208 Account of the Rocks in the Neighbourhood 



rent or chasm by whicli the river formerly emptied itself into 

 the sea, may have been gradually enlarged, till it has attained 

 its present size. The average width may be two or three hun- 

 dred yards. Quidi ^'^idi (pronounced Kitty-vitty) river and 

 lake may one day present an entrance and harbour similar to 

 those of St. John's. 



The mineralogy of the country round St. John's is very sim- 

 ple. The first rock, on entering the Narrows, is trap-tuff. 

 This rock is distmctly stratified, each stratum generally m»ea- 

 suring two or three feet in thickn.ess. The strata lie NE. and 

 SW., or rather NE. by N. and SW. by S. The dip is to the 

 NW., at an angle of from 70" to 80^ The basis of this rock 

 consists chiefly of distinct grains of quartz, felspar, and a red 

 claystone. The imbedded minerals or pebbles are, for the 

 most part, of the same substances ; felspar, common and com- 

 pact, the latter widi small imbedded grains of quartz ; quartz, 

 often of a slaty or fibrous structure; jasper, z'ed claystone, 

 bloodstone, hornstone, &c. These imbedded minerals, at the 

 foot of the hill or cliff (particularly the quartz and felspar), are 

 o-enerally from an inch to three inches in diameter, and gra- 

 dually decrease as we ascend ; at the top of the hill, they rarely 

 exceed the fourth part of an inch in diameter. Does not tliis 

 fact countenance the mechanical deposition of the trap-tuff? 

 This rock appears much harder than the common varieties of 

 the trap-tuff which I have seen. 



It is this rock which forms those precipitous cliffs on either 

 side of the mouth of the Narrows. The opposite sides of the 

 Narrows rise very rapidly from the sea to a considerable height. 

 The highest part of the trap-tuff formation is about 300 feet 

 above the sea ; its thickness about 500 yards. The trap-tuff 

 passes very gradually, and most beautifully, into the next rock, 

 which is amygdaloid. In this passage of the one rock into the 

 other, the stratified structure is still retained, one stripe or 

 narrow stratum being distinctly marked trap-tuff, the next 

 amygdaloid ; the stripes of the former being broadest at first, 

 gradually becoming narrower and less defined, till the amyg- 

 daloidal rock entirely prevails. 



The strata of the amygdaloid also run in the direction of 

 NE. by N. and SW. by S., and dip likewise to the NW. at an 

 angle of about 65^. The basis of this I'ock, like that of the 

 trap-tuff, consists of minute grains of quartz, felspar, and clay- 

 stone. The imbedded portions are invariably of a red, smooth, 

 hard claystone : they seldom have the amygdaloidal form, but 

 are square, or rhomboidal, or in longish slates. The greater 

 part of the amygdaloidal rock is entirely destitute of these 



portions, 



