358 THE GEOLOGY OP MINNESOTA. 



[Devonian limestones. 



This appears but slightly at Le Roy, but is found along the Upper Iowa at 

 Chester, seven miles below Le Roy, and on Beaver creek in Fillmore coun- 

 ty.* It appears also in the northeastern part of the county, and in the 

 southwestern. Its original line of strike probably crossed the county 

 nearly east and west, through the central portion, and it is possible that 

 this rock reaches still as far north as Brownsdale, but it has been driven 

 southward by the erosive action of meteoric forces, particularly by the 

 "drift" forces, and by the action of the Cedar river, so that it now has a 

 flexure toward the south, even to the Iowa state line, along the Cedar val- 

 ley, and its area in the county is separated into two parts. As near as it 

 is possible to judge from the facts known, the strike of the lower beds of 

 this limestone is shown on the plate of Mower county. 



In the southwestern corner of the county, sec. 33, Lyle, are the quar- 

 ries of Mr. John Beech, one of which is on the south side of Woodbury 

 creek, east of the north and south road, and the other is on the river bank 

 about twenty rods south of the mouth of the creek. Here are seen about 

 eighteen feet of rough magnesian limestone beds, gradually dipping south 

 and entering the river before reaching the state line. They are the cause 

 of the water-power at Otranto, a few miles south, in Iowa, where flouring 

 mills have been erected. These beds are firm, but very rough and cavern- 

 ous, curly with concretionary structure and with rusty films that penetrate 

 them. The only fossils discovered are the impressions of a coarsely ribbed 

 Atrypa, having all the appearances of the so-called little: turtles, seen in a 

 similar rock at Spring Valley in Fillmore county. Indeed, the whole as- 

 pect of the rock is like that of the coarse rock containing those fossils. 

 This rock here overlies the Austin rock, though the actual overlie cannot 

 be seen. Its manner of approach to the river, and the topography toward 

 the south and west, taken in connection with its dip and the relation it 

 bears geographically to known outcrops of the Austin rock, are the only 

 evidences. The strike of this limestone from Beech's quarry northward 

 can be followed on the west side of the river by the terrace elevation which 

 they cause, running about a mile west of the river. Where this terrace is 

 crossed by Orchard creek, sec. 29, Austin, lime was burnt some years ago. 

 Toward the north further this terrace recedes from the river, apparently 



*See the Fillmore county report, p. 305. 



