46 
Geology, 
north or south. Without therefore dwelling in detail upon the 
less unfamiliar features of the glaciers of the southern order, ^ 
we may pass to the special characteristics exhibited by the north- 
ern type, as shown by the glaciers in the environs of Inglefield 
Gulf. 
STRATIFICATION. The most impressive feature dis- 
played by these glaciers is the pronounced stratification of the 
ice. The stratification of glaciers is not at all new, but the re- 
markable extent, definiteness and peculiar characteristics of the 
stratification displayed in the vertical walls of these northern 
glaciers amounts practically to a revelation. The ice is almost 
as distinctly bedded as sedimentary rock. On the vertical face 
there are usually presented two notable divisions, an upper one 
of nearly white ice, whose laminations are not conspicuous from 
lack of differential coloration, and a lower one discolored by 
debris, which gives great distinctness to the bedded structure. 
The lower division is divided by very numerous partings, along 
which are distributed rocky debris, embracing not only sand and 
silt, but rubble and bowlders. Often the amount of this inter- 
spread debris is so slight as to constitute the merest film, while 
at other times it reaches a thickness of an inch or two, and some- 
times it is distributed throughout several feet. In the last case, 
there is usually an intermixture of rock, rubbish and ice, but, 
in general, the rocky debris is arranged in very definite and 
limited horizons, leaving the ice above and below as clean and 
pure as any other. It is very notable and significant that the ice 
next the debris layers is the firmest and most perfect ice which 
the glacier affords. It fractures in a peculiarly vitreous fashion, 
and sends forth beautiful iridescent reflections from between the 
fracture faces. The coarser debris is arranged in the same hori- 
zons with the fine silt and clay. Often fragments several times 
as thick as the average silt layer will be centered upon it, pro- 
jecting upwards and downwards into the ice on either hand. 
Where the ice is well laminated, as it very commonly is, the lam- 
inations bend under and over the embedded bowlders, just as 
5. These have been given in the Journal of Geiology, November-De- 
cember, 1894, pp. 768-788. 
