6 4 
The Ohio Naturalist. 
[Vol. VII, No. 4, 
further emphasizes this distinction in his contribution (Glacial 
Phenomena of North America) to this volume. In defining 
these he says of osars or eskers: “These terms are restricted to the 
long, gravel ridges which conform, in general, to the direction of 
the ice-movement, and which are thought to represent the main 
drainage lines of the glaciers in their later stages, particularly 
when they approach a stagnant condition. The term kames, 
on the other hand, is applied to those gravel accumulations which 
take on the form of bunchy aggregations of knolls and irregular 
ridges, and have the tendency to arrange themselves in belts 
parallel to the margin of the ice. They frequently accompanv 
terminal morains and have a quasi-morainic aspect.” 
In his thorough work on “The Glacial Gravels of Maine,” 
under the head of “Sediments Transported bv Glacial Streams,” 
Stone ( 4 ) states that: “The simplest form is that of a cone, dome 
or hummock, and we find all transitions between these forms 
and the elongated, two sided ridges.” “These gravel deposits 
have such curious and distinctive shapes that they have received 
local names wherever they occur. The Scandinavian osars, the 
Irish eskers (or eskars or eschars) and the Scottish kames are 
supposed to be the equivalents of the gravel ridges here described, 
or nearly related to them. These deposits contain matter of 
various sizes fi'om fine clay to large bowlders, but gravel is by 
far the most abundant. I have found the term glacial gravel a 
convenient general title for describing every kind of coarse sed¬ 
imentary formation which was deposited by glacial streams. 
The term has the disadvantage of implying a theory as to the 
origin of these sediments, and it does not describe their compo¬ 
sition in all cases, yet it is often convenient as a generic name 
when there is doubt what specific name should be given to a cer¬ 
tain deposit, whether kame, osar, etc.” In chapter IV, “General 
Description of the Systems of Glacial Gravel,” the term osar is 
exclusively used for these systems. These are described as com¬ 
prising the sediments deposited by a single glacial river with its 
tributary and delta branches. Stone, in Chapter VI, quotes 
Chamberlin's distinction between the osar or esker on the one 
hand and kame on the other. He carries it a step further, how¬ 
ever, and applies esker to the separate mounds and ridges of a 
series of separated deposits known as a discontinuous osar. 
In his exhaustive works, “The Illinois Glacial Lobe” ( 5 ) and 
“ Glacial Formations and Drainage Features of the Erie and Ohio 
Basins,” ( 6 ) Leverett uses exclusively the term esker for these 
gravel ridges whose longitudinal axes correspond to the local 
axis of the ice sheet. Whether intentionally or otherwise this 
4. Monograph XXXIV. U. S. G. S. p. 34. 
5. Monograph XXXVIII. U. S. G. S., 1899. 
6. Monograph XLI. U. S. G. S., 1902. 
