292 



Antigonish to McAra's brook. 



The town of Antigonish (alt. 40 ft., 12 m.) is situated 

 in the valley of Right river which follows what is apparently 

 an ancient depression, now partially filled with the Car- 

 boniferous rocks of the McAra's Brook and Ardness for- 

 mations, the latter of which immediately underlies the 

 town. Less than a mile to the north of Antigonish the 

 surface rises rapidly to the plateau, here underlain by the 

 James River rocks, through which protrudes a core of 

 diabase forming the elevation known as Sugar Loaf hill 

 (alt. 760 ft., 213 m.). This portion of the plateau is 

 separated from the larger area to the west by a lowland 

 whose surface rocks belong to the McAra's Brook forma- 

 tion and through this lowland the Gulf road follows the 

 valleys of Right river and Malignant brook to Malignant 

 cove. Outcrops are not common. About two miles 

 south of the Malignant cove shore the quartz porphyry 

 of McNeil's mountain rises to the west of the road to an 

 elevation of 1,010 feet (307 m.) while about a mile north 

 the rhyolite hill of Sugar Loaf ascends to 680 feet (207 m.). 

 At Malignant cove, a conglomerate, probably of Ordovician 

 age forms the surface rock and may be seen at the Malig- 

 nant Brook bridge crossing. For the first half mile west 

 of Malignant cove the road is underlain by this conglome- 

 rate after which the Silurian forms the surface rock to 

 McAra's brook. 



McAra's brook and the shore section east to 

 Arisaig point. 



Just above the bridge crossing at McAra's brook are 

 splendid exposures of the sandy shales from which Ami 

 obtained his Old Red Sandstone (Knoydart) fossils. 

 Below the bridge the hard red shales and grey sandstones 

 are exposed in the bed and along the bank. A road along 

 the west bank of the brook leads to its mouth, where the 

 shore clififs are formed either of the McAra's Brook 

 conglomerate or the diabase intrusives by which it is cut. 

 about a mile to the west the rocks of the Ardness formation 

 form the cliffs, while the farthest headland visible from 

 this point is in part built of the Pennsylvanian? conglo- 

 merates. McAra's brook reaches the sea by a gateway 

 cut through a diabase dyke, on the seaward side of which 



