Age of the Kansaii Drift Sheet — Hershey. 25 
river, of remnants of the Lafayette formation under the drift. 
If the identification prove correct, the Kansan drift will thus 
be demonstrated to be newer than the Lafayette formation. 
True, it has by many glacialists been so considered for years, 
but it is hardly proven. The evidence drawn from the valleys as 
given above is as yet the strongest which can be adduced. 
]\Iy present impression is that between the close of the 
Lafayette epoch and opening of the Kansan glaciation of the 
Missouri region, the cafion valleys of southei"n Missouri had 
been eroded to nearly their present size and that while the 
great post-Kansan denudation was being accomplished on the 
drift plain at the north, erosion south of the Missouri river was 
confined chiefly to a widening of the cafion valleys which, 
while relatively small as measured in material removed, was 
yet large as measured in time occupied. 
In conclusion, I submit the proposition that \\hile the Kan- 
san epoch is probably post-Tertiary in taxonomic position, re- 
cent erosion studies on the Kansan drift areas cut sadly into 
that supposed long preglacial portion of the Quaternary era 
designated the "Ozarkian sub-period" and when the still earlier 
drift sheets have been correctly placed in the time scale, there 
may be little left of it. 
Berkeley, Cal, Feb. 2, ipoi. 
THE GEORGIA BAUXITE DEPOSITS; THEIR 
CHEMICAL CONSTITUTION AND GENESIS." 
By Thomas Leonard Watson, Geol. Survey of Georgia, Atlanta. 
PLATE VII. 
Iiitroduetiou: As the heading implies, the object of this 
paper is to explain the chemical constitution and genesis of the 
bauxite deposits of the Coosa valley region of Georgia and 
Alabama. The discovery of bauxite in i887,f a few miles 
northeast of Rome in Floyd county, Georgia, was the first ac- 
count of this mineral found in the United States. The first 
shipments of the ore were made in 1888, and. the entire home 
consumption of bauxite in the United States has been, since 
1890, from the Coosa valley deposits in Georgia and Alabama. 
Although commercial deposits of the ore have been known in 
•Published by permission of the State Geologist. 
tNiCHOi.s, Kdwakd, An Aluminum Ore, Trims. Amer. Inst. Min. Eng., 
1887, vol. xvi, p. 10.5. 
