Morden Bog, NNR Decoy Pond - Palaeoenvironmental Assessment Report

Wessex Archaeology

A targeted geoarchaeological borehole survey was undertaken in and around the Decoy Pond at Morden Bog National Nature Reserve (NNR), Decoy Heath, Wareham. A total of 28 hand auger boreholes were undertaken using a Russian corer. Borehole WA-25a was selected as the master sequence for palaeoenvironmental assessment. A second borehole, WA-10a, was also radiocarbon dated for chronological comparison against the deposits in WA-25a.

The sequence of deposits at the Site comprised well preserved plant remains in a peaty matrix, overlying humified peat, in turn overlying coarse Sands. These Sands are considered likely to represent fluvial deposits of either Upper Pleistocene or early Holocene date, and form the topographic template upon which the organic deposits of Holocene age accumulated. The organic deposits are widespread both within and outside of the pond, and form part of the sequence that has accumulated during the Holocene in a stream valley draining south towards the River Piddle. No basal (e.g. clay) lining to the pond was identified during the borehole survey, and on the basis of the expected age of the underlying Sands, it is considered unlikely that a lining was used in the construction of the pond