York Historic Environment Record

Monitoring of geoarchaeological boreholes to evaluate the nature of the deposits beneath a jetty-structure known as the Castle Mills island. Boreholes 1 and 2 were not archaeologically observed; in these sandstone bedrock was reported at 10 to 11m BGL (-3 to -4m AOD) beneath a clayey silty fill. In borehole 3, the rig operators encountered bone and pottery at between 9 and 9.7m BGL (-1.7 to -2.4m AOD). A quantity of Roman pottery and animal bone had been recovered from a soft-plastic, very clayey silt which appeared to be highly organic in nature. The animal bone was black and bore butchery marks, and there were small fragments of leather. The pottery provides a date range of 1st to late 3rd century AD, and the whole is clearly a Roman deposit.