PEE-CAEBONIFEROUS ROCKS OF SAGHUEST NEOK. 287 



80° E., at the line of faulting separating this rock from the arkose series.^ 

 A short distance east of this fault line the rock contains a diabase dike. 



It will be noticed that about halfway between the southern termina- 

 tion of the greenish conglomeratic rock and the arkose promontory the dip 

 changes from steep east to steep west. North of the point the exposures 

 seem to be successively lower. Southward toward the fault line appar- 

 ently higher horizons are reached. Close observation, however, shows no 

 signs of a fold there, where the steep dips change direction. A strong 

 flexure in the rock previous to the faulting which exists farther westward 

 seems to be the explanation, the flexure being of such a character that at a 

 certain point the conglomeratic strata are nearly vertical. North of this 

 point they dip westward; south of this point, eastward. 



Exposures of the greenish conglomerate also occur on the hillside 

 toward the southern part of the line of shore exposures. A line connect- 

 ing the extreme shore exposures west and south would trend N. 22° E., 

 and would pass just west of the most western of the hill exposures. 



The position of the conglomerate with reference to the greenish shales 

 is uncertain, but after detailed work on this question it was supposed to 

 overlie the same, owing to the westward dip of the series northward 

 toward the Island Rocks. 



While the shales have the ordinary clastic appearance the conglomeratic 

 beds present certain - peculiar features. In the first place, the pebbles are 

 usually decidedly angular in appearance, presenting, commonly, the aspect 

 of fragments in a breccia. In the second place, there seems to be no mai-ked 

 tendency to arrange the fragments in layers according to size, as is commonly 

 the case when fragments are transported by water action. In the third place, 

 a large part of the fragmental material is lighter or darker in color than the 

 cementing material when seen on the weathex-ed surface of the I'ock. When 

 broken, however, this distinctness to a great extent disappears, and the whole 

 mass looks greenish, varying chiefly in fineness of grain. This is a feature 

 more commonly observed in breccias than in genuine conglomerates. In 

 the fourth place, the variety of material occurring in the form of fragments 

 varies sufficiently to include four or five types. Some of these fragments 

 seem to be certainly from some clastic rock. Others may be of igneous 



' Prof. T. Nelson Dale raises the very pertinent question whether the facts may not be explained 

 by assuming an uneonfoimity, since Carboniferous arkose wonld probably rest m an unconformable 

 mannei npon Cambrian shale. 



