I AMERICAN 



JOURNAL OF SCIENCE AND ARTS. 



[SECOND SERIES.] 



Art. XXY.—On the Saliferoiis Rods and Salt Springs of Michi- 

 gan; bj Alexander Wixchell. 



The perfectly dish-shaped conformation of the strata of the 

 lower peninsula of Michigan, has prevented the escape to the sea 

 01 such soluble substances as were originally embraced in the 

 niarine deposits from which the rocks were formed. Were there 

 ?ny point in the margin of one of these rocky basins, lower than 

 Its central portions, chance for escape of all its soluble contents 

 J'OQld have existed ; and it is doubtful whether in such case, 

 onnes could have been retained to the present day, in any con- 

 siderable quantity. Our subterranean peninsular basms are 

 comparable with the superficial basins in which the salt lakes of 

 the world are located. Neither class of basins has an outlet, 

 /ne basin of lake Superior was once filled with water as salt as 

 that of the Great Salt lake. Both have received accessions 

 of freshwater; but while one has been drained by an efflux 

 ^ich has continually carried awav some portions of the chlond 

 2,\ sodium, the other has been drained only by evaporation. 

 ^Qf sahneness of one has been reduced almost to an mfinitesi- 

 ^^ quantity ;* that of the other is unimpaired, if it has not 



