Geophysical Survey at Grimsby II Solar Farm

All survey work was completed to appropriate standards, as outlined by existing guidelines (CIfA 2014a, revised 2021; 2014b, updated 2020a; CIfA 2019, CIfA 2020c, Schmidt et al. 2015). The gradiometer survey was completed using Bartington Grad601-2 and Sensys FMG650 magnetic gradiometer systems with data logger. Readings were recorded at a resolution of 0.01 nT and data collected with a traverse interval of 1 m and a sample interval of 0.2 m. The survey data was collected on site by traversing in increments utilising a cart system to achieve the best possible results. Real Time Kinematic (RTK) differential GPS equipment was used to accurately determine the position of the survey equipment and monitor data. Sensors were left to acclimatise outdoors prior to balancing at the start of each day's survey. The processing was undertaken using TerraSurveyor64 software and consisted of standard processing procedures. Illustrations were created using QGIS software. Interpretation of identified anomalies was achieved through analysis of anomaly patterning and increases in magnetic response and was aided by examining the available supporting information. The interpretations follow Ecus colour coding and categorisations of anomalies and attempt, where possible, to suggest the nature of the buried feature. The geophysical survey produced usable data of the fields under study, though some areas are obscured by the masking effect of ferrous readings. Three foci have been identified. The first, a series of curvilinear, rectilinear and linear anomalies to the east of Field 1 have been interpreted as evidence of a probable Iron Age or Romano-British settlement site. The second area is in Field 3 and consists of several probable enclosures as well as an alignment of small pit-like anomalies likely indicating an earlier boundary feature. The third area is in Field 4 where there are several curvilinear, rectilinear and linear anomalies to the north and south of the field, which has also been interpreted as another probable Iron Age or Romano-British settlement site. Furthermore, the previously noted pit-alignment in Field 3 continues north into the southern area of Field 4 also. A third pit-alignment is also visible to the north of Field 4, which runs perpendicular. Numerous disarticulated curvilinear, rectilinear and linear anomalies are noted throughout the northern portion of Field 3 and within the centre of Field 4. These are less confidently interpreted as anthropogenic in origin, although this cannot be ruled out due to their proximity to anomalies of likely archaeological origin. The same can be said for numerous positive pit-like anomalies recorded throughout the dataset. There is evidence of historic agricultural activity across Fields 2 and 4 in the form of ridge & furrow cultivation. Further modern, agricultural drains are also visible throughout the Site. A large service pipe is also visible in the northern portion of Field 4. Variations of the underlying geology are also visible in Fields 2 and 4, however these correspond to changes noted on BGS mapping. Other anomalies correspond with recorded features in the historic OS maps of 1888-1913. Both historic and modern agricultural activity is also clearly visible in the data in the form of ridge and furrow and a network of field drains.