444 
GEOLOGY OF THE FIRST DISTRICT. 
About one mile and a half southeast of Kline corners, near the line between Kent, Amenia 
and Dover, heavy beds of close-grained granular quartz were observed. This rock seems to 
form also a portion of the mountain ranging southwardly, which is called Elbow mountain, 
and that ranging northwardly, called Peaked mountain in the Reports.* The east side of 
Elbow mountain trends nearly south ; and the west nearly in a southwest direction. The 
north end presents a sharp summit, but opposite Dover it is three or four miles wide. The 
quartz rock may be easily examined on the road from Kline corners to Kent, in a field on the 
north side of the road. It contains some small black crystals in some places, which are pro¬ 
bably hornblende or black tourmaline. 
This quartz rock is believed to be the same as the Potsdam sandstone, only altered by its 
proximity to granitic and intrusive rocks; and the same as the quartz rocks described by 
Professors Hitchcock and Dewey, associated with gneiss and mica slate in the western part 
of Massachusetts. Between this granular quartz and the Housatonic river in Kent, are three 
rocky ridges composed of gneiss, gneissoid horblende rock, and granite. The latter was seen 
only in veins and loose blocks. The other rocks were frequently seen in place, and are like 
those of the Highlands. On the road from Columbia furnace in Kent to Hitchcock’s corners, 
the only rocks seen abundantly were gneiss and gneissoid hornblende, containing some magnetic 
oxide of iron. Some of the quartz rock is nearly white, and would probably answer for the 
manufacture of glass. 
Economical applications of the Metamorphic limestones. 
The granular limestone of Columbia and Dutchess counties is very extensive, and does 
not yield to any other mineral deposit in those counties, in prospective value. Marble quarries 
are extensively wrought in some parts of this range of limestone, and many others will un¬ 
doubtedly be opened. The limestone extends through the greater part of the length of these 
counties, and crops out with a variable breadth from a few hundred yards to several miles. 
It varies much in texture and color. It is granular and compact, white, gray, clouded, striped, 
and nearly black. In some localities it is strong and difficult to break; in others it is dolomitic 
and very friable, and crumbles to sand by exposure to the weather. The limestone beds of 
this range are interstratified with talcose and micaceous slate. They dip to the east and east- 
southeast from twenty to ninety degrees. It is rarely used except as a wall-stone. Lime 
has been made from it in Amenia and some other places. It makes a strong and good lime. 
The calcareous sand, caused by the disintegration near the surface of many of the beds of 
dolomitic limestone, may probably be used with advantage on the soil as a substitute for marl. 
It is found by experience that the lime of these dolomites does not injure vegetation, like that 
of the European magnesian limestones ; and the rock here is pulverulent, and ready to act on 
vegetation in the same way as marl, and may, it is believed, be used with similar results upon 
soils that are not calcareous. 
Vide Second Annual Geological Report of New-York, 1838, p. 172. 
