254 University of Kansas Geological Survey. 
detail. It is possible that if one were a careful study of the pebbles 
in Kansas might show a corresponding variation in character, so 
that an estimate could be made regarding this particular part of the 
mountainous area from which such pebbles were derived. But 
without such a knowledge of the crystalline rocks to the west it is 
doubtful if a discrimination between the character of the material 
in the pebbles found in the different parts of western Kansas will 
have any considerable value. Reddish feldspar is found along the 
northern border of the state, and in every county from the north 
line to the south. Dark colored material, which probably was 
horneblend or black mica, is associated with the feldspars in every 
part of the state. Quartz grains also are intimately associated with 
the feldspars throughout the whole area. Occasional pebbles of 
basic rock are likewise found promiscuously scattered from the 
north line of the state to the south. Free quartz, or pebbles com- 
posed entirely of quartz, are found here and there lying in the sand 
and gravel beds beside the granite pebbles. 
At different periods of our investigation in the west it almost 
seemed that such a variation in the character of the gravel could 
be found. Doctor Adams, who has spent two summers in this 
country, reported in the autumn of 1895 that he was pretty well 
satisfied such a distinction between the character of the pebbles 
north of the Arkansas river and those south of it could be made, 
and might be of value. But the field work during the summer of 
1896 largely dispelled this idea. The individual gravel beds lying to 
the west and southwest of Meade in Meade county are composed 
essentially of the same gravel as those on the north bluffs of the 
Arkansas river, and of those much farther to the north, even almost 
all the way to the north side of the state. We may therefore dis- 
miss the idea that any one can discriminate between the character 
of the crystalline gravels in different parts of western Kansas, with- 
out a detailed knowledge of the crystalline rocks to the west so that 
a relatively obscure yet essential distinction might be noticed in the 
eravels corresponding to similar distinctions in the rocks of the 
Rocky mountains. Students of petrography will appreciate this 
point, for they well understand that such distinctions sometimes are 
important between different classes of rock, distinctions which are 
