastructure with the aim of establishing the presence, or otherwise, and nature of detectable archaeological features in support of the Poole Harbour Habitat Creation Project (PHHC). The site comprises areas of moorland. The geophysical survey was undertaken between 17 August and 11 September 2020. The geophysical survey was successful in identifying a range of anomalies of possible archaeological and geoarchaeological interest. However, large portions of the site were difficult or impossible to survey. The gradiometer survey has identified a range of magnetic anomalies that may relate to archaeological features. In the majority are associated with small pit or ditch-like features of an uncertain origin. They are predominantly located atop of higher points within the landscape on outcrops of Poole formation deposits. Within Area 11 and 15, there are several stronger (thermoremanent) anomalies which are interpreted as evidence for in-situ burning. These are likely associated with industrial activity, such as a kilns or furnaces possibly pertaining to salt production. A number of other anomalies in the gradiometer survey are interpreted as pertaining to probable paleochannels. These are located in areas of alluvium and have been identified in the Compound Area, Area 9, and Area 15. However, the majority of features of geoarchaeological interest have been identified by the EMI survey. The EMI survey has shown a demonstrable difference in conductivity between the alluvial deposits at the eastern end of the site and the tidal flat deposits in the west of the. In addition, a number of areas of higher conductivity are thought to relate to former channels or undulations in the subsurface deposits. In the western part of the site, higher areas of conductivity and increased magnetic susceptibility may relate to the presence of peat. Although further investigation would be required to confirm this, these areas have significant potential to contain paleoenvironmental remains that are of geoarchaeological interest. The EMI survey has identified a metal feature within Area 5. This likely lies below or next to a test pit (MDTP209) dug in the area to a depth of 2.3 m. It is not possible to comment on the size or shape of the feature, but it is thought to lie above a depth of 4.2 m.’