FILLMOBE COUNTY. 305 



Devonian limestones.] 



S. E. | sec. 20, Beaver. This rock is again seen here, exposed along the 

 banks of Beaver creek; owner's name unknown. It here shows a brachio- 

 pod resembling Orthis, and a radiating Fenestella. It is in the midst of an 

 uninhabited prairie, and only weathered pieces can be found. 



S.E. | sec. 18, Beaver. Several years ago a cellar, dug for a farmer's 

 residence, furnished stone of the same kind in sufficient quantity to con- 

 struct his house. Similar rock again appears in the road, N. W. J sec. 20. 

 Beaver, but is somewhat more vesicular. 



Widow Scarrie has a small quarry in a yellowish, fine-grained rock 

 almost non-fossiliferous, and probably of the Lower Devonian, on the S. E. \ 

 sec. 28, Bloomfield. Outwardly this much resembles the sandstone exposed 

 at Austin, in Mower county; but it has a doubtful brachiopod that appears 

 like Atrypa. Its weathered color, its homogeneity and fineness of grain, and 

 its irregularly rounded cavities containing loose, ochreous dirt, indicate it 

 to be the equivalent of that. It is with some doubt classed as Lower 

 Devonian. 



This limestone is found in loose pieces, and often in surface exposures, 

 on the tops of knolls near the state line, in sees. 33 and 34, York, the porous, 

 white Niagara appearing in the ravines. 



At a point two miles west of Granger the Devonian is fifteen or twenty 

 feet thick, in the top of the river bluffs. These thick beds give a square- 

 ness and prominence to the tops of the bluff's, presenting a perpendicular 

 rock-wall toward the river. Large masses of this rock fall from the bluffs 

 and weather into the usual rough forms. Though this exposure embraces 

 rock that is a little softer than the Devonian at Foreston, yet in color, 

 crystallization and all general characters it is the same. 



At the crossing of the south branch of Root river, N. E. sec. 21, Bloom- 

 field, there is no cut in the rock visible. The river is but about twenty feet 

 below the level of the country, which is in a broad shallow valley; but in 

 the road are a few pieces of rock showing fossils and lithology like the 

 Devonian at Spring Valley. The country here, and toward the southwest, 

 is a broad level prairie, gently rising toward the west. 



N. W. J sec. 26, Bloomfield. The south bank of the river, near the 

 west side of the section, has a rock bluff exposed about twenty feet above 

 the river. This is massive, or in heavy layers, and is doubtfully assigned 

 20 



