Late 12th to early 14th century estuarine silt or buried ploughsoil, Othona Community Site (EHER 14430)

Trial trenching in 1991 and subsequent excavation in 1992-1993 recorded a thin silty clay loam which overlay the archaeological features below the topsoil. It was equated with that identified in the 1864-1865 (EEX351) and 1947 (EEX352) excavations of the fort (EHER 31) which was first interpreted as a post-Roman ploughsoil of 12th-13th century date. It is probably a estuarine silt which had been affected by early medieval agricultural activities.

1991. Trial trenching. Overlying all the features and the natural subsoil, was a thin silty clay layer which was partially removed during the machine-stripping of the site. However, it could be seen in section to have formed a uniform layer, from 10 to 2cm thick, just below the topsoil. The finds from this layer included late Roman, Saxon and early medieval pottery. The layer has been interpreted as a buried ploughsoil, on the basis of its consistency and texture. Also many of the features below it were very shallow and give the appearance of having been truncated. The finds from the layer appear in greatest quantity where it covers buried features, suggesting that the finds are derived from the underlying, plough-damaged features. The stratigraphic evidence shows that the ploughsoil must date to no earlier than 1200 AD, but there were no finds in it dating from the later medieval or post-medieval periods. It is of interest that the 1864-1865 (EEX351) and 1947 (EEX352) excavations which took place within the fort itself, also revealed a 'black loam', which was interpreted as a post-Roman ploughsoil of 12th-13th century date. It seems likely that the buried plough soil found during the evaluation and the 'black loam' layer from within the fort are the same. The evidence therefore suggests that this layer of ploughsoil can be dated to the late 12th to early 14th centuries. <1> <2> 1992-1993. Archaeological excavation. Below the topsoil, but overlying the Roman and prehistoric features, the layer of silty clay loam recorded during the evaluation was again observed. Seventeen test pits were hand-excavated through this, 2% of the total area. The intention was to recover data that might indicate the origin of this layer and its date. The finds recovered date to the Roman and medieval periods; the Roman finds (which are the most numerous) are thought to derive from the truncating of underlying Roman features. The medieval pottery dates to the 13th-14th centuries AD. The soil micromorphological study of the layer found it to be a probable estuarine silt, that had been affected by early medieval agricultural activities. <3>