A stratigraphic transect across Romney Marsh

Prior to the establishment of the Romney Marsh Research Trust, our knowledge of the sediments recorded at depth below Romney and Walland Marshes was relatively limited, with the only major source of material being the Soil Survey Memoir published by R.D. Green in 1968. However, during the last decade, a series of research programmes, funded by the RMRT, has enabled a number of detailed local studies of the Marsh sediments to be made. Some members will recall, for example, Professor Tooley demonstrating the sediments recorded in the Broomhill area, and more recently, the demonstrations given by Dr. Plater at Denge Marsh, and Dr. Innes and me at the Midley Church bank.

A characteristic of this research has been the collection of detailed, high quality stratigraphic data at a local scale, and this has provided a basis for our now much improved understanding evolutionary history of of the the Marsh. However, as more and more data have been collected from local sites, so there has come the need to integrate these results into a broader spatial context. This was the objective of this particular project, which aimed to complete a line of cores across the entire width of the Marsh from north to south, linking a number of sites, previously studied in detail at a local scale.

The starting point for the transect was Horsemarsh Sewer, and the end point Broomhill Level. Both sites have previously been studied by Professor Tooley, and more recently by Dr. Jim Innes. The transect of cores passed south, across The Dowels, over the Rhee Wall near Snargate, down to Brookland, over the White Kemp Sewer, to Cheyne Court Farm, and eventually ended at Broomhill Level. Cores were sunk by hand, using the new equipment purchased by the RMRT, and the sediments recorded to a depth of up to 7 metres. A sample core was collected from Brookland, which is a mid 'way site between Horsemarsh Sewer and Broomhill. This core has been analysed for its diatom and pollen content, and radiocarbon dated.

The results of this deeper survey have established, for the first time, an overall stratigraphic framework for the deeper sediments of Marshes. Romney and Walland The main Marsh peat, which members of the Trust may occasionally see in the bottom of ditches across the Marsh, extends across most of Romney and Walland Marshes. The peat began accumulating at the inland fringe, at Horsemarsh Sewer, at about 5000 years ago, and had spread to Brookland by 4400 years ago. At this time, sea-level was still rising quite quickly, and for the peat f orming communities to have developed, an early form of the Dungeness barrier must have been established across Rye Bay by this time.

Pollen analysis of the peat indicates that at the beginning of peat accumulation, the environment was dominated first by saltmarsh plants and then freshwater reedswamp conditions. These were then replaced by an alder carr, which probably existed at the site for several thousand years. Towards the end of the peat formation, the alder carr was replaced by sedges, and finally saltmarsh conditions once more, as the sea returned across the Marsh about 2000 years ago.

During the stratigraphic survey an additional, hitherto unknown, channel was discovered to the south of Brookland. This channel appears to be up to 800m in width, which is comparable in size to the former Wainway Channel. More work is required to track the course of this feature, and to establish its age, but it may represent a former course of the River Rother, which has not previously been identified. The results of this survey are still being analysed, but when completed, I hope that they will contribute significantly to our understanding of the evolution of Romney Marsh.

Antony Long