INTRAFORMATIONAL CORRUGATED ROCKS 591 



Gaspe in the Gulf of St. Lawrence, called attention to a remarkable 

 example of intraf ormational corrugations. Logan says : 



It wotild. appear as if the layers, after their deposit, had been contorted by 

 lateral pressure, the underlying stratum remaining undisturbed, and had then 

 been worn smooth before the deposition of the next bed. Where the inverted 

 arches of the flexures occur, some of the lower layers are occasionally wanting 

 as if the corrugated bed had been worn on the under as well as the upper side. 

 The corrugations are precisely in the direction of the dip, and the peculiarity is 

 not confined to a small part of the deposit. 



He states that the same structure occurs at localities a mile apart. 



Fig. 3. — Contorted strata within Devonian limestone at Cape Gaspe, Quebec. 

 (After J. M. Clarke.) 



John M. Clarke, who has observed the Gaspe occurrence, and 

 who has kindly permitted the use of the accompanying picture 

 (Fig. 3), says: 



Crinkled strata lying between strata which show no evidence of dislocation 

 are not of infrequent observation but, in most of the recorded instances, the 

 crinkled layer is of softer stuff (that is, a highly aluminous mud rock) than the 

 rigid beds above and below. The brilhant exhibition of this phenomenon on 

 the chffs of Cape Gaspe, first sketched by Sir William Logan, is not of this 

 character. Here the middle deformed beds are of thin hmestone leaves like 

 those which bound them. They are crumpled into sharp, much involved and 

 overlapping curves in which the hmestone plates are broken sharply across. 

 It seems very doubtfvil if any other explanation can be brought forward for 



