ON RECENT EARTHQUAKE IN CAPE BRETON. BY D. S. 

 MclNTOSH, B. A., M. Sc., Lecturer on Geology, Dal- 

 housie University, Halifax, "N. S. 



Head 14th February, 1910. 



On the afternoon of December 20th, 1909, about three 

 o'clock, a distinct earthquake shock was felt in a part of Inver- 

 ness county, Cape Breton. The disturbed area embraced Port 

 Hood, Mabou, Inverness, Lake Ainslie, Whycocomagh, and 

 Orangedale. From beyond these localities it is not reported. 

 In the towns of Port Hood and Inverness, it was thought that 

 an explosion had taken place in the mines. At Lake Ainslie 

 it is said that a fracture was made in the cement walls of a 

 cellar by the shock. Mr. A. Stirling McLean thus describes it at 

 Orangedale : "While not destructive or terrifying in any way, it 

 was quite pronounced in this locality. One could feel the whole 

 building trembled in a sort or rapid vibratory motion. Tin- 

 ware 'and crockery on shelves danced at a great rate. The 

 shock lasted for about five seconds long enough for one to 

 realize what was taking place. A loud rumbling noise was 

 distinctly heard before the shock which was thought by s'ome 

 persons to be that of an approaching train, by others that of a 

 flue on fire." 



The disturbance would appear to have been merely local. 

 At no place on the Island, other than those referred to does it 

 seem to have been noticed. On account of the small area 

 affected, the seat of the disturbance would not likely be far 

 removed from the surface. Nor would it likely be found in 

 the igneous rocks which outcrop in a few places, and probably 

 underlie the younger rocks of the district. Did a fault take 

 place in these rocks, the effect would likely be more wide- 

 spread than the recent occurrence. The cause of the shock is 



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