468 
GEOLOGY OF THE FOURTH DISTRICT. 
In the ravine west of Warsaw, some of the Gardeau rocks are exposed; and in the ravine 
southwest of the village are found rocks of the upper part of the Portage group, though 
mostly destitute of the characteristic fucoid. In this ravine there is a waterfall of one hundred 
and ten feet, which, together with the rocks above and below, gives a thickness of two hun¬ 
dred feet at this place ; they are principally shale with thin layers of sandstone. 
The upper part of this group may be seen at the falls on Allen’s creek, near the north 
line of Gainesville, and about three miles south of Warsaw village. On elevated ground from 
Sheldon to Warsaw, this mass, with its vertical fucoid, appears in several places along the 
road. 
The swamps in this county containing muck, are exceedingly numerous. This deposit, in 
the Fourth geological district, has in but few instances become sufficiently tenacious to be 
called peat; though it burns as readily, and is equally good for fuel ; but in drying, it falls to 
powder. In many places, when the swamps shall have been drained, and time allowed for 
the muck to become more compact, and other vegetation to succeed the present, many of 
these deposits will furnish valuable fuel. 
Near Batavia, several small swamps or ponds contain marl, and also the springs or ponds at 
the source of Spring creek. About three or four miles north of Leroy, between the gypsum 
beds and Bergen, there is a large marl swamp ; the extent of the deposit I did not learn, but 
it is probably great, resulting as it does from the marls and slates of the gypseous formation. 
Two and a half miles south of Leroy, on the land of Archibald Stewart, and an adjoining 
farm, a marl bed covers about twenty acres, with an average depth of probably eight feet; a 
few rods from the margin being five, a little distance farther nine, and the centre fifteen feet. 
This marl is covered by muck, from one to two feet thick. Mr. Stewart has applied the marl 
as manure, and finds ample returns. 
In examining Silver lake, I found the bottom in many places covered with a growth of Chara, 
which, when first thrown out, looks green, but on a little exposure it becomes white and brittle, 
readily crumbling to powder ; they are almost wholly composed of carbonate of lime. The 
same species is found abundantly in the outlet of the Caledonia spring; and so rapid is its 
growth, that frequent removals are required to prevent it from impeding the water in the 
sluiceways to the mills. Towards the inlet, the bottom of this lake is covered with marl 
several feet deep, but I was not able to ascertain whether it occupied the whole area. From 
sounding, the bottom appeared soft. The marsh at the head of the lake was not examined, 
though it probably contains marl. 
In all deposits of tufa and marl, a large quantity in the bottom of the bed is earthy, and 
considered unfit to burn for lime ; these portions, either in their actual state or burned, can be 
advantageously used for agricultural purposes. Lime burned from this, and made into a com¬ 
post with the black muck of swamps, would be an excellent manure for all the lands of the 
southern counties ; and even the hardpan, which is considered almost worthless, may be 
reclaimed, and rendered fertile by the judicious application of muck and lime. The impor¬ 
tance of this subject cannot be too strongly urged. While the farmer is perhaps cultivating a 
