FOURTH ANNUAL REPORT 
Of W. W. Mather, Geologist of the First Geological 
District of the State of New- York. 
To his Excellency William H. Seward. 
Sir : — 
Since the last report, I have been engaged ni explornig the geo- 
logical phenomena of the counties of Sullivan, Delaware, Ulster, Greene 
and Schoharie. 
Of the twenty-one counties of the First District, sixteen have now 
been examined, viz : Suffolk, Kings, Queens, Richmond, New-York, 
Westchester, Putnam, Dutchess, Columbia, Rockland, Orange, Sulli- 
van, Ulster, Delaware, Greene and Schoharie. 
I had supposed that so much of the next season would be devoted to 
the geological survey, as would complete four years from the dates of 
the several commissions, and perhaps more than this, to enable the va- 
rious individuals, not only to complete their field labors, but also their 
final report of the survey. It is now understood that the survey will 
close on the first of July next. As there are five counties in the First 
District which are yet unexamined, they cannot be explored in the shor^ 
time remaining, with the same degree of attention that has been bestow- 
ed upon the others, and which I should give to these, had I the time I 
had expected. 
PRELIMINARY OBSERVATIONS. 
The general physical features and aspect of the country, as well as 
the agricultural and mineral value, are dependent on its geological struc- 
ture and mineral composition. There are four distinct groups of rock 
formations in the region examined the past season, each of which de- 
