340 GEOLOGY OF OHIO. 



magnesian limestone, like the Onondaga. The outcrop here causes a 

 little rapid in the river, although the beds are not bare except where 

 quarried, the water coming in contact with bowlders only. The most 

 common fossils are Favosites, Acervularia, Coenoslroma, and Cyathophyl- 

 loids. There is also occasionally a distinct crinoidal structure. Some of 

 the corals are blackened, and smell of petroleum. Oil also gathers on 

 the surface of standing pools of water about the quarry. 



The Onondaga Limestone.— This is the lowest member of the Corniferous 

 group in Ohio. It outcrops further up the Auglaize than the last described, 

 and is burned for lime by Frank McEvoy, S. E. J sec. 5, in Brown town- 

 ship. The beds here are thinner than where exposed at a lower horizon. 

 These heavier magnesian beds are quarried, in connection with the 

 Oriskany, at Charloe, including also some of the upper layers of the 

 Waterlime. The river here is thrown into a long series of rapids in 

 passing these more persistent beds. This quarry is south of the mouth 

 of Blue Creek, on the west side of the Auglaize, and shows, according to 

 the statement of the proprietors, the following thickness for the several 



members : 



Section at Charloe. 



No. 1. Sandstone, having the appearance of that at Grand Kapids, 

 in Wood county; hard; sawn off for flagging; suture- 

 jointed upon No. 2 ; seen, only gin, 



" 2. Even-grained magnesian limestone, of a buff color, contain- 

 ing nodules of chert ; sawn into handsome building 

 blocks, and exported largely 4 ft. 



" 3. Dark drab ; soft ; magnesian ; with some cavities which of- 

 ten contain straw-colored calcite 1 " 10 " 



" 4. Rough ; blue-drab ; close-grained ; heavy and hard, or brec- 

 ciated and vesicular ; with some pyrites ; in one bed, of 

 at least , 3 " g « 



Total seen 9 " io " 



Of this section, No. 1 is the base of the Oriskany; No. 2 is a stone 

 seen at other places embraced within the Onondaga limestone ■ Nos. 3 

 and 4 are the uppermost members of the Waterlime. (See Geology of 

 Wood County.) 



The Oriskany Sandstone. — In north-western Ohio the beds supposed to 

 represent the Oriskany of New York play an important economical part 

 in the geology of that district. They do not exceed an aggregate thick- 

 ness of twenty feet, and are sometimes less than ten ; but from the quar- 

 ries that have been opened in them in different counties they have sup- 

 plied stone for the most important structures. The horizon at which' 

 the sandy phase appears exhibits some variation, as has been mentioned 

 in reports on Wood and Sandusky counties. The arenaceous character 



