Monument record MDO18640 - Fire Headquarters, County Hall, Colliton Park; Roman quarry pits

A series of interconnecting large quarry pits, cut into chalk bedrock, was identified across the western half of the site during excavations at County Hall in 1984. Neither the full vertical nor horizontal extent of the pits was established, although the base was recorded at one point at a depth of 1.66m. The earliest pottery recovered from the backfill dated from the 1st-2nd century AD, although this may be residual. It is likely that the quarries were dug for either the construction of the town ramparts, for the burning of lime for building purposes from the 2nd century onwards, or for the construction of the town walls in the 3rd century AD.

Found during the excavations carried out by Wessex Archaeology in 1984 prior to construction of the New Fire Headquarters at County Hall, Dorchester (1) (2). The numbers in square brackets below refer to the context and feature numbers used in the published report (2). The quarry pits were cut into the chalk bedrock in the western part of the site for the purpose of extracting chalk. The full extent of the pits was not established and the base was examined at one point only, where a depth of 1.66m into the chalk was attained. The date of the quarrying is difficult to determine from direct archaeological evidence. The earliest date of pottery contained in the later backfill is 1st-2nd century AD, although much of the material on site is thought to be residual. It is only a possibility then, that the quarrying took place before the end of the 2nd century. Both the construction of ramparts in this area in the 2nd century and the preparation of lime mortar for building from the 2nd century onwards would have provided a need for bulk extraction of chalk. It is also possible that the extraction of chalk for lime may have been required for the construction of the town walls in this area, probably in the 3rd century. The deposits infilling the quarries were observed in six places, and contains two distinct types of material: in the north and north-east, chalk and stone rubble; while in the south and south-east, ash and burnt residues. The latter fills may coincide with the positions of two previously recorded hearths (3) and a further one contained in building [250]. This confirms that the quarries were still in the process of being infilled during the use of the smithing furnaces, probably in the later 3rd-early 4th century.

Record last edited

Jun 30 2014 4:28PM