Archaeological test pitting works were undertaken in the courtyard to the rear of Seagate Castle, Irvine to inform on the potential impacts of the insertion of a new drainage route. Four test pits (labelled A1 to A4) were excavated along the proposed route of the new drainage track and soakaway running southwest-northeast from the northeast wall of the castle. Test Pits A1 and A3 measured 1m� in plan and were excavated to a depth of 450 and 640mm from the current ground surface respectively, while A2 measured 1m by 2m and was excavated to a depth of 540mm. A4 was positioned over the proposed site for a new soakaway and measured 3m� excavated to a depth of 1m, with a further 1m� sondage excavated at its centre to a depth of 940mm. The test pits encountered made ground deposits throughout, reaching the full depth of Test Pits A1, A2 and A3. A4 revealed made ground deposits to depths of between 700mm and 1m, before encountering a layer of potentially windblown sand. Underlying this at 1.3m below ground level, a series of natural beach gravel deposits were revealed within the lower sondage. Four features were uncovered within the upper portion including a small clay-lined pit and the slate base of a culvert, which all post-dated the occupation of the castle. Three of the features may relate to major repair works undertaken at the site in the 19th century, while the fourth was a modern animal burial. The artefact assemblage recovered during the works includes over 400 sherds of pottery with origins spanning from the 13th through to the 20th centuries: a rich assemblage dispersed throughout the made ground deposits representing centuries of occupation.
Claire Williamson (2023) studied this question.