162 THE GEOLOGY OF MINNESOTA. 



[Dolomites. 



territory, and has formerly been considerably used for bridges and other 

 construction on the line of the Winona and St. Peter railroad. It is seen 

 in the Congregational and Episcopal churches at Winona, and in the 

 county jail. The Congregational church at Winona is represented on 

 plate E. 



The most extensive quarry in this formation in the state is that of the 

 Chicago and Northwestern railway, near Stockton. This quarry was first 

 opened in 1876, in a systematic manner, though some stone had been taken 

 out at intervals before. The rock lies here, as in other quarries men- 

 tioned, in regular horizontal strata, from nine inches to twenty-five inches 

 in thickness, with rather more frequent and irregular joints than in the 

 quarries along the Mississippi. The texture, so far as the stone is used, is 

 homogeneous and fine, though somewhat vesicular. The beds, however, 

 are disturbed by porous and cherty masses which obliterate the stratifica- 

 tion, and are much more difficult to reduce to blocks suitable for transpor- 

 tation. This is only fit for rip-rap and filling, and is so employed largely. 

 The largest block ever shipped from this quarry contained sixty-eight cubic 

 feet. Some 300 men have employment about these quarries, and nearly 

 fifty more are engaged in dressing the stone for various bridges and build- 

 ings along the line of the railroad. The formation has a thickness of 162 

 feet, as measured, back of Stockton, on the road to Winona, but at the 

 quarries the thickness visible is only 145 feet. 



This formation is quarried about a mile east of Caledonia, in Houston 

 county, whence it has furnished the stone seen in several large buildings at 

 Caledonia, notably the German Catholic church and the county jail. The 

 latter is a fine building, the courses being about ten inches thick, rubble- 

 dressed, with trimmings of the same. At La Crescent the public school- 

 house was built of stone from the St. Lawrence, quarried in the bluff north 

 of the village. At Brownsville is a quarry in the same rock, which sup- 

 plied heavy stone for the railroad, and for other uses. 



The quarries at Lanesboro, in Fillmore county (Nos. 16 and 21), have 

 been used in the construction of several large buildings at Lanesboro. The 

 most of the rock is vesicular, often coarsely so, in which case it is used in 

 heavy blocks for the coarse masonry of bridge piers and foundations. When 

 finer-grained it can be cut into delicate forms. When dressed for window- 



