Cold water of near normal marine salinity penetrated into eastern Scottish firths for a few hundred years early in the Windermere Interstadial, but thereafter conditions in the Firth of Tay and the innermost Firth of Forth became more brackish, probably because of falling sea-levels and estuarine infilling. The impoverished macrofaunal assemblages dominated by Nuculana pernula and Yoldiella lenticula resemble those of present-day high-boreal to arctic soft bottom communities associated with high rates of deposition, but several temperate molluscs known from contemporary deposits in the Clyde area are apparently absent. Deposition of mud was locally >20 mm per year in the firths of Forth and Tay, and >7 mm per year in the Cromarty Firth. These figures are comparable to those obtaining both in offshore estuarine basins during the decline of sea-level from the highest Flandrian raised beach in the Firth of Forth and in proximal glaciomarine environments elsewhere.

You do not currently have access to this article.