Origin of the Bay of Fundy, an interpretation from sub-bottom profiles

Brief Field Guide to Intertidal Sediments, Minas Basin, Nova Scotia

“…Consequently it has been assumed that the tidal range has increased dramatically during this period, and indeed, this seems consistent with evidence presented by Swift and Borns (1967) and Grant (1970), summarized by Greenwood and Davidson-Arnott (1972), and further discussed below.…”

“…They were interpreted by Churchill and Crosby as marine intertidal sand bars formed at a time when sea level stood higher than at present. In the light of the early Holocene history proposed by Swift and Borns (1967) and Grant (1970), these bars assume a significance not apparent to earlier workers. Were they formed as hypothesized by earlier workers, by large tides in an earlier, more extensive Windsor Bay?…”

“…The cause of the very large tidal range is generally stated to be resonant amplification of the semidiurnal tidal component (e.g., Proudman, 1952;Swift and McMullen, 1968). Studies by Redfield (1950), Harleman (1966), Rao (1968) and Yuen (1969), however, suggest that the resonant period of the Bay of Fundy itself is by no means coincident with the semidiurnal period of 12.42 hrs.…”

“…The bedrock geology of the eastern part of the area was described by Weeks (1948). Swift and Borns (1967) have described evidence from the north shore of Minas Basin that early glaciomarine sands deposited by ice-contact deltas ("Advocate Harbour Member") were succeeded by fluvial outwash ("Saints Rest Member"): the two members together form the raised Pleistocene terrace observed along much of the north shore. "Formation of the terrace started with dissipation of the ice... Outwash deltas replaced ice in the valleys of the north shore as the rising sea level flooded them as far as the Cobequid scarp.…”

“…Tidal velocities are extreme in the Minas Passage reaching 11 knots (5.7 m/sec), are generally 3 to 4 knots (up to 2 m/sec) in the open basin and decrease near the shore to a maximum of 1 to 3 knots over the main sand bodies (Swift and McMullen, 1968;Klein, 1968Klein, , 1970. Much of the Minas Passage is underlain by bedrock, swept bare of sediment by the strong tidal currents (Swift and Lyall, 1968a and b) .…”