Mr Jukes on the Geology of Newfoundland, 107 



slaty cleavage imperfectly developed, the whole series being 

 characterised by as few features of interest as can well be ima- 

 gined. It seems somewhat to change in the nature of conglo- 

 merate beds in some places, as great masses of a grey colour, 

 with small red pebbles imbedded, were observed, belonging ap- 

 parently to this formation. As we descend to its lower beds, 

 moreover, the quantity of the slaty rock increases. From 

 these two circumstances, it may happen that the Trinity Bay 

 sandstone-formation may be identical with the rocks I shall 

 mention next. As, however, there is no direct evidence, except 

 mineral character, in favour of this supposition, and some cir- 

 cumstances seem to militate against it, I shall describe these 

 rocks separately. 



4. The Signal Hill Sandstone and Conglomerate, — This forma- 

 tion consists of a group of rocks generally of a dull red colour, 

 very hard and intractable, and thick-bedded. Its upper por- 

 tion is principally a coax'se-grained sandstone, frequently con- 

 taining beds of conglomerate of quartzose pebbles, some of 

 which are as large as a man's fist. In the lower part, the con- 

 glomerate rs generally smaller, and it is interstratified with 

 masses of a very fine grained gritstone of a very light grey co- 

 lour, hard and splintery, the beds of which are commonly very 

 thick, and in a limited section scarcely discernible. This grey 

 stone may be seen at Quidi Yidi, Signal Hill, and the base of 

 the South-side Hill of St John's. It is there used as building 

 stone, but, like the gritstone of the Bell Isle formation, its uti- 

 lity for that purpose chiefly depends on the direction of the 

 joints which traverse it, as it is difficult to trim it into shape. 

 From all parts of the formation large square blocks might be 

 frequently obtained fit for the construction of piers and break- 

 waters, or for similar purposes. The thickness of the formation, 

 or of that part of it exhibited near St John's, must be about 

 800 feet. 



5. The St Johns Slate-formation, — The gradation downwards 

 of the Signal Hill sandstones into this formation is perfect. 

 At their junction, beds of dull red and greenish fine-grained 

 gritstone alternate with each other^ passing upwards into a 

 coarser red sandstone, and downwards into a compact greenish 

 rook, that gradually acquires a slaty cleavage, and assumes 



