Plate 51 



Massive granite of the Canada Hill granite type exposed by excavation 

 trench for a cut-and-cover stretch of the Catskill aqueduct at Continental- 

 ville. (Compare with plate 50 which is the commonest associated type). These 

 are practically all gradations between the simple massive habit of this gran- 

 ite and the plainly bedded structure of the clearly distinguished Grenville 

 sediments. 



