NORTH SYDNEY AND SYDNEY MINES, C. B. — DfAVOLFE. 291 



harbor, shows sinkhole topography and blind streams, there 

 are none here. The Millstone Grit section is undulating but 

 iv general more elevated than the others. In some places it 

 rises sharply from the harbor to a height of one hundred and 

 eighty feet, and its average elevation is about one hundred. 

 Betweeai Sawmill lake and Limestone creek, at an elevation of 

 one hundred and thirty feet, two square miles are covered with 

 swamp and bog. Althoug-h low land occurs on all sides in 

 adjacent territory, the ground here remains wet throughout the 

 year. 



In the Coal ]\Ieasures the average elevation is approximately 

 eighty feet. Owing, however, to the much greater exposure to 

 marine action, the shore cliffs are higher than farther west. 



Special interest attaches to the topography of the land north 

 and northwest of Cranberry Head. From Black point the 

 surface slopes down to Big pond. The shores of this body, 

 beside which the jSTova Scotia Steel and Coal Company have 

 built their furnaces, are low and in some places even swampy. 

 On the north side of the pond is the new colliery (Sydney No. 

 3). Stretching down to the shore on the east is a level bog, 

 covering about three square miles. This swamp evidently was 

 once the bed of a post-glacial lake, in all probability somewhat 

 above sea level. A shore section of the bog shows that it rests 

 in part, at least, upon l)edrock. How much the shore has l)een 

 cut back by wave action at this point, and Avhere the initial 

 shoreline of subsidence stood, it is impossible to say. But the 

 bed of the lake, then probably filled up as now by vegetation, 

 was brought practically to sea-level; and in three places the 

 cross-section of the bog is exposed to marinei erosion. 

 Headlands on either side of the swamp have also suffered rapid 

 loss by this agency. But where the erosion is most rapid — at 

 Cranberry Head and Black point — tlie cliffs are lov.-ering; for 

 the land as a whole slopes inland and toward the bog rather 

 than seaward. 



Pkoc. & Tkans. N. S. Inst. Sci., Vol XI. Tkans T. 



