AVALON TERRANE 219 



age.* Subsequently he restricted the name to the gneissic series f and. 

 did not consider the upper series. X 



The name Avalon is now proposed on account of the typical develop- 

 ment of the^terrane on the peninsula of Avalon. It includes four prin- 

 cipal formations, § designated as follows : 



Thickness 

 in feet 



Signal Hill 3,120 



Momable 2,000 



Torbaj- 3,300 



Conception 2,950 



11,370 



Signal Hill sandstone. — The typical localities are at Signal hill, Saint 

 Johns harbor, Bay de Verde, New Perlican, and Baccalieu island. 



Feet 



1. Red conglomerate, the pebbles of which are chiefly white quartz, but with 



occasional pebbles of brown or red jasper, syenite, or gneiss and slate ; 



the pebbles vary in size from a pea to a 6-pound cannon ball 500 



2. Dark red sandstone, hard and tough, in strong, massive, irregular beds, 



from 2 to 3 feet thick, passing into a fine conglomerate at the top ; the 

 whole reticulated with veins of white quartz 1,320 



3. Greenish or gray fine grained sandstone, very hard, with conchoidal frac- 



ture; difficult to work, but used to a large extent as a building stone, 



in beds varying from 1 to 3 feet thick 1,300 



Momahle slates. — This series of slates is cut across by Momable bay, 

 and is well shown at Saint Johns, Harbor Grace, Carbonear bay, Roberts 

 bay and Northern bay. 



Feet 

 Dark brown or blackish slates of Saint Johns, with ripple mark very dis- 

 tinctly displayed upon some surfaces, and in w^hich some obscure organic 

 remains have been found resembling the fossils found in the Torbay forma- 

 tion, and another supposed to be the shelly casing of some description of 

 Annelid (Arenicolites) ; the cleavage of this slate is sometimes very reg- 

 ular, oblique or at right angles to the bedding, but in parts it also cleaves 

 parallel with the stratification ; toward the top there are frequent layers 

 of hard, fine grained, greenish sandstone interstratified, not usually more 

 than 6 or 7 inches in thickness 2,000 



Torbay slates. — At Torbay this series is finely shown. It covers a great 

 extent of countr}' in its broad extension from cape Saint Francis to cape 

 Race, Saint Marys bay, and across to Conception bay. 



* Am. Jour. Sci., 3d ser., vol. 1, 1870, p. 87. 



t Chem. and Geol. Essays, 1875, p. 194. 



X Ibid., p. 244. 



I Geol. Survey Newfoundland, Reprint of Reports, 1881, pp. 145, 146. The distribution of the 

 various formations is finely shown on the geological map of the peninsula of Avalon, Murray & 

 Howley, 1881. 



