Mineralogy and Geology of Nova Scotia. 375 



finally changes to a black rotten stone, that soon crumbles 

 into sand, leaving, as it decays, those semi-oval and hemi- 

 spherical cavities which may be often observed on the surface 

 of our trap rocks. Rolled and worn pieces of soft slate are 

 also sometimes found embedded in whinstone, which also 

 sometimes holds a very small quantity of pyrites, almost 

 always crystallised in those regular forms to which the term 

 of marcasites has been applied. 



Where hills of whinstone are nearly bare, perpendicular 

 ledges may often be observed, running in an easterly and 

 westerly direction, and facing the south. Upon ascending 

 the ledge, there is either a level or a gentle descent extending 

 northerly for, perhaps, a hundred yards, when we meet with 

 another ; and in this manner they continue often for a quarter 

 of a mile or farther. 



In describing the situation of the whin which alternates 

 with slate, it is necessary to observe, that there is a strip of 

 land on the shore of the Bay of Fundy, commencing near 

 St. Mary's Bay, and extending to Cobiquid, varying from 

 five to twenty miles in breadth, which has a deep soil, with 

 but little stone on the surface, and which generally rests upon 

 rocks that I have not yet mentioned. With the exception 

 of this strip of ground, and the granite and whinstone dis- 

 tricts already noticed, nearly the whole of the land south* 

 west of a line from the middle of the township of Rawdon, to 

 the middle of the great Shubenacadie Lake, and from thence 

 to Lawrencetown, and the greater part of the land within 

 ten miles of the shore from Lawrencetown to Manchester, 

 rests upon a rock which is alternately slate and whinstone. 

 The surface of ground that rests upon slate is usually covered 

 with broken whinstone for half a mile southward from the 

 line of junction of a band of it with whinstone. Where 

 either of these kinds of rock lies south of a mass of granite, the 

 surface stones, for a considerable distance, are granite. When 

 the soil is removed from these rocks, the slate frequently, 

 and the whinstone in some places, appear to have a smooth 

 surface, marked with lines which seem to have been formed 

 by the attrition of some hard substance moving in a north 

 and south direction. Some of these lines are near an inch in 

 depth, others only slight scratches. Mr. Whiteman, whose 

 business has given him many opportunities of observing them, 

 informs me, that he has sometimes observed them upon 

 granite, and that he has always found them to bear near 

 north and south direction in every part of the province 



(To be continued.) 



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