Discovery of a second Roman quarry in Hertfordshire for manufacture of querns from Paleogene Hertfordshire Puddingstone siliceous concretions

Abstract The discovery of a Roman quarry for recovery of Hertfordshire Puddingstone was first reported by Lovell and Tubb (2006) , from the Colliers End Paleogene outlier in the east of the county. Hundreds of querns are known to have been manufactured from the distinctive pebbly siliceous concretions renowned as Hertfordshire Puddingstone. The existence of further sources of the raw material has been obvious ( Green, 2016 ), but quarries have proved elusive, and surface extraction from isolated boulders has been a possibility. However a further concentration of Roman pits has now been discovered in the west of the county, in the Paleogene outlier at Great Gaddesden. The evidence for quarrying is introduced in a regional geological and archaeological context. Plans for more detailed work are summarised.