Palaeogeography of Atlantic Canada 13-0 kyr

We combine isobase maps with a digital terrain model of Atlantic Canada to map coastlines from 13 C-14 kyr BP to the present. At 13 C-14 kyr BP there are ridges of high relative sea level (rsl) values over Newfoundland and the Maritime Provinces, and a re-entrant of low values in the Gulf of St. Lawrence. This pattern persists well into the Holocene, and reflects crustal response to the slow wasting of ice caps that persisted in Newfoundland and the Maritime Provinces for up to five millennia after the removal of ice from the Gulf of St. Lawrence by a migrating calving embayment. The palaeogeographic reconstructions reveal an archipelago on the outer shelf, from Grand Bank to the continent, that persisted from >13 C-14 kyr BP until ca. 8 C-14 kyr BP. Much of the Magdalen Shelf was exposed, but the Magdalen Islands were never connected to the mainland. Prince Edward Island was initially separated from the mainland, became connected after 11 C-14 kyr BP, and was separated again just before 6 C-14 kyr BP, when Northumberland Strait formed. The reconstructions are highly sensitive to relatively small changes in isobase values, especially on the shallow banks on the continental shelf. (C) 2002 Published by Elsevier Science Ltd.