The problem of a late quaternary landbridge between Britain and Ireland

The question of whether a possible landbridge(s) existed between Britain and Ireland during Devensian (Midlandian) Late-glacial and Holocene time is analysed in the light of new geological and related environmental information. The problem of landbridge definition as a whole and related palaeogeographic reconstruction is reviewed briefly, particularly in relation to present understanding of the mechanisms conditioning sea-level movements and marine inundation of former land areas. A tentative palaeoenvironmental reconstruction is made for the Irish Sea and neighbouring seas from Late-glacial time onwards. Suggestions are put forward for the lack of a long Quaternary sedimentary record in Ireland. From the palaeoenvironmental data, it is concluded that no land links are likely to have existed via routeways across the southern continental shelf or Irish Sea zones. If any landbridge existed, it could only have operated between the north of Ireland and South West Scotland as a discontinuous linkage, formed by temporary islands at levels >-46 m O.D. The timing of its operation, if at all, is placed at ∼11,400 to 10,200 ± 200 BP.