Sqwer—Peculiar Deposits on the Mississippi Bluffs. 259 
The topographic sheets of the lead region show that few of 
the valleys exceed 150 feet deep in a cross section, although the 
extreme range between the highest parts of the divide and the 
valley bottoms is somewhat greater. 
In the central area the valleys show depths of 400', 450', per¬ 
haps in places even 500' on a width between summits of 2,000' 
to 8,000'. 
This disparity in depth would be still further increased did 
the comparison extend to the ruck doors. The deposits on 
the valley bottom being rather shallow in the lead region. 2 
The average for the central area as a whole I have no means 
of estimating, but for the east—west belt which includes the 
La Crosse and Lemonweir valleys I think it will exceed 
100', and that in places it will nearly reach 300'. 
The disproportionate depth of the valley floors in the two 
regions is somewhat suggestive of crustal warping. 
Of the three areas, the lead region has received by far the 
most study; the central, I think, the least. 
Nearly half a century ago J. D. Whitney * 1 described a group 
of sandstone blocks which were about 125' above their proper 
horizon. 
A few years later Moses Strong 2 described two other occur¬ 
rences of a similar character of which one was three, the 
other five miles from the nearest outcrop of the St. Peter 
sandstone. 
More recently F. W. Sardeson 3 has described certain accum¬ 
ulations of clay, chert and sandstone blocks in the Pecatonica 
Valley having a somewhat morainic aspect. 
Although I have never visited the lead region I should like 
to call attention to one aspect of the case which shows at the 
same time the extent of the glaciation problem as presented in 
the lead region and the great difference between the problem 
as there presented and as presented in the central region. 
2 Chamberlin and Salisbury give 18.17' as the average of fifty-five 
measurements. Sixth Annual Report U. S. Geological Survey p. 250, 
1885. 
1 Geology of Wisconsin Vol. 1, P. 137, 1861. 
2 Geology of Wisconsin, Vol. 2, P. 667, 1877. 
s American Geologist, Vol. 20, P. 392, Deo., 1897. 
