York Historic Environment Record

The boreholes identified a sequence of deposits, with the eariest consisting of pre-medieval deposits, ranging in thickness from 0.70m to 1.8m, forming a layer between approximately 0.55m–3.74m OD although dating was not certain due to lack of dateble artefacts. Deposits attributed to the medieval period, following the damming of the River Foss and the creation of the King’s Fishpool, were predominantly organic, waterlogged, laminated silts and clays. These deposits appear to have accumulated slowly under wet conditions. This was a substantial build-up of material ranging in thickness from 1.70m to 3.75 (being in excess of 3m thick in all but one borehole), and encompassing a depth range from 2.04m to 7.05m OD across the site. The post-medieval period differed significantly from earlier waterlogged material, being drier with more domestic and building debris forming a horizon 1.3m–1.7m at depths between 6.70m OD and 7.24m OD. This may represent deliberate attempts to consolidate and build-up the ground level to reclaim formerly boggy, waterlogged land. The top 1.80m to 2.55m of deposition comprised rubble and soils, likely relating to 18th and 19th century gardens and houses in the area. The uppermost layers related to the formation of the 20th century motor garage and current ground surface.