480 
GEOLOGY OF THE FIRST DISTRICT. 
Duck-cedar pond,* a few rods east of a little swamp.t The lower part of the figure illus¬ 
trates the appearance of the rocks as seen at one part of the cliff, which is perhaps forty feet 
high above the debris at its base, and shows the interlamination of the trap or connpact green¬ 
stone between the limestone beds, the position of the granite on one side of the limestone, 
and the gneiss rock on the other. The right-hand part of the figure is intended to show a 
ground plan of the position of the rocks, with the lateral faults to which they have been sub¬ 
jected along the transverse lines ; but by being badly copied, the shading or coloring by which 
the different rocks in each of the heaved masses was distinctly recognized by the eye has been 
omitted. The left-hand compartment of each of the three masses is granite; the second, 
limestone ; the third, trap ; the fourth, limestonethe fifth, trap ; the sixth, limestone ; and 
the seventh and succeeding ones are gneiss in nearly vertical strata, ranging N. 20° E., as 
represented in the section, A mass of the adhering limestone and trap from this locality, is 
placed in the State Museum of Natural History at Albany. The junction of the two rocks 
is a perfectly defined line, one nearly black, the other white ; and there is no blending of one 
into the other, but both are perfectly characterized up to the plane of contact. At the locality, 
these different rocks are as perfectly defined for many feet in the face of the cliff. The 
minerals observed in the limestone at this place, are crystallized mica in hexahedral prisms, 
green spinelles, hexagonal scales of plumbago, sphene, and sahlite. The sphene is very 
abundant in some places at this locality, and the specimens look so much like those from 
Rogers’s rock near Ticonderoga, that they could not be distinguished. The sphene is im¬ 
bedded in a green augite, with scales of plumbago. 
(c). MetamorpMc limestones of the Highlands of Putnam county. 
These are similar to those described in Orange county, only spinelle has not been recognized 
in them, and brucite is not common. Serpentine, augite and asbestus are more common, and 
garnet is more common in the associated rocks. 
Local details. — 1. Limestone was observed about one and a half miles south of Putnam 
court-house, on the farm of a Mr. Townsend, at two old mine holes, where some have supposed 
that silver, and others that marble was the object of exploration. It is scarcely necessary to 
add, that no traces of silver ore could be distinguished. Both these excavations are in a bed 
of limestone about thirty rods apart. The bed is narrow, perhaps twenty feet wide, and is 
bounded by gneiss on each side ; the strata are highly inclined to the east-southeast. Brucite 
and some coccolite were observed in the limestone of the northwardly excavation. At the 
other locality the limestone is very white, coarse grained, and contains imperfect crystals of 
phosphate of lime or green augite. 
2. A bed of limestone containing brucite, serpentine and asbestus, is associated with the 
* This pond is called, on Burr’s county map, “Truxedo pond.” 
t By being badly copied, this swamp is represented on the figure as a small pond. 
