HawortH.| Physical Properties of the Tertiary. MTs) 
large quantities of sand from the river upon the dry land. 
There is a sentiment with the residents of the west that during 
the last fifteen years sands have traveled from the sandhills north- 
ward into the Arkansas river valley to a much greater extent than 
from the river channel outward upon the river valley. The filling 
up of the valley at the south end of the Cimarron bridge, as noticed 
in the discussion of the Arkansas river, is usually claimed by the 
citizens of that place to be largely due to sand traveling from the 
sand hills on the south. It is true, of course, that public senti- 
ment is often in error, but one may well suppose that during the 
last fifteen years those who are residing in the Arkansas river valley, 
and who are having their farms yearly increased or decreased in size, 
depending upon their location in the river valley, would make 
relatively accurate observations upon this subject. 
We have no means of determining the climatic conditions in pre- 
historic times. The sandhills on the south side of the river might 
be credited to northerly winds in prehistoric times were it not for the 
large gravel found in them frequently at the summit of the hills. 
But this would not account for the sand of other areas farther to 
the south, particularly those north of the Cimarron. Taking all in 
all it would seem that the explanations given include sufficient 
causes, each of which is in harmony with the results as ‘we can now 
observe them. ‘They are in brief, first, the unequal distribution of 
sand throughout the Tertiary materials at the time of deposition, 
and second, the separation of the finer material from the sand by 
water action and by wind action, leaving the sand behind after the 
finer material has been carried away. The particular shape of the 
sand dunes at the present time may be principally due to the action 
of wind, which has worn out cavities and built up hills and hillocks 
in such an iregular manner. 
SURFACE GRAVELS. 
Coarse gravel are found here and there over the surface through- 
out the Tertiary area of Kansas. Such formations are by no means 
as common or as extensive as the sand masses. In every instance 
noted they seem to be due entirely to the breaking down of mortar 
beds formations from which the gravel came to be scattered over 
