S4 
THIRTEENTH REPORT. 
1 . 
Grams per 
liter. 
2. 
Grams per 
kilogram. 
Calcium sulphate 
.9936 
62 . 6636 
5 3542 
4.22 
Calcium chloride 
54.10 
Magnesium chloride 
14.97 
Magnesium bromide 
24.S400 
37 . 778S 
179.2391 
.7303 
2.37 
Potassium chloride 
22.16 
Sodium chloride 
158.17 
Silica 
Total solids 
311.5996 
255.95 
1. Brine from well of the Sand Beach Mineral Springs Co., Harbor Beach, Michigan. Analysis 
by S. P. Duffield. (Geol. Sur. of Mich., Vol. V, Part II, p. 82.) 
2. Brine from t lie Ryerson well, Muskegon, Michigan. Analysis by Dr. C. A. Goesmann, September, 
1883. (Geol. Sur. of Mich., report for 1901, p. 233.) 
The artificial brines, employed in the Ludington-Manistee and De- 
troit-St. Clair rivers districts, are formed by solution of the rock salt 
of the Salina formation. In the former the flow of ground water in i lie 
super-imposed strata is sufficient to form the brine and the pumping 
is done mostly with compressed air. At most of the plants in the 
southeastern part of the state, it is necessary to pump water into the 
wells and the brine when formed is forced up by water pressure. 
At Ludington and Manistee the salt layer has a thickness of 20 to 
30 feet and is found at a depth of about 1900 feet at Manistee and 
2,300 feet at Ludington. It has been thought that but one bed existed 
in this district, 1 However, the No. 4 well of the Anchor Salt Co. at 
Ludington shows the presence of four beds, respectively 20, 12, 7, and 
5 feet in thickness. The extent of this area is not known, but wells 
at Frankfort and Muskegon, which should have pierced it had it been 
present, failed to disclose any salt. 
The salt beds of the southeastern area are much greater both in num- 
ber and thickness, one being over 250 feet thick. In a general way they 
seem to dip away from the Cincinnati anticline and to increase in thick- 
ness along the dip. How far this increase continues we do not know, 
as no records are available beyond Royal Oak, where nine beds have 
an aggregate thickness of 609 feet. 
Another area in which rock salt has been found in considerable 
quantities, but has not, as yet, been exploited, is in the vicinity of Al- 
pena. Five beds of salt with streaks of anhydrite here show an aggre- 
gate thickness of over 300 feet. 
Although we have no positive evidence on the subject, from a considera- 
tion of the general geology of the state and the apparent increase in 
thickness of the beds along the dip, it seems reasonable to believe that 
these three areas are but portions of one larger area. Rock salt is 
therefore likely to be found anywhere within lines joining the outer 
limits of the different proved areas. 
The composition of the brines may be seen from the following- 
ail a lyses : 
'Lane, Report for 1908, p. 59. 
