HAWORTH. | Physical Properties of the Tertiary. 255 
tains were now connected with them, and the debris likewise spread 
over their surface. 
From paleontologic evidence it seems that the northern part of 
the plains Tertiary, or that in the Dakotas and northern Nebraska, 
is older than the lowest Tertiary farther south in Kansas and the 
Indian Territory. Itis possibie that the explanation for such a con- 
dition is that just given. In this way the great corrasion of the 
surface of the Cretaceous in Kansas could have occurred during 
the time that the accumulations of the earlier Tertiary materials 
were forming in northern Nebraska and the Dakotas and possibly 
elsewhere in the mountainous areas. Near the beginning of the 
Neocene period changes were brought about in one way or another 
so that the drainage from the mountains spread sediments continu- 
ously from the Dakota-Nebraska area over the western part of Kan- 
sas and into the Indian Territory and farther south in Texas, reach- 
ing even almost as far as the Rio Grande. 
CHARACTER OF THE TERTIARY MATERIAL IN KANSAS. 
The Tertiary material in Kansas is composed of gravel,: sand, 
black sand, clay, and silt, with a small amount of material usually 
called “volcanic ash.” 
The Gravel—The gravel is pebbles varying in size from four or 
five inches in diameter to the finest of pebbles, grading into the sand. 
Their character is such that no doubt can be entertained regarding 
their former home. They are composed of granite, syanite, por- 
phyry, andesite, rhyolite, basalt, and not infrequently of pure quartz. 
In the granite pebbles the feldspars are generally of a reddish hue, 
but frequently the lighter colored ones seem to abound. 
It has been thought that the general character of the pebbles 
was different in different parts of the state; that those in the 
northern part differ materially from those in the south with inter- 
mediate grades between. During the two summers of active field 
work in the Tertiary areas of the west the writer has paid consider- 
able attention to this phase of the subject, and at the present can 
only say that thus far variations in character of the pebbles do not 
seem to be general, but only local, and probably accidental. He is 
not familiar with the crystalline rocks of the mountainous area in 
