THE GEOLOGY OF MINNESOTA. 



[Dolomitic limestones 



The Kasota stone is shipped to nearly all parts of Minnesota, to Sioux 

 City and Le Mars in Iowa, to various places in Wisconsin and Dakota, as 

 well as to Chicago and Winnipeg. It may be seen in the trimmings of the 

 market house in St. Paul, and of the dry goods house of Auerbach, Finch & 

 Co. At the same place the Baptist church is constructed of it (plate F). 

 Much of the state lunatic asylum at St. Peter was built of it. The trim- 

 mings of Christ church, Minneapolis, and of the Plymouth church, are of 

 the Kasota stone; also of the Drake and the Odd Fellows' blocks at St. Paul, 

 and of Williams hall, one of the buildings of Carleton college. 



The colored rock which is faintly stained with iron (No. 23) is that 

 which is most highly prized at these quarries, on account of its peculiar 

 color, but it appears from the tests of these stones made by the survey, that 

 the unstained stone (No. 19) from the same quarry, though not varying 

 much in chemical composition from the other, ranks higher in the scale 

 than the fawn-colored stone. It resists a greater crushing weight, but 

 withstands the action of frost and water and of corroding vapors, and of a 

 moist atmosphere, less successfully than the fawn-colored stone. 



At Mankato the principal quarries are owned by Geo. Maxfield, J. E. 

 Beatty, the Winona and St. Peter railroad company and by J. R. Beatty 

 and Co. That of Maxfield was begun in 1853; that of Mr. Beatty in 1854. 

 The product of these quarries is quite extensive, most of the stone being 

 used along the line of the Winona and St. Peter railroad. The texture of 

 the stone here is about the same as that at Kasota, but less of it has the 

 peculiar color of the Kasota stone. It is in horizontal heavy strata varying 

 from a few inches to over two feet in thickness. Near the bottom of the 

 quarry most wrought there is a change of color to a light blue. This 

 appears first in the center of the strata, but gradually increases so as to 

 involve the whole rock. This seems to indicate that the original color of 

 the whole formation was blue, and that it has lost it to a great depth (gen- 

 erally below the depth of all quarries) by exposure to the air, assuming the 

 prevalent buff color. The stone here is used for all purposes of construction, 

 and for flagging. Some ornamental cutting has been done (as at Kasota 

 also) for building and for tombstones. It is sent to the western and south- 

 ern parts of the state and to some points in Wisconsin and Iowa. It may 

 be seen in the trimmings of the public school-houses at Sioux Falls, Dakota, 



