PEALB.J 
NORTHERN CENTRAL STATES. 
129 
NORTHERN CENTRAL STATES. 
The broad areas of Carboniferous rocks with underlying- Devonian 
and Silurian strata that are spread over so large a portion of the 
Northern Central States would lead us to look in this section for min- 
eral springs similar to those found along the western side of the Appa- 
lachians in the Atlantic States and in the northern i>ortion f the 
Southern Central Division. Here, as in those sections, chalybeate, 
saline, and sulphureted springs predominate. Calcic springs are 
more numerous than in the other sections, while thermal springs are 
inconspicuous, such waters as are referable to this class being derived 
almost entirely from artesian borings. 
As we proceed toward the northern part of the section and reach the 
metamorphic areas, the springs become more like those of the New 
England States. 
The waters used commercially are second in number only to those 
so used in the Northern Atlantic States. A fair proportion of the local- 
ities are resorts, and we may expect the number so used to increase 
when the newer parts of the Northwestern and Western States are 
more thickly populated. Every year adds to the number of improved 
springs in these portions of the Northern Central States. Nebraska, 
at present, is the only State in the section for which we are unable to 
give a supposably complete list of mineral springs. 
Summary for NortJiern Central States. 
States. 
lObio 
Indiana 
Illinois . . . 
Michigan .. 
Wisconsin 
Minnesota 
Dakota . . . 
Iowa 
Missouri. . 
Nebraska . 
Number of 
spring lo- 
calities. 
Number of 
individual 
springs. 
Number of 
springs 
analyzed. 
Number of 
spring lo- 
calities 
used as 
resorts. 
Number 
used com- 
mercially. 
Total num- 
ber of an- 
alyses. 
101 
52 
44 
75 
27 
23 
32 
133 
3 
31 
106 
151 
91 
76 
146 
441 
3 
129 
Total 
601 
1,276 
215 
122 
55 
224 
Bull. 32- 
(257) 
