196 The Ohio Journal of Science [Vol. XVII, No. 6, 



Half a mile west of the quarry, but on the northern side of 

 the Columbus pike, is a house below the level of the pike. A 

 lane leads past the eastern side of the house downward into the 

 ravine formed by Massie Creek. The house if about 1005 feet 

 above sea level, and rock occurs at about the same level along 

 the lane leading toward the creek. Here the following section 

 is shown, in descending order: 



Cedarville dolomite, massive 38 ft. 



Horizon about 967 feet above sea level. 

 Dolomitic limestone, breaking up into thin layers, and regarded as 



equivalent to the Springfield dolomite 13 ft. 



Dolomite, massive, showing bedding toward the top, regarded as 



equivalent to the Euphemia dolomite 7 ft., 6 in. 



The dip of the rock within this half mile, from the exposure 

 on Massie Creek to the quarry north of the railroad in Cedar- 

 ville, is not known, but is regarded as low. If this be true, 

 the level at which fossils become common in the quarry is about 

 36 to 40 feet above the base of the Cedarville dolomite, as identi- 

 fied along Massie Creek. Since the total thickness of Cedar- 

 ville dolomite exposed at the eastern Mills quarry, at Limestone 

 City, southwest of Springfield, is only 19 feet, the level at 

 which fossils become common in the Cedarville quarry appar- 

 ently is about 17 to 20 feet above the top of the highest part of 

 the Cedarville dolomite exposed at the eastern Mills quarry. 

 Since most of the fossils collected in the quarries southeast of 

 Springfield come from the lower, more massive and porous part 

 of the Cedarville dolomite, the level at which fossils become 

 more common in the Cedarville quarry may be estimated at 

 from 25 to 30 feet above the level of the top of the zone from 

 which most of the fossils collected southwest of Springfield have 

 been obtained. This difference in level between the richly 

 fossiliferous zone in the Cedarville quarry and that in the 

 quarries southeast of Springfield accounts readily for the dif- 

 ferences in faunal content noted. 



At the Mills Quarries, southwest of Springfield, the following 

 order of succession, in descending order, is noted: 



Cedarville dolomite: 



Porous rock 3 ft. 



Less porous rock 1 ft., 6 in. 



Thin bedded, fine grained rock 3 ft., 3 in. 



Massive, porous, richly fossiliferous rock 11 ft. 



Springfield dolomite, fine-grained, well bedded 10 ft. 



Transition rock, dense, but somewhat mottled 4 ft. 



Euphemia dolomite, porous 8 ft. 



