446 
GEOLOGY OF THE FIRST DISTRICT. 
of transportation to tide water on the Hudson. The marble trade is already an important 
branch of industry, and. in our territory it must necessarily be one which will rapidly increase 
in value and importance. The marble beds here and in Westchester county are more con¬ 
venient to water transportation than in any other parts of the United States, where the marbles 
are of similar quality. The strata also are thicker, and blocks of almost any desired mag¬ 
nitude can be quarried. The large blocks for the columns of the Girard College, in Phila¬ 
delphia, are quarried in Egremont, Massachusetts, very near the line of Massachusetts and 
New-York. The marble business is one that will always employ many men and much capi¬ 
tal ; and this valuable material is so abundant that it is perfectly inexhaustible in any finite 
period of time, and it will always be an unfailing source of wealth. I consider the resources 
of Dutchess county in valuable marbles as inexhaustible. 
Altered Taconic rocks through the Highlands. 
It was mentioned in the preceding chapter on the Taconic rocks, that in crossing the High¬ 
lands, they were more or less altered, and would be described in this chapter on the Meta- 
morphic rocks. It has also been observed that some of the limestones in Beekman and 
Fishkill, where they approached the Highlands, were white and grey crystalline limestones. 
East of Poughquaick in Beekman, the granular quartz rock was seen, having almost the 
characters of gneiss, and the slate was changed to mica slate. South of Shenandoah in Fish- 
kill, the granular quartz was seen again, and there it was compact and homogeneous like 
eurite, but retained its strata planes. The associated limestones were grey and white. The 
dip was in some places almost vertical to the southeast. 
The granular quartz rock forms a continuous stratum through a portion of Westchester 
and Putnam counties. It is probably a continuation of the stratum described as forming a 
part of Peaked and Elbow mountains in Amenia and Dover in Dutchess county, and is pro¬ 
bably a continuation of that described by Prof. Hitchcock in the west part of Massachusetts.* 
The granular quartz rock crops out on the bank of Peekskill bay of the Hudson river, about 
half a mile northwest of Peekskill landing, near Hall’s point. The strata are nearly vertical, 
leaning a little to the west-northwest. It ranges up the “ Peekskill hollow.” It is seen in 
connection with the iron ore at Bradley’s ore bed in Peekskill hollow, about ten miles from 
Peekskill; and again it occurs near Boyd’s corners, in Carmel, Putnam county. It is quar¬ 
ried to a small extent near Boyd’s corners, for door-steps, hearth-stones, and other purposes. 
It splits out in regular slabs, from three to nine inches thick, and three to seven or eight feet 
square, with an uniform plane surface, and is admirably adapted for a flagging stone for 
streets, cellars, etc. 
The locality near Hall’s point belongs to-, of Peekskill. It is at the mouth of 
Peekskill creek, a little north of Hall’s point; and if is believed that a valuable quarry of 
* Vide Second Annual Report on the Geological Survey of New-York, p. 172; Hitchcock’s Geological Reports of Massa¬ 
chusetts, 1833, pp. 22,321; Hitchcock’s Final Report, 1842, pp. 587,593 ; Dewey, American Journal of Science, Vol. 8, &c. 
