BUILDING STONES. 163 



Dolomitic limestones.] 



caps and sills the cut surfaces appear nearly white. The bedding varies in 

 thickness from two or three inches to two or three feet. Similar beds are 

 quarried at Whalen, in Fillmore county, and at Rushford. At Lanesboro 

 the Lanesboro hotel, the large flouring mill, the Presbyterian and the Cath- 

 olic churches and the public school, as well as a number of business blocks, 

 are constructed of this stone. 



The state capitol at St. Paul, erected in 1S82, is built wholly of Minne- 

 sota materials (plate D). The walls are made of red pressed-brick from Red 

 Wing. The trimmings of the windows and doors, the cornice and the water- 

 table, are of the dolomite of Frontenac (No. 13). At the grade line is one 

 course of ten inches of the brown sandrock from Fond du Lac (No. 34). 

 The foundation and all below the grade line, is of the blue dolomitic lime- 

 stone of the upper part of the Trenton quarried at St. Paul (see No. 22), and 

 from the grade-line to the water-table the walls are of the regular blue 

 limestone of the Trenton in broken ashler work (No. 28). 



4. DOLOMITIC LIMESTONES. 



As already remarked, the same formation which furnishes the dolo- 

 mites just described, also furnishes the most of those here grouped as 

 dolomitic limestones, and very often the two are found in the same quarry 

 in regularly alternating strata. The characters of these rocks, and their 

 manner of occurrence, have been described therefore, in some instances, in 

 giving the particulars concerning the dolomites. The two sorts do not pre- 

 sent such unlike physical characters, in some instances, as to require their 

 separation in construction, and they are then used undistinguishably in the 

 same building. This is particularly true of the quarries at Stillwater, Red 

 Wing, Frontenac, Winona, Stockton and Lanesboro, which are all in the 

 St. Lawrence formation. But the quarries at Shakopee, Kasota and Man- 

 kato, situated in- the lower portion of the Minnesota valley, are from 

 another and a higher formation (the Shakopee), though still embraced, in 

 general, in the same series of alternating sandstones and limestones, which 

 with some misapprehension of the stratigraphy, were placed by Dr. Owen 

 partly in the " Lower Magnesian," and partly in the Potsdam, and partly 

 denominated St. Peter. 



The rock of these last mentioned localities, however, is very similar 



