The coast of Maine is divided into 4 distinct geomorphologic sections arising from differences in the composition, orientation and structure of the bedrock (Kelley et al., 1988) (Figure 1). The salt marshes located in these 4 sections of the coast are somewhat distinct geomorphologically due to differences in geology, the sediment supply and composition, and the intensity and direction of wave energy. The Arcuate Embayments compartment (in the southwest region of the state) is characterized by resistant bedrock headlands separated by large sandy beaches and large back barrier marshes. Moving further east, the Indented Shoreline compartment is characterized by high grade metamorphic rocks that have been gouged out by glaciers into elongate peninsulas and islands oriented N/S to NE/SW and mudflats and salt marshes.The Island-Bay Complex shoreline is composed largely of igneous rocky shorelines and islands with relatively high exposure to waves and fewer salt marshes. Finally, the Cliffed Shoreline, in downeast Maine, is characterized by cliffs of volcanic rock and few salt marshes.
Johnson, B., Bohlen, C. C., Gunn, C., Beirne, E., Barry, C., Craig, M., & Dostie, P. (2016). Ecogeomorphology of two salt marshes in midcoast Maine. Portland, ME: University of Southern Maine, Muskie School of Public Service, Casco Bay Estuary Partnership.