of St. John's, Nelifoundland. 209 



portions, while, on the other hand, more than one-half of some of 

 the strata is composed of them. The amygdaloid is frequently 

 distinctly stratified, each stratmn being a lew feet thick. 



The trap-tuff and amygdaloid are both of a reddisli colour; 

 the latter, however, sometimes occurs of a grey colour. 'I'he 

 greatest height of the amj-gdaloid formation is 500 feet * ; its 

 thickness is about three or tour hundred yards, extending from 

 the top of Signal Hill to the foot of the Crow's Nest. 



Resting upon the amygdaloid is found the greenstone, lower 

 in height than the amygdaloid, but higher than the trap-tuiF. 

 This rock extends from the foot of the Crow's Nest (it being 

 of greenstone) to the foot of the Signal Hill, or to the town of 

 St. John's, a thickness of six or seven hundred yards, The 

 Crow's Nest, on which is built a small fort, is lour hundred 

 feet above the level of the sea. The principal constituent 

 part of this rock is apparently felspar. Its most common co- 

 lour is green, though sometimes gray and red ; it is stratified, 

 and sometimes possesses a beautiful slaty structure. The 

 strata of the greenstone also run NE. and SW. ; their dip is 

 to the NW., at a much smaller angle than the preceding rock, 

 the inclination not exceeding 50". 



Resting upon the greenstone we find tlie next rock clay- 

 stone, the strata of which have the same dii'ection and dip as 

 the others, the angle of uiclination, however, not being above 

 35° or 40". The claystone formation extends two miles in 

 thickness beyond the greenstone, occasionally alternating with 

 strata of compact felspar, each stratum measuring from halt a 

 foot to a foot in thiclcness. The claystone being much softer 

 than the rocks before described, the country where it prevails 

 is also much lower. The town of St. John's is built upon the 

 claystone. In coloxn*, it is most frequently gray, often also 

 brown, dark-brown, led, whitish, and of other colours. It is 

 often l)eautil"ully striped. It is fine-gi'ained, smooth, and often 

 conchoidal in the fracture. The strata of this rock are occa- 

 sionally cohnnnar, which is also sometimes the case with the 

 greenstone ; and the columns are composed of round concen- 

 tric balls. 



The next rock, whose direction, dip, and inclination are the 

 same as those of the claystone, is compact felspar. This rock 

 first alternates with the claystone, and then prevails alone for 

 above a mile. Being harder than the claystone, the country 

 composed of it is higher. Its colour is also various, light and 

 dark gra}', greenish-gray, green, blue, &c. It is translucent, 

 or slightly translucent, on the edges, wliile the claystone is 



• Tiiij is the licif^lit oC Siixiial I (ill, llie liigliest \mvt of the foi luatioii. 

 Vol. GO. No. '2;)'J. Srpl. ia2'2. Dd perfectly 



