TACONIC SYSTEM. 
433 
pitches under the limestone. Some of the slate is talcy. The continuation of this range of 
limestone forms the east base of the mountain northwest of Hillsdale village, where the same 
slate rock is also associated (the roof slate), and apparently pitches under it, both dipping to 
the east. The limestone is granular and grey. 
Prof. Merrick examined a locality of pyritous copper ore on Mr. John S. Collins’s farm. 
There was little ore, but the locality showed a bed of “ quartz and feldspar ” in the limestone. 
Mr. C. assured Prof. Merrick that a rumbling noise under ground was frequently heard in the 
vicinity of the “ mine,” just before a storm, and that the ground was often so much agitated 
as to cause a rattling of the windows ! 
Prof. Merrick found a large mass of quartz, similar to that of the flat veins between the 
strata, northwest of Hillsdale. It was several feet wide, and was visible for some distance 
on the surface. 
Dutchess County. 
A mountain mass of the Taconic rocks ranges through Ancram, the east part of Pineplains, 
the west part of Northeast, and northwest part of Amenia.* The northern part in Ancram 
is called Winchell’s mountain. It is composed of slate, talcy slate and chloritic slate, and is 
intersected by numerous veins of quartz. Limestone ranges along the base of the mountain 
on both sides. It is generally grey and blue, though in some places at the eastern base of the 
mountain it is white. 
Local details on this mass. About one and a half miles northwest from the gate, which is 
on the mountain west of Amenia, the slate is chloritic, and is soon succeeded, as we pass 
towards the “ city,”t by talcose slate. A short distance north of the “ city,” the rocks are 
much broken up, and are talcy slate and talcy limestone, and both rocks contain cubic crys¬ 
tals of iron pyrites. The bluish grey and clouded limestone soon succeeds on the west, ap¬ 
parently pitching under the talc slate. In some places this limestone was checkered by veins 
of carbonate of lime and of quartz. Limestone was the rock seen in place from thence to 
Pineplains, except at a place where the road crosses a small stream about half or three quar¬ 
ters of a mile east of the Quaker meeting-house, and here the slate was the rock seen in 
place. 
The country between Ancram furnace and the base of Winchell’s mountain consists mostly 
of limestone, frequently alternating with the slate. The strata are very much deranged, 
broken and contorted. The slate is argillaceous, talco-argillaceous, and like roof slate, and 
in some places intersected and shivered by joints into such small masses as to be called 
* It is to be observed that the different ranges of rock do not conform to the ranges of hills and mountains, but cross them 
obliquely. This instance is one of the examples. The range of mountains which extends from Beekman to Ancram, terminat¬ 
ing near Boston corners in Winchell’s mountain, is formed in its northern part of slate, and talcose and chloritic slates; the 
middle part, of mica slate; and the southern portion, of gneiss, 
t The “ city ” is a small village in the northwest part of Amenia. 
Geol. 1st Hist. 55 
