The Bay of Fundy has a complex postglacial history and the high tides that now make it famous are the result of a relatively recent process known as tidal amplification. This is nicely expressed by marine geologist Gordon Fader:

“Tidal amplification commenced around 6000 ybp when the outer banks of the Gulf of Maine (Georges and Browns) were finally flooded and submerged (Grant 1970). As a result of the development of high tides, increased erosion of the seabed commenced. Fine-grained sands were redistributed and deposited over till and glaciomarine sediment particularly in the inner Bay of Fundy. Sand waves formed in localized fields covering 30% of the inner Bay of Fundy seabed. Former glacial till surfaces below the low sea level stand were subjected to stronger bottom flow and continued to be winnowed and armoured with lag gravels.” (Fader 2005, p.9)

Tidal amplification played a major role in the development salt marsh on the Upper Bay of Fundy. The increasing tidal currents transported a portion of the redistributed fine-grained sands mentioned by Fader to coastal areas in the Bay where “Salt Marsh Hay” (Spartina patens), "Black Rush" (Juncus gerardii ), and other salt tolerant plants common to salt marshes started to grow. New developments in postglacial history for the time period back to 6000 ybp are therefore of up most importance to those who study the various salt marsh topics. An important recent development, reported in the August 2010 issue of the Canadian Journal of Earth Sciences, involves a hypothesis that a barrier once extended across the entrance to Minas Passage from Parrsboro to Blomidon and that its destruction over a period of a few hundred years, due to an increase in the tidal amplitude, fits well with the Mi’Kmaq Legend of Glooscap.(Shaw, Amos, Greenberg, O’Reilly, Parrott, Patton, p.1080). The article provides the following information on the Glooscap Legend.

"A useful source for this legend is Beck (1972), who states that:

It came to pass in those days that the beavers had built a dam across from Utkoguncheek or Cape Blomidon, to the opposite shore, and thereby made a pond that filled all the valley of Annapolis. [p. 112.]

Beck was advancing the possibility that these legends were folk memories of the former existence of the Pleistocene giant beaver Castoroides ohioensis. She went on to describe how Glooscap broke the beaver dam:

And when the dam was cut from where it joined the shore there was a mighty rush of many waters, so that it swung round to the westward, yet it did not break from the other shore. Therefore the end of it lodged with a great split therein where the flood had found a free course, and the hole may be seen there still, even to this day, and may be seen by all who of those who pass up the bay; and this point, or Cape Split, is called by the Micmacs Pleegun, which being interpreted, means the opening of a beaver dam. [p. 112.]

We would argue that this oral legend attests to the destruction of a barrier across Minas Passage, an event thatwas observed by First Nations peoples ~ 3400 years ago." (Shaw, Amos, Greenberg, O’Reilly, Parrott, Patton, p.1090)

Physiography of Minas Passage based on multibeam bathymetry. The dashed lines show the barrier that may once have extended across the entrance to Minas Passage.

Link 1: Scour Trough in Minas Passage

Link 2: Suggested configuration of Minas Basin during the early Holocene..

Link 3: Suggested configuration of Minas Basin during the early Holocene..

Reference

Beck, J.C.(1972). The giant beaver: a prehistoric memory? Ethnohistory (Columbus, Ohio), 19(2): 109–122. doi:10.2307/481746.

Shaw, John , Amos, Carl L., Greenberg, David A. , O’Reilly, Charles T., Parrott, D. Russell, and Patton, Eric ,(2010).Catastrophic tidal expansion in the Bay of Fundy, Canada, Can. J. Earth Sci. 47: 1079–1091

Fader, Gordon,(2005).Glacial, Post Glacial, Present and Projected Sea Levels, Bay of Fundy, Atlantic Marine Geological Consulting Ltd. 2901 Parkdale Avenue Halifax, Nova Scotia B3L 3Z2