322 GEOLOGY OF OHIO. 



feet below this, in the bed of a stream, alternate layers of argillaceous 

 and sandy shales are exposed. 



The top of the quarry east from Mansfield is twenty feet below the top 

 of this coarse sand-rock, and is a continuation of it, the town resting 

 upon this formation, which crops out on all sides of it. About sixty feet 

 of the rock is here exposed. It is all much broken; the upper thirty 

 feet in thin layers, the lower thirty feet in layers of from one to six feet 

 thick. Much of the rock is beautifully colored in waved bands and lines 

 of black, yellow, and red, as delicately shaded as the best artificial grain- 

 ing of wood. Very beautiful specimens can be obtained, and if it were 

 harder it would make a very ornamental building stone. It dresses 

 smoothly and endures exposure well, but is soft and easily worn away by 

 abrasion. 



On Brushy Fork, near Millsborough, about six miles west of Mansfield, 

 and thirty-five feet above the Mansfield quarry, is the outcrop of the same 

 rock, of which the following is a section : 



FT. 



1. Coarse, shaly sandstone in broken layers 12 



2. Ferruginous sandstone, ■with waved lines of stratification 6 to 10 



8. Coarse, massive sandstone, witli irregular veins of iron 6 



4. Shelly sandstene 8 



5. Blue argillaceous shale, with bands of hard, fine-grained sandstone to 



bottom of exposure. 



The upper numbers are the thinning out of the Mansfield rock, the 

 equivalent of the Waverly Conglomerate. 



On the opposite side of the stream, the yellow sand-rock on Ne.wton 

 Gilkinson's land is about thirty-five feet thick, coarse, ferrugingus, with 

 black iron streaks. There are about ten inches of light-colored and firm 

 stone. All the rest, so far as exposed, is worthless for building purposes. 



The rock at bottom is blue argillaceous shale, with hard blue bands, 

 bearing a o4ose resemblance to the Erie shales; no fossils discovered. In 

 places, interstratified between the layers of the yellow sandstone, there 

 is a layer of ten to twelve inches of white argillaceous shale, which, when 

 disintegrated, bears a close resemblance to the fire-clays of the Coal \feas- 

 sures. Outcrops of this rock are to be seen northward, near Lexington, 

 and between Lexington and Bellville, containing quartz pebbles and 

 many nodules of soft iron ore ; all the rock, in thin layers, extending to 

 the tops of the hills, making the connection complete between the Mans- 

 field and Bellville quarries. The Clear Fork here flows through a broad 

 -alluvial valley, bordered with heavy hills of modified Drift, generally 

 . sandy, in places composed of coarse, water-worn pebbles and bowlders, 



