516 APPENDIX. [No. I. 



ping both to the east and west. Below this, there is a peaty bog whose 

 crevices are filled with petroleum. 



This mineral exists in great abundance in this district. We never observed 

 it flowing from the limestone, but always above it, and generally agglutinating 

 the beds of sand into a kind of pitchy sandstone. Sometimes fragments of 

 this stone contain so much petroleum as to float down the stream. The lime- 

 stone dips under the water and disappears at Pierre au Calumet* and the 

 pitchy sandstone cliffs which rest on it also terminate there. This spot, 

 situated between three or four miles below an old fort, obtains its name from 

 a bed of yellowish-grey compact marl, which forms a small cliff on the bank 

 of the river, and is quarried by the voyagers for the purpose of making 

 calumets or pipes. A portion of this bed, acted on by the weather and the 

 water of the river, is converted into earthy marl, and is much used by the 

 traders under the name of white earth for whitewashing their apartments. 

 Immediately under the marl, and generally covered by the river, there is a bed 

 of limestone almost entirely composed of orthoceratites and bivalve shells*. 



For some distance below Pierre au Calumet to a place called Burnt Point ? 

 the banks of the river rise in a gentle swell until they attain the height of 300 

 feet at a short distance from the shore. They appeared to consist of sand 

 with limestone boulders, but we saw few sections of them. Between Burnt 

 Point and Athabasca Lake, the banks are every where low and alluvial, con- 

 taining much vegetable matter, and overgrown with willows and aspens. 



In Athabasca Lake we again came upon the edge of the primitive forma- 

 tion. The country around Fort Chipewyan is composed of roundish masses 

 of naked rock, which heaped, as it were, on each other, and rising as they 

 recede from the lake, attain, at the distance of a mile from the shore, an 

 elevation of five or six hundred feet. The valleys are narrow, their sides often 

 precipitous, and the general form of the hills may be termed short conical, but 

 their outline is very uneven. The rocks also form many islands in the lake from 

 two to three hundred feet high, and generally bounded on one or more sides by 

 precipices. The Fort seems to stand upon a granite rock. A little to the 

 eastward, a reddish granite is associated with grey gneiss. The strata much 

 convoluted and intersected in various directions by veins filled with a bluish 



* This orthoceratitic limestone bears some resemblance to the mountain limestone of mineralogists. 

 It may therefore possibly belong to the formation under the new red sandstone. 



