Archaeological fieldwork at Eversley Quarry, Fleet Hill Farm, Finchampstead, Berkshire documented evidence of Mesolithic activity, associated with paleoenvironmental deposits, on the Blackwater River floodplain, a river for which activity of this period was previously unknown. The discovery evolved from initial recognition of worked flint artefacts across a well weathered, stripped subsoil surface in part of the site. Additional material was collected subsequently from the summit of an adjacent low knoll. The findings were of sufficient extent and importance to warrant supplementary archaeological fieldwork using a gridded test pit strategy to evaluate the Mesolithic potential in remaining parts of the site. This resulted in the identification of additional clusters of worked flints, which were preserved in situ.

The clusters were predominantly of Mesolithic date but also included Neolithic and Bronze Age artefacts, indicating prolonged use of the landscape. Concentrations were consistently located on slightly elevated sand bars flanking palaeochannels of a formerly braided river system. The contemporaneity of the palaeodrainage and Mesolithic activity has been confirmed by radiocarbon dates from peat that formed during the Holocene. The collective results mark a significant contribution to knowledge of the Blackwater River valley, a major communications artery in the Mesolithic period linking the west end of the Wealden Greensand to the Rivers Thames and Kennet. These findings also highlight the importance that river valleys can make to locations that have been less well studied but nevertheless enjoyed prolonged use.