Evidence for a postglacial low relative sea-level stand in the drowned delta of the Merrimack River, Western Gulf of Maine

A submerged delta of the Merrimack River, located offshore between Cape Ann, Massachusetts, and the New Hampshire border, indicates a postglacial low relative see-level stand of about −47 m. The low stand is inferred to date to 10,500 yr B.P., but a lack of age control makes this assignment uncertain. A curve based on a late Wisconsinan, high relative sea-level stand of +32m at 13,000 yr B.P., a low stand of −47m at 10,500 yr B.P., and younger radiocarbon dates related to sea-level rise indicates an early postglacial crustal rise of at least 5 m per century.