[amr] GEOLOGY OF SOME CITIES IN EASTERN CANADA 137 
on the Chelsea Hills and north of Ottawa, and spread to the south and 
carried along whatever loose materials or easily broken rocks could be 
detached, in their progress along and deposited them in the valley of the 
Ottawa which for the time being must have been filled with rock and 
ice as well as the country to the south of the river. The exact course 
of the different glaciers which proceeded from the different summits of 
the hills to the north of Ottawa, may be clearly seen in the beautifully 
striated and scored rock-surfaces in Hull and Ottawa. No fossil 
remains have as yet been discovered in the boulder clays of the Ottawa 
district. Whether the glaciers of the Ottawa district which travelled in 
a general north-west and south-easterly direction met the glaciers com- 
ing from the Adirondack massif at some intermediate point, and in 
what direction the ice travelled after such a conjunction are points still 
to be ascertained. 
The Champlain formation —This formation consists of marine clays 
and sands to which the designations Leda clay and Saxicava sand have 
been assigned and adopted by most geologists in Canada. Although 
these sands overlie the clay more or less uniformly throughout, 
there is little doubt that the two belong to precisely the same period, the 
sand however, being deposited immediately over the clay. While 
the continent was rising and the clays were being deposited in the deeper 
pertions of the gulf, the sand was being deposited at one and 
the same time along its shores. The clays consist for the most 
part of a stiff blue argillaceous mud with here and there sandy por- 
tions and occasional boulders present. In certain portions of the Ottawa 
district, these clays hold numerous calcareous concretions or nodules 
and have proved to be highly fossiliferous. Remains of seals, fishes, 
birds, insects, starfishes, sponges, and shells, of various kinds, abound 
in these clays and nodules. They have been made known to us more 
especially through the writings of Sir William Dawson, Prof. Penhallow, 
and other observers. The clays are often exposed in the shape of ter- 
races, or raised beaches at different elevations in the Ottawa Valley. 
They constitute the material from which the pottery and bricks are 
manufactured around Ottawa. The marine sands as well as the stratified 
sands of the present river channels derived from the decomposition and 
redistribution of the marine sands also afford material for construction. 
The Green’s Creek valley clays in the county of Russell and the 
shores of the Ottawa river at Besserers Springs, the clays north of 
Lake Deschenes above Aylmer, and on the Lièvre river near Bucking- 
ham, and other localities abound in fossil remains. The Saxicava sand 
formation with its characteristic fossil Saxicava rugosa has been ob- 
served at the Central Experimental Farm, near Hintonburg, in the 
