320 
[Assembly 
Marl. 
In the town of Savannah, shell marl occurs, underlying the Cayuga 
marshes. This is exposed by the Erie canal, where it passes through 
the marsh, to the depth of several feet. It is white and earthy, and con- 
tains abundance of fresh water shells, of the genera Lymnea, Physa, 
Planorbis, Valvata, &c. and is covered by vegetable mould and peat. I 
was informed by a farmer on the east side of Crusoe Island, that the 
marl was met in digging at the edge of the marsh. 
One mile west of Newark, a bed of shell marl appears in the banks 
of the Erie canal. It is whitish, and contains shells similar to the pre- 
ceding. The depth of this bed is unknown, but it is probably small. 
It extends about one mile along the course of the canal. 
In the south part of the town of Williamson, at Cooper's swamp, is 
a thin bed of whitish marl, containing shells similar to the preceding. 
The calcareous marl above mentioned consists principally of carbo- 
nate of lime, with a little vegetable matter, and is in an earthy or friable 
state, perfectly adapted to employment as a manure. We are not 
aware, however, that it is at present applied to any useful purpose; but 
w^e conceive that it is equal in value to our western plaster, and may be 
a better application to some lands. We would suggest to the intelli- 
gent farmers in the vicinity of the Cayuga marshes, who may penetrate 
this marl in the course of ditching, to make a comparative trial of this 
article with the neighboring plaster. 
Gypseous Marl. 
Plaster marl (the local name) occurs at many points on the Erie ca- 
nal, and extends south into the adjoining county of Ontario. It gene- 
rally appears as a soft slaty rock, or as an indurated marl, of an ash gray, 
and sometimes a greenish colour. It is the gangue of the gypsum or 
plaster, in this, as well as in the neighboring counties. This marl ge- 
nerally contains an appreciable proportion of lime, although in some in- 
stances it is entirely argillaceous. Although of the nature of rock when 
first extracted, upon exposure to the air it slackens and crumbles down 
in a short time. We are not aware that it is used as a manure, but 
without doubt to sandy soils its addition would be very profitable, 
perhaps as much so as the plaster which it affords; inasmuch as soils 
purely sandy require clay as well as lime to give them a proper charac- 
ter of composition. 
