192 



concluded, apparently on lithologic grounds, that they are 

 synchronous. 



The slate in the Paradoxides quarry is greenish-gray, some- 

 what silicious, fine-grained, and remarkably uniform. Mi- 

 nute grains of pyrite are pretty generally diffused. In the 

 quarry the rock is apparently only very coarsely jointed ; but 

 the weathered surface reveals much finer division by this means. 

 The stratification is very massive and can hardly be detected, 

 except by means of the trilobite remains ; these may be sup- 

 posed to lie in the plane of the bedding, and according to this in- 

 dication the strike is E.-W., and the dip S. 80°-85°. Across 

 the strike, southerly, the slate, still apparently maintaining a 

 high dip in that direction, is met at a distance of perhaps three 

 hundred feet by fine-grained grayish and reddish Huronian 

 granite, while on the west the same granite cuts off the slate 

 at about twice the above distance from the trilobite quarry ; 

 that is, the contact of the two formations, as shown on the map, 

 is oblique to the strike of the slate. 



Following this line of strike directly across Weymouth Fore 

 River to Mill Cove, we find substantially the same relation of 

 granite and slate. The small tongue of land projecting into 

 the cove on the east is composed of granite similar to that on 

 Hay ward's Creek, and this rock outcrops at several points be- 

 tween the cove and the second street east. This boundary is not 

 accurately represented on the map, for on the line of the street 

 mentioned the granite extends as far north as the brook. The 

 slate, which succeeds the granite on the north, though not seen 

 in actual contact with it, the nearest outcrops of the two rocks 

 being several rods distant, is in part very similar to the Para- 

 doxides slate ; but this variety is interstratified in thin beds with 

 a purplish-brown and chocolate-colored slate, which is the pre- 

 vailing type. The strike varies from E.-W. to N. 70° W. ; 

 while the dip is southerly and very steep, above 80°. Much of 

 the slate is characterized by a well-marked cleavage, which shows 

 a northerly dip of 70°-80°, and greatly obscures the bedding. 



The elongated amygdaloidal vesicles or nodules, however, 



