Section IV, 1919 [33] Trans. R.S.C. 



The Glacial History of Prince Edward Island and the Magdalen Islands 



By A. P. Coleman, M.A., Ph.D., F. R.S.C. 



(Read May Meeting, 1919.) 



The literature shows a considerable diversity of opinion as to 

 how far Pleistocene land ice encroached on the shallow water of the 

 Gulf of St. Lawrence, some believing that Prince Edward Island and 

 the Magdalen Islands were not touched by it, and others, that the 

 Labrador sheet swept across Gaspé and continued southeastwards to 

 Cape Breton Island and the mainland of Nova Scotia. The most 

 extensive description of the Pleistocene geology of the region is that 

 of Chalmers in 1894. He states that the west end of Prince Edward 

 Island was at least touched by ice from New Brunswick, but that the 

 rest of the island was not covered by it. He thinks there may have been 

 local glaciers upon parts of it and that floating ice deposited boulders 

 on its lower shores during a time of depression at the end of the Ice 

 Age. The Magdalen Islands he believes were never glaciated, though 

 a few foreign boulders were deposited by floating ice on the north- 

 western shores^ In regard to the Magdalens, his conclusion that 

 they were unglaciated is shared by Richardson and Clarke. 



On the other hand, Goldthwait, in 1915, suggests that the Labra- 

 dor ice sheet pushed southeast across the shallow floor of the gulf 

 between Gaspé and Nova Scotia, leaving boulder clay on Amherst 

 and other islands of the Magdalens and reaching Nova Scotia. 



The present writer visited the islands in 1918 with the object of 

 studying the superficial geology so as to settle the matter if possible; 

 but no attempt was made to cover their Pleistocene features in detail. 



Pleistocene Deposits of Prince Edward Island 

 A visitor landing on Prince Edward Island from the Tormentine 

 ferry and going by rail to Charlottetown sees a red loamy soil free 

 from boulders, resting on decaying red sandstones, as if residual; and 

 no other features of the general landscape or the railway cuttings 

 suggest the action of ice. In places rock comes close to the surface, 

 there are no morainic forms visible, there is only one small lake on 

 the island, and the rivers are mostly well graded; so that one is in- 

 clined to think that Prince Edward Island escaped glaciation. Very 

 little that could be interpreted as proving ice action was found in the 

 central parts of the island, but going northwestwards from Summer- 



' Gaol. Surv. Can., Vol. VII, New Series, 1894, pp. 39 M, etc. 



