[amr] GEOLOGY OF SOME CITIES IN EASTERN CANADA 133 
some of the blocks having been used in the construction of the Sou- 
langes canal. 
The Trenton formation—The Trenton formation consists for the 
most part of evenly bedded, bluish-gray, impure, limestones, somewhat 
bituminous, at times, cherty, occasionally separated by thin shales. 
It is highly fossiliferous throughout and its thickness ranges some- 
where between 400 and 500 feet. It was from these limestones that the 
late Elkanah Billings obtained, while he was a resident of Ottawa, the 
great bulk of those remarkable species of Crinoidea, Cystoidea, and 
Asteroidea, which he described so carefully and gave him as well as this 
locality a great reputation and a name. 
The Trenton is probably the most conspicuous formation in and 
about Ottawa. The bluff upon which the Parliament Buildings are 
situated, Nepean Point, and the cliff shores of the.Ottawa from the 
Chaudiére Falls down to Rockcliff Bay, as well as the numerous quarries 
and outcrops of limestones along the river Ottawa, and Brewery Creek 
at Hull, form the most conspicuous outcrops known. Besides these, 
excellent exposures of this formation may be seen at Robillard’s 
quarries, the Rockland quarries, the C. A. R. cuttings near Division 
street, and east of the Experimental Farm. It is needless here to give 
a detailed account of the fossil remains entombed in this interesting 
formation. Not less than 250 species have already been obtained of 
its abundant fauna and flora. Only the more characteristic forms, such 
as would readily be met with by any collector will be incorporated in the 
synoptical table. For a more extended list of the characteristic species 
of this formation, the reader is referred to the paper cited above, 
pp. 154-166. 
The limestones of this formation afford excellent building stone. 
Certain “gray bands” of semi-crystalline limestone, which occur in the 
lewer half of the Trenton, supply the best material for construction and 
decorative purposes, and have been employed in some of the finest resi- 
dential and public buildings of the Capital. The Trenton also furnishes 
excellent rock for the manufacture of calcium carbide and lime. 
The Utica formation.—The upper measures of the Trenton forma- 
tion pass imperceptibly into the shaly and calcareous measures of the 
Utica. The transition is quite gradual, but the bituminous character 
of the latter soon become a prominent feature as we ascend in the series 
of sediments of the stratigraphical column at Ottawa. The. Utica consists 
for the most part of black or dark brown, brittle bituminous shales 
which attain a thickness of from sixty to seventy-five feet. Its marine 
fauna at the base is not unlike the fauna of the shaly bands of the upper 
Trenton. In contrast with this, the middle and upper Utica measures 
