Colchester Archaeological Trust

CAT Report 576: summary

An archaeological watching brief on land to the south of ‘Serenity’, 6 High Street, West Mersea, Colchester, Essex - July 2010
by Adam Wightman

Date report completed: December 2010
Location: land to the south of 6 High Street, West Mersea, Colchester, Essex
Map reference(s): TM 00985 12433 (c)
File size: 109 kb
Project type: Watching brief
Significance of the results: *
Keywords:

Summary. CAT undertook a watching brief in July 2010 on land to the south of 6 High Street, West Mersea, Essex. The plot is on a steep southwards slope towards the Blackwater Estuary and was formerly the back garden of the aforementioned property. The site work comprised the construction of a new detached dwelling with an access drive and a garage. The development site is located on the southern side of West Mersea in an area of high archaeological potential. It lies 100m south-west of the Church of St Peter and St Paul, underneath which survive the remains of a Roman villa (EHER nos 2214 and 2274). Roman walls, mosaics and tessellated floors have been recorded since the 18th century in the vicinity (EHER nos 6533-6534) and are believed to form part of an extensive complex of buildings. The site of a medieval Benedictine monastery also lies immediately west of the church and a number of human skeletons have been found in the area (EHER nos 2187 and 12546). Prior to the first visit by a CAT employee, the new access road had been excavated, a terrace had been excavated into the slope, the piles for the new building had been installed and the eastern half of the foundation trenches had been excavated. The new access road was approximately 5.5m wide and was excavated to a depth of up to 0.7m below the modern ground-level. The edges of the road cut were exposed and were examined. The road had been excavated through topsoil (L2, approximately 350mm deep) and into the natural sand and gravel (L4). No archaeological features or deposits were identified. The excavation of the terrace onto which the new property was to be built had involved the removal of soil and ballast from part of the slope to a maximum depth of approximately 2m. The excavated material had been placed further downslope to widen the terrace and create the area onto which a patio was to be constructed. The stratigraphy of the northern edge of the terrace was recorded and examined for finds where gaps in the supporting steel shuttering permitted. The dark grey sandy-silt topsoil (L2) was 0.8m thick and contained modern building material and geotextile sheeting. L2 probably covered most of the slope prior to construction. Beneath L2 was a lighter sandy-silt (L3). This layer could be an early soil accumulation, but based on the thickness of the deposit (approximately 1m) and the relative heights of the natural L4 (see below), it was probably imported to landscape the slope down to the estuary from the area of the church. Nine fragments of Roman brick/tile and a fragment of peg-tile were recovered from L2/L3 and from L3. L3 overlay natural orange sand/gravel (L4) that did not appear to be redeposited. A CAT archaeologist made four visits whilst the western half of the foundation trenches for the new building were being excavated. The trenches were excavated to a depth of c.1m below the level of the terrace. The whole terrace had been covered in a layer of geotextile material and crushed concrete prior to the commencement of works (L1). The foundation trenches for the northern half of the new building were excavated through natural sand and gravel into orange natural clay (L4). In the southern foundation trenches, L3 and possibly L2 overlay the natural sand/gravel. Once a trench had been excavated, shuttering was immediately installed and the poly-frames were placed between the piles. This was due to the volume of ground water resulting from recent poor weather conditions and the proximity of the site to the estuary. No archaeological deposits were identified or artefacts recovered from the foundation trenches. The different depths at which the natural sand/gravel L4 was observed appeared to support the idea that the slope down to the estuary had been landscaped and that soil had been imported to create a gentler slope. This explains the presence and depth of L3 on the slope and its absence on the plateau at the top. During the examination of the upcast soil from the groundworks, further Roman brick and tile was recovered as well as two fragments of Roman pottery and two fragments of medieval pottery. It cannot be said for certain whether these finds, or any of those recovered from L2 and L3, were incorporated in the imported soil of the slope or whether they originate from activity on the slope during these periods.