GEOLOGICAL SCALE AND STRUCTURE. 29 



opinion of Prof. I. C. White, the Berea grit becomes the famous Murrys- 

 ville gas sand and also the Gantz oil sand of Washington county, Penn- 

 sylvania, but other of the geologists of the state and particularly J. F. 

 Carll, deny such equivalence. As a guide to the interpretation of our 

 series, and especially as a guide to our subterranean geology, it is 

 invaluable. 



The stratum was named by Newberry from the village of Berea, 

 Cuyahoga county, where the largest and most important quarries of the 

 formation are located. The name is the most appropriate that could 

 have been selected for this stratum, and inasmuch as it has priority in 

 all fields, it ought to be made to supersede all other names, in adjoining 

 states as well as in Ohio. 



From what has been already stated, it will be seen that the Berea 

 grit and the Waverly quarry-stone of southern Ohio are one and the same 

 sheet of sandstone. The identity was missed for a long while in the 

 study of our geology and a wrong order of arrangement found temporary 

 acceptance. The resulting dislocation of our Sub-carboniferous series 

 brought into all our work upon it an element of confusion that is scarcely 

 yet eliminated. 



The Berea grit, as seen in outcrop, is a sandstone of medium grain 

 in northern Ohio and of fine grain from the center of the state southwards. 

 In northern Ohio it contains one pebbly horizon over a considerable 

 area, but the seam is thin and the pebbles are small. The stratum is 

 sometimes false-bedded and on the other hand, it is sometimes remark- 

 ably even in its bedding-planes. Its main beds or sheets have a maxi- 

 mum thickness of ten feet, but this is an unusual measure and is seldom 

 reached. The formation ranges in thickness from five to one hundred 

 and seventy feet. Occasionally, but very rarely, it fails altogether from 

 the sections in which it is due. I^ike the Bedford shale below it, it 

 stands for an old shore line, many of its surfaces being ripple-marked and 

 worm burrows abounding in its substance. 



It is poor in fossils, but not entirely destitute of them. Fish 

 remains are the most conspicuous, but by far the rarest of the forms it 

 contains. Plant impressions are also unusual through most of the for- 

 mation, but in northern Ohio there is a certain part of the stratum in 

 which they are quite abundant. They sometimes accumulate in quantity, 

 enough to be known as coal blossoms, the carbonaceous streaks that sep- 

 arate the sandstone beds varying in thickness from a line to a half inch. 

 These carbonaceous streaks are a source of weakness, as a rule, to the 

 stone. Throughout the great quarry district the material of which the 

 stratum is composed is sand as clean as can be found on any sea-beach 

 today. As the stratum is followed into central and especially into 

 southern Ohio it grows more impure as its sand grows finer in grain, a 

 small percentage of clay being held in it at most points. 



