New York State Museum Bulletin 
Entered as second-class matter November 27, 1915, at the Post Office at Albany, N. Y., under 
the act of August 24, 1912. Acceptance for mailing at special rate of post- 
age provided for in section 1103, act of October 3, 1917, authorized 
July 19, 1918 
Published monthly by The University of the State of New York 
Nos. 249-250 ALBANY, N. Y. SEPTEMBER-OCTOBER, 1921 
The University of the State of New York 
New York State Museum 
Joun M. CLarKE, Director 
THE MAGNETITE IRON DEPOSITS OF 
SOUTHEASTERN NEW YORK 
BNP IRS Ig QOILOIN. 
INTRODUCTION 
A belt of ancient crystalline rocks, complex in structure, origin 
and composition, extends in a general northeasterly direction from 
the Schuylkill river at Reading, Pa., across the northwestern corner 
of New Jersey and through southeastern New York, crossing the 
Hudson river diagonally between Fishkill and Peekskill into Putnam 
and Dutchess counties, New York, and extending from Putnam 
county eastward into the edge of Fairfield county, Connecticut, and 
southward across Westchester county to Manhattan island. 
This belt forms a part of the older Appalachians, and is known in 
southeastern New York and the contiguous portion of New Jersey,,. 
as Ihe Highlands. Included within it, in both New York and 
New Jersey, are bodies of magnetite of considerable commercial 
importance. It is the purpose of this bulletin to review briefly the 
history of the geology of the Highlands, to present a short descrip- 
tion of the general geologic setting of these magnetite bodies in 
southeastern New York, to speculate on the origin of them, and to 
describe the ore bodies themselves from a commercial and operative 
point of view. : 
| Location of the Ore Bodies 
Magnetite is a very common accessory mineral in the crystalline 
rocks which form the Highlands of southeastern New York, but 
the distribution of this mineral in the form of masses of commer- 
cially valuable ore is by no means uniform. The minable bodies of 
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