On the Geology of the Northwestern Regions of America. 329 
flows, is increased by the occurence among them of a Lignite- 
formation, covered in parts by deep beds of sand, capped by 
boulders and gravel. ‘The soft friable shales forming the bank of 
the river near its termination in the Arctic Sea are also strongly 
impregnated with alum. These aluminous shales cover a large 
portion of the delta of Mackenzie River, are continued along the 
banks of Peel’s River to the foot of the Rocky Mountains, and 
have been traced for a considerable distance along the coast, and ~ 
also along the shores of Great Bear Lake. ‘The aluminous 
shale is constantly associated with the bituminous formation, into 
which it often passes. 
~ The lignite-formation is stid more extensively developed ; and, 
as the occurrence of coal in any form in these high latitudes is a 
question of much interest, I shall here state briefly the results of 
it John Richardson’s observations and enquiries on the subject, 
to which he has given much attention. -* 
_ The Mackenzie traverses very obliquely the basin in which 
the lignite-formation is deposited, while Bear Lake River cuts it 
More directly across ; and it is at the junction of these two streams 
that the formation is best exposed. It there consists of a series of 
beds, the thickest of which exceeds three yards separated by layers 
of gravel and sand, alternating with a fine-grained friable sand- 
Stone, and sometimes with thick beds of clay, the interposing 
layers being often dark, from the dissemination of bituminous 
matter. “'The coal, when recently extracted from the bed,” says 
Sir John Richardson, ‘is massive, and most generally shows the 
Woody structure distinctly; the beds appearing to be composed 
of pretty large trunks of trees, lying horizontally, and having 
their woody fibres and layers much twisted and contorted, similar 
to the White Spruce now growing in exposed situations in the 
Same latitude. Specimens of this coal examined by Mr. Bower- 
ank were pronounced by him to be decidedly of coniferous 
origin, and the structnre of the wood to be more like that of Pinus 
than Araucaria; but on this latter point he was not certain. It 
'S probable that the examination of a greater variety of specimens 
would detect several kinds of wood in the coal, as a bed of fossil 
#€aves, connected with the formation, reveals the existence at the 
time of various dicotyledonous trees, probably Acerinee, end pee 
of Which appears to belong to the Yew tribe.” ..... “ Differ- 
ent beds, and even different parts of the same bed, when traced 
to the distance of a few hundred yards, present examples of 
‘fibrous brown coal,’ ‘earth-coal,’ ‘conchoidal brown coal,’ and 
“trapezoidal brown coal.’ Some beds have the external characters 
of @ compact bitumen; but they generally exhibit on the cross 
fracture concentric layers, although from their jet-like composition 
Stcoxp Sznts, Vol, XXI, No. 63, May, 1856. 42 
