A beach ridge plain is a progradational strand plain composed of a series of parallel beach ridges. The ridges are commonly closely spaced, the bottoms of the interridge swales commonly being at about the normal elevation of the back of the beach before the prograding ridge was formed in front of it (Stapor, 1975).
Changes in the trend commonly affect sandy shorelines. These cause diagonal, curving, or end truncation of the beach plain, with a new progradational series forming parallel with the changed shoreline.
The ridge may originate immediately back of the active beach as a flood-level ridge commonly of the coarser beach materials, or it may form as an eolian accumulation caught in the vegetation immediately back of the beach proper. Many beach ridges are water-laid below and eolian above, or there may be alternations of the two types, as in the plain at the mouth of Sabine Lake (bay), Texas. Where excess amounts of sand are blown to it from the beach, the ridge may become hummocky, deserving to be called dunes, with the ridge becoming a foredune.
Beach ridge plains occur as cuspate forelands , deltaic forelands , and at the mouths of incoming streams that break through a chenier plain depositing sand in the line of a dominantly clay plain (Otvos and Price, 1979).
The swales are commonly dotted with rain ponds and may be dark with organic materials. Locally swales may be partly filled with sand from the ridges.