356 Geological Survey of the State of Ohio. 



On this limestone is imposed a yellowish siliceous limestone. 

 It is generally destitute of organic remains. It is quarried exten- 

 sively for building, and is burned for quick-lime. 



II. This consists of a bed of shale, two or three hundred feet 

 in thickness. It is generally black, very fissile, and frequently, 

 when breathed upon, exhales a fetid odor. Towards the lower 

 part of this deposit, occur masses of carbonate of lime, of a Sfhe- 

 roidal structure. Some of them are globes, and on being broken, 

 exhibit no peculiar structure. Others appear to have been origi- 

 nally amorphous masses, traversed by calc spar and sulphate of 

 baryta, and constitute the nuclei around which concentric layers 

 have subsequently formed. Others, again, are lamellar in their 

 structure. Sulphate of alumine and potash and sulphate of iron 

 are abundant throughout this deposit. From these materials cop- 

 peras might be manufactured in large quantities. 



III. Waverly Sandstone Series. — This name has been applied 

 to a fine-grained sandstone which is extensively quarried at Rock- 

 ville, Portsmouth, Piketon, and Waverly. It constitutes the best 

 building material in the State. This group consists of alternating 

 layers of shale and sandstone, varying in thickness from a few 

 inches to two or three feet. Some of this sandstone contains a 

 large portion of aluminous matter, so that it readily exfoliates on 

 exposure to the air. The most common organic remains in this de- 

 posit are Encrini, (a species oi Helix ?) besides some bivalve shells. 

 The moulds of these remains are often filled by sulphuret of zinc 

 and sulphate of strontian, but more frequently by sandstone. We 

 have also noticed one or two species of Fucoides, probably non- 

 descripts. Throughout the whole extent of this formation, from 

 the Ohio river to the lake, ripple marks are found. Some of them 

 are so surprisingly regular as to resemble the flutings of a Corin- 

 th ian pillar. We have seen a surface of a hundred feet in length 

 by fifty broad, marked in this way. 



IV. Conglomerate. — This rock sometimes consists of an aggre- 

 gation of quartzose pebbles, and again passes into a granular sand- 

 stone. It crops out on the western border of the coal measures 

 in bold escarpments, varying from 80 to 100 feet in thickness. In 

 a rock composed of such materials, we should not look for homo- 

 gcniety of character or uniformity of thickness : for in the detri- 

 tus, brought down from the primitive mountains, — of which the 

 secondary rocks appear to have been formed, — the pebbles would 



