APPENDIX 
To L. Vanuxem's Report. 
ECONOMICAL GEOLOGY. 
Lake Marl and Tufa. — Several deposites of marl and tufa occur in 
ihe limestone region in the northern part of Otsego. South of the 
limestone range, these deposits diminish in extent and proportion as 
the calcareous alluvial diminishes. Several small deposits were for- 
merly known in the southern range of counties ; but these, from their 
limited extent, have become exhausted. Along the southern part of the 
town of Cherry- Valley, at the outcropping of the drab limestone, are 
several deposits of tufa and marl, which are deposited by streams 
issuing from the limestone above mentioned. At the sulphur springs, 
below the falls, north of Cherry Valley, also on the farm of Mr. Schism, 
in the neighborhood, are deposits of this substance. 
Cortland marl ponds. — A short distance west of Cortlandville are 
three marl ponds which supply the neighborhood with lime. From the 
remoteness of these deposits to limestone, and the purity and white- 
ness of the lime when burned, they are highly valuable, and the lime is 
much sought for by the inhabitants of the more southern counties, for 
whitewashing and other common purposes to which lime is applied. 
These three ponds are near each other, and cover an area of twenty-five 
acres. The quantity of marl in some of these ponds is said to be gradu- 
ally increasing, notwithstanding the quantity which is continually being 
taken from them. There are several small marl ponds in the northern 
part of Cortland county. 
Peat. — A few deposites of this substance have been discovered in 
Otsego county. On the farm of Mr. Clark, two miles south of Coo- 
perstown, is a small peat swamp, nearly surrounded by alluvial hills, 
[Assembly, No. 50.] 49 
