NOTES OX THE GEOLOGY OF THE GULF OF 



ST LAWRENCE 



BY JOHN M. CLARKE 



THE DEMOISELLES OF ENTRY ISLAND 

 On the ]\Iagdalen islands in the Gulf of St Lawrence the higher 

 land elevations are mammiform hills which rise everywhere with 

 striking symmetry and entire absence of irregularities into softly 

 contoured grassy domes. I have termed these hills demoiselles,^ 

 taking the name from Demoiselle hill, one of their number, which 

 fronts the sea on the east coast of Amherst island. Over all the 

 larger islands these pretty hills rise to relatively notable heights ; 

 except for them the islands are flat, low-lying plateaus of sandstone 

 and sand dune, but the rounded heads of the demoiselles, showing 

 none of their rocks except where eaten into by the sea or weather, 

 command the eye by the abruptness with which they rise from the 

 plain. W^herever they occur all have the same general direction and 

 relation to each other. Their course lies generally northeast-south- 

 west, like the trend of the island group itself. On the broad central 

 part of Amherst they lie in well-nigh parallel rows, but their height is 

 pTeatest on Entry island. St Lawrence hill (so named by S- G. W. 

 Benjamin, author, forty years ago, of some fascinating sketches of 

 these islands) approximates 670 feet and is the highest of all and 

 the most symmetrical in the remarkable array of demoiselles in that 

 island to which I desire, among other things, to direct special atten- 

 tion. On Amherst these hills lack some of the elements of sym- 

 metry and beauty which are presented by those on Alright and 

 Entry islands. It is in the latter they attain their most striking 

 appearance and on Alright their greater isolation makes them a some- 

 what more effective feature to the passerby. Indeed the passer 

 seldom sees the hills of Entry except as a skyline, for this island 

 lies apart from the rest of the group and from all regular con- 

 nection with them. The steamer threads the precarious channel 

 between the sand spits of Amherst and Entry but the hills of Entry 

 are on its farther side and face the gulf. In my general description 

 of the islands and their geology the nature of these hills was dis- 

 cussed and some suggestions made as to their origin, but much was 

 left unsaid. Since then I have had opportunity to study the structure 

 of Entry island, which I had not before visited. 



^ Observations on the Magdalen Islands, 1911, p. 12. 



Ill 



