90 
[Assembly 
quarries, have so much the aspect of gneiss, that close inspection is ne- 
cessary to distinguish them. The limestone rock again appears in the 
bed of a small brook between Harlaem and West Farms village. It is 
thought probable that the West Farms and the Eastchester marble quar- 
ries are in this range of limestone, which passes up the valley of the 
Bronx river by White Plains and Rye pond, and so on further to the 
NNE. 
2d. Another range passes from near Macomb^s bridge in a NNE di- 
rection, is crossed by the aqueduct, and passes about two or two and a 
half miles west of White Plains. 
3d. Another crosses from New- York Island at Kingsbridge, and 
thence ranges NNE, and forms the shore for some distance. 
4th. Another ranges from Dobb's ferry in the same general direction 
by the county poor-house and Ackerman's iron mine. 
5th. Another ranges NNE from Sparta, by Sing-^-Sing, about a mile 
east of Pine bridge across the Oroton river. Some parts of this bed 
are pure white marble; some are dolomitic, and some have the aspect 
of gneiss, until closely examined. 
6th. Another ranges from Verplanck's Point NNE to near Peeks- 
kill, where it changes its direction to the east. A mass of limestone, 
with a transvierse line of bearing, viz. east and west, occurs near Henry 
J. Cruger's mansion, two and a half miles southeast of Verplanck's 
Point. It is supposed to be a displaced, outheaved mass from the pre- 
ceding range, 
7th. Another range extends up the valley of Peekskill creek from its 
mouth, and is a continuation of that in Rockland county, at Tompkins 
and Marks's quarries, associated with the same rocks. 
There are many smaller bodies of limestone, some of which may be 
parts of the above beds, as there are several lines of transverse stratifi- 
cation, and lateral heaves and faults, that, in some places, render the 
tracing of the continuity of the beds a matter of much difficulty, and 
requiring more time than was at my disposal. These beds above de- 
scribed have not all been traced out continuously, and there may be 
some error in some of them, and there may be more beds than have 
been indicated, but these bodies are the principal ones. 
