THE SANTA FE ROUTE. 5 
On the bluffs of Kansas City there is a thin sheet of sand and 
gravelly clay, called till, which was left by the glacier or ice sheet 
that once covered this region. 
This occupation by ice was one of the 
most interesting events in the geologic history of the continent.! 
The new Union Station in Kansas City is in a marked depression or 
valley which lies behind the main bluff all the way from Missouri 
River on the east to the slopes descending to Kansas River on the 
west. 
This depression is now followed by most of the railways 
1In the earlier part of the glacial epoch, 
called the Kansan stage, the ice sheet 
extended from the north halfway across 
northeastern Kansas, reaching the present 
valley of Kansas River and in places ex- 
tending a few miles south of it. Probably 
the ice sheet had much to do with deter- 
mining the position of the Kansas River 
valley, for the river began at that time to 
flow in its present ttre course. This 
ice sheet covered about ,000 square 
miles in northern ant Asnerins about 
300,000 years ago and endured for a long 
time. It was several thousand feet thick, 
and it accumulated at a time when the 
fall of snow was in e 
with the advance of the ice, and appar- 
ently in some stages of its existence its 
margin remained at the same place for a 
long time. Its flow was due mainly to 
the thickness of the ice, for the land does 
not all slope downward to the south, 
which was the direction of the movement. 
The flow of a glacier of this character is 
illustrated in general by the lateral flow 
of a thick mass of pitch lying on a table. 
As the glacier moved along it picked 
up large quantities of rock and ‘oil. 
This material was slowly carried south- 
ward and in some areas accumulated at 
‘the southern edge of the ice in a deposit 
known as a terminal moraine. When 
melting gained on the rate of advance the 
covering the rocks of the country. This 
deposit is called till or drift. Much of 
the material was brought great distances, 
and its coarser components, iiiecially the 
bowlders, are of such character that their 
sources are known by geologists familiar 
with the rocks of the country to the north. 
Some of the bowlders that were carried 
moving rocks have cut in them. Man 
of the features indicative of glaciation 
are found in northe 
south as 
the surfaces of limestone ledges in the 
middle of the city. The scratches trend 
somewhat east of south and are clearly 
marked, having been preserved by a 
covering of the glacial till. This till caps 
the ridge in the northern half of the city 
but appears to thin out and disappear at 
no great distance to the south, indicating 
the southern limit of the ice. No clearly 
The till is all on the highland, indicating 
that the deep river valley now lying a 
short distance to the north did not exist 
in glacial time. 
Other glacial scratches are observed on 
the bluffs on the north side of the river 3 
miles north of Kansas City, about 100 feet 
above the river. One set trends S. 24° 
W. and another S. 51° E., indicating two 
directions of ice movement, Baits at 
two different advance. 
Scratches are also 
City, 
cut and extend for some distance, so that 
they could not have been produced by 
bowlders in floating or floe ice. 
