During excavations associated with the construction of two blocks of new dwellings on land at 135 All Saints Avenue in Margate, a prehistoric silt deposit was exposed, which had possibly been laid down in a waterlogged environment was encountered.

The features encountered in the excavation largely respected the edge of a deposit which may be the result of the deposition of fine silts in a semi-waterlogged marshy, land-surface. The area is known to have been subject to waterlogging and periodic inundation from high sea levels until recent times. The 'mere' element of the place name Mere-gate reflects the general recognition of these characteristic conditions over a long period of time. Several worked flints and some fragments of non-local stone, possibly quern fragments, were recovered from different levels within the silt deposit implying a prehistoric origin for the material. The excavation area is located at a meeting point between two different landscape types; where dry land abuts the edge of a waterlogged environment of streams, pools and salt marshes.

The deposit was encountered within all of the evaluation trenches and further explored in the area excavation of the Eastern Block. In evaluation Trench 1 and Trench 2 the deposit extended over a large proportion of the area of the trenches. As the deposit was mechanically reduced in Trench I several natural hollows and gullies filled with the material were encountered. Curving gully cut 107 was filled by the deposit and sealed beneath the general spread of deposit 103. The feature contained one find of a nodule of burnt flint Two further irregular features, apparently natural hollows, cut109 and cut 110 were also encountered in Trench 1, both were filled with the dark silty deposit. Finds of flints and stone were recovered from throughout the deposit in Trench I and 2. The deposit was shown to extend into the open area excavation of the Eastern Block along the western edge gradually thickening from east to west and from north to south. The deposit directly overlay the natural brickearth forming a limit to the archaeological features encountered. The deposit was sampled by excavation in two areas

During the watching Brief sections show the silt deposit was of a fairly consistent thickness over the area although its depth below ground level varied slightly over the site. In some areas a leached pale grey deposit of similar material was observed immediately below the deposit and may have been continuous with it. The fine silt layer was sealed by a clean subsoil deposit and generally overlay natural brickearth or chalk geology. An environmental sample of the deposit taken from the excavation of the east Block area contained a small amount of charred wood and cereal grains but no conclusive evidence that would point to the environmental or ecological conditions in which the deposit was formed, a previous processing of a sample from Trench I of the evaluation produced no flot. It is possible that the deposit was formed in a rapid flooding episode which graded soils it collected through mechanical action, dropping the fine silt as the flood reached a very low energy state. Any organic material may have been washed out of the soil and deposited in another fraction elsewhere. The silt deposit represents an unusual soil phenomenon not noted in other excavations in Thanet and although it has not been possible to characterise it fully it has contributed some evidence to the emerging picture of the environmental conditions that existed during the pre-historic period. (information summarised from source) (1)

<1> Trust for Thanet Archaeology, 2005, 135 All Saints Avenue, Margate, Kent: Archaeological Assessment Report (Unpublished document). SKE24006.