232 GEOLOGY OF OHIO. 
responds, in general, with that in the island of Mackinac, although it 
shows at the latter place a greater thickness, and is not separated by a 
belt of regularly laminated beds into two portions. Yet this tendency to 
the rough and brecciated condition has been seen even in the very bottom 
of the formation. In the quarry of Messrs. Newman and Ford, at Genoa, 
there are irregular masses of porous and brecciated rock, which, by ce- 
menting and breaking up the bedding, give the formation a massive 
structure. In the bed of the Portage, in section 9 (Harris), there are sin- 
gular, dome-shaped masses of rough and vesicular, or brecciated, Water- 
lime, standing out six to eighteen inches ahove the glaciated surface, on 
which the even beds (phase No. 8), which are thin, seem to have been 
deposited unconformably, or are arranged concentrically about the mass. 
The following downward section covers all the quarries at Genoa: 
SECTION AT GENOA. 
Nova Lininebedsyaltoysumchestdirallomecsssscceceetaecerereeceeee ese nes 1 foot. 
No. 2. Brecciated and carious, with cavities and fossils........... 6 to 12 feet. 
INows; Green shale. weathering: blue) iets. -c-eoneeececiosenes cseene 1 foot. 
INoy4 Niagara (Guelph) beds Sito, Gyimchess.c...terssesseseccnnoees 16 feet. 
The quarries of Messrs. Newman and Ford, and of Wyman and Gregg, at 
Genoa, are in the base of the Waterlime. Other quarries at the same 
place are situated in the top of the Niagara. 
The Waterlime underlies a strip about two miles wide north and south 
along the western end of the county, and a large area in the center. It 
also crosses “the Peninsula” through the townships of Rensselaer and 
Danbury. 
The Drift in Ottawa county has not been so carefully observed as in 
adjoining counties, yet it is believed not to be an exception to the 
general view which has been taken of the Drift deposits in the Fourth 
District. The banks of the Portage consist, wherever seen, of unmodi- 
fied Drift. The upper six to eight feet are of a ight brown color, and 
the first two or three very rarely contain stones or gravel. It is, perhaps, 
to some extent made up of a re-deposit of the finest parts of the hard- 
pan, incident to the sifting agency of the waves and currents of Lake 
Erie when it stood at a higher level; but it is generally too gravelly to 
admit of that origin, and its finest parts, if deposited in that way, can 
not be separated or distinguished from those parts of the unmodified 
Drift which are also very fine, and which graduate insensibly into it. In 
general, also, such re-deposits by the action of Lake Erie consist of sand 
with no stratification, while this fine clay is seen sometimes, as at Toledo, 
to be handsomely arranged in horizontal and oblique laminations, with 
alternations of very fine sandy layers. 
