230 GEOLOGY OF OHIO. 
textured, often carious, yet when compact is crystalline. It is in thin 
beds of about three inches, more or less lenticular, making it easy to 
quarry and to get into fragments of suitable size. Yet it also sometimes 
has a brecciated or concretionary structure, when large pieces of irregu- 
lar shape, often cavernous and easily broken, are taken out. It has a 
light buff color, and is sometimes white. When freshly quarried it may 
be spotted and variously marked with purple, especially when taken 
from the deeper parts of the quarry. The rough and vesicular condition 
may be seen in Woodbury’s quarry, alsoin Mr. Holt’s; the more even- 
_ bedded in William Habbeler’s. Fossils collected at Genoa have been 
forwarded to the Paleontologist of the Survey, and the reader is referred 
to his report for names and descriptions. 
The Salina shale immediately overlies the Niagara in Ottawa county. 
Along the north shore of Sandusky Bay, in the township of Portage, it is 
an earthy, dove-colored limestone, in beds of two to four inches, which, 
exposed to the weather, becomes quite blue; and being permeated with 
gypsum in small, detached masses, it often crumbles. Some of the beds 
are more enduring, and are, in that case, more brown than blue, weath- 
ering a chocolate. The bedding is quite loose, as if some profound dis- 
turbance had shattered the layers. At the Plaster Beds, owned by Mr. 
George A. Marsh, of Sandusky, the Salina is exposed to the depth of 
thirty feet in quarries which have been opened for gypsum.* Although 
the geological relation of the rock containing the gypsum cannot be ascer- 
tained by examining outcrops within Ottawa county, it is believed to 
hold a place within the Salina, since neither the Niagara nor the Water- 
lime is known to afford this mineral in workable quantities in other 
parts of the country; yet the lithological features of the rock containing 
it are very similar to those of the Waterlime seen in Wyandot and Allen 
counties, Although it here has a thickness of at least thirty feet, at 
Genoa it is reduced to less than a foot, and is seen in the form of a green 
shale, which also, on weathering, turns blue and falls to pieces. It is 
best seen at the bottom of the quarry of Messrs. Newman and Ford, but 
is penetrated also in Wyman and Gregg’s. 
Over the Salina shale the Waterlime is found. This has three distinct 
lithological characters within the limits of the county. It most fre- 
quently occurs— 
1st. Asa coarse brecciated, gray, or drab-gray, limestone, with rough, 
cavernous surfaces, indistinct bedding, or massive, with no fossils. It 
* About 10,000 tons of gypsum are taken per annum from these quarries. It is 
of excellent quality, and is widely sold throughout the western States. 
