Hence the coast as a whole is irregular, with numerous embayments, peninsulas and islands; and in Maine this irregularity reaches a disadvantageous climax.
A section of the coastal plain, from North Carolina to southern New Jersey, resembles the plain farther south in general form and quality of soils, but besides being narrower, it is further characterized by several embayments or arms of the sea, caused by a slight depression of the land after mature valleys had been eroded in the plain.
There is good reason for believing that at least along the southern border of New England a narrow coastal plain was for a time added to the continental border; and that, as in the New Jersey section the plain was here stripped from a significant breadth of inland overlap and worn down so as to form an inner lowland enclosed by a longitudinal upland or cuesta; and that when this stage was reached a submergence, of the kind which has produced the many embayments of the New England coast, drowned the outer part of thy plain and the inner lowland, leaving only the higher parts of the cuesta as islands.
Although the Coast Prairie is a sea bottom of very modern uplift, it appears already to have suffered a slight movement of depression, for its small rivers all enter embayments; the larger rivers, however, seem to have counteracted the encroachment of the sea on the land by a sufficiently active delta building, with a resulting forward growth of the land into the sea.
Most of the recent movements appear to have been upward, for the coast presents few embayments such as would result from the depression and partial submergence of a disse~ted mountain range; but three important exceptions must be made to this rule.