Monument record TQ 67 SE 1327 - A compacted briquetage floor recorded north-east of Shornemead Fort

A compacted briquetage floor was recorded standing slightly proud of the surrounding foreshore silts. Briquetage refers to the fired‑clay structural components used in Roman salt‑making, such as supports, pedestals and pan fragments. In this case, the surface formed a firm, rammed layer of crushed briquetage clasts, rising approximately half a metre above the adjacent silts. A scoured exposure in 2018 revealed the internal structure of the deposit, showing it to be a deliberately laid working surface rather than an amorphous waste dump. To the east, small quantities of black, reduced coarseware sherds were embedded in the silt, though these were undiagnostic.

The briquetage floor sealed earlier salt‑making debris, most notably SMF 02, and is interpreted as a working platform associated with an intensively used saltern operating during the mid‑second century AD. Beneath the floor, at a depth of between 0.5 and 1.0 m, excavators recovered a Colchester‑type mortarium, a fine, flanged mixing bowl widely distributed in Roman Britain. Mortaria of this class—dating to approximately AD 140–180/190—provide a secure terminus post quem for the construction of the surface. The mortarium’s deliberate placement suggests it may represent a foundation deposit, echoing practices recorded at other Roman industrial sites.
The wider geomorphological context indicates that the floor was constructed on a bedding layer likely containing charcoal, paralleling examples known from salterns along the Medway. The feature lies within an eroding alluvial sequence and occupies a position immediately overlying and adjacent to SMF 02, with SMF 01— a deposit of mid‑second‑century domestic ceramics—located nearby, implying a tightly integrated complex of salt‑making and associated domestic or support activities.

By the mid‑2020s the briquetage surface was undergoing active erosion. Its elevation above the surrounding silt made it particularly vulnerable to tidal scour, storm damage, and ship‑wash, and substantial loss of fabric was anticipated within only a few years of 2025. Given its fragility, recommended actions include creating a detailed photogrammetric record, taking micromorphological monolith samples to study the construction and use of the floor, and conducting targeted sampling of the briquetage itself to identify plant impressions or tempering materials that may further illuminate the operational techniques of the Roman saltern. (1)

<1> Steve Trim, 2026, SHORNE/HIGHAM THAMESIDE ROMANO-BRITISH SITES 2012-2015+, SMF (03) (Unpublished document). SKE58794.