NHER 42156 (Monument record) - Possible medieval extraction pits

November 2005. Norfolk NMP.
A group of possible extraction pits is visible as cropmarks on aerial photographs (S1), (S2), (S3) and (S4), centred at TG 4662 2314. Extraction in this area of the Upper Thurne Valley may have been for clay or peat, or for both, as outlined by Williamson in ‘The Broads’ (S5). It presumably took place during the medieval period, prior to the rise in relative water levels that brought to an end large-scale extraction of this type. Alternatively, the cropmarks could have formed over geological anomalies, or over naturally formed pools which have since silted up. Parts of their edges, however, appear regular and sharp enough to suggest that the features were a product of human activity.

The cropmarks, which are frequently rather indistinct, appear to have formed over extensive areas of wetter ground. The clearest comprises an elongated area approximately 500m long and up to 225m wide. Its approximate location, shape and size corresponds with a pond depicted on Faden’s 1797 Map of Norfolk (S6) and on Bryant’s map of 1826 (S7). The cropmark of the southern end of this feature is only clearly visible on aerial photographs taken in 1946 (S3) and its appearance is rather different to the northern part, suggesting that this end may have been dug to a shallower depth. To its north (centred at TG 4639 2354) is a possible second, smaller pit; to its south (centred at TG 4681 2310) a sub-rectangular cropmark extends eastwards across a substantial drain and into the unimproved grassland of Horsey dunes. Further to the south (clustered around TG 4687 2284) several smaller and more fragmentary areas of possible extraction are visible. These could have once formed part of a single large pit but the cropmarks are not clear enough, and the area is too fragmented by drains, for them to be mapped as a single entity.
S. Tremlett (NMP), 16 November 2005.