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episodes of Aeolian erosional and redepositional cycles have pushed machairlandforms eastwards at the expense of adjacent lochs, marshes and peatcovered ‘black land’ (Ritchie 1986).Raised marine shorelines3.1.3 Well-formed marine platforms typical of those formed within the west coast ofmainland Scotland are not readily identifiable along the eastern coastline ofNorth Uist owing to past glacial modification, land submergence and theprevalence of dune formation. Where rocky platforms exist these are eithercovered by a mantle of glacial till or cover sands, which are likely to containre-deposited elements of the earlier raised beach deposits.Sand dunes3.1.4 The climate of north-west Scotland has been instrumental in both theformation of, and as an agent of change for, the machair. Prevailing anddominant winds are from the south and north-west and it is no coincidence thatmost of the dune and machair areas are located on coasts exposed to thesedirections (Angus & Elliot 1992). Sand dune formations are extensivethroughout the study area. The island of Bernerary at the northern end of thestudy area (Fig *) is dominated by machair and sand dune formation along thelength of its Atlantic coastline. Ritchie (1970) estimates that machair covers55% of the island of Bernerary. Sandhills and dunes are prominent within theVallay and Orasaigh areas and further south at Balranald and southwards toBaleshare. These areas are characterised by impressively high dune cliffs.Smaller pockets of dune formation are typical within the small shelteredcrescent-shaped bays. Scolpaig beach is a typical example where intertidalrock platforms flank the outer-bay area with a well-formed dune situated at thebay head.Coastal wetlands and mudflats3.1.5 The development of coastal saltmarsh is confined to more sheltered areas awayfrom the direct impact of wave attack and commonly present within the tidalcreek environments. Prominent areas of saltmarsh include that at TraighBhàlaig (NF 8700 7500) flanking a sheltered tidal inlet. Similar formationswere seen at Dun na Maribhe (NF 8630 7470) alongside a freshwater drainageoutlet. North of Cuithe Lachlainn (NF 7980 7556) wide intertidal sandflats arebacked by saltmarsh between rocky intertidal platforms. On the west side ofthe island of Baleshare saltmarsh extends for about 3.5 km and owes itspresence to the shelter afforded by the extensive dunes fronting the westernside of the coastline. This type of formation acts as a buffer zone at theMHWM and is susceptible to undercutting and slope failure. Coastalsaltmarsh provides good grazing land and as such it is prone to erosion bycattle. However, saltmarsh present in Erosion Cell 12 appeared stable, actingas a buffer between the shoreline and the hard coast edge.UISN/1051/011CFA