ONTARIO DIVISION. 
365 
show the extension of this rock to the north on the east side of the Hudson, in Dutchess and 
Columbia counties. The rock was seen in hundreds of localities in those counties, in Rens¬ 
selaer and Washington counties, and in Vermont. I infer that these red rocks are the same 
range, and of the same age as those extending from Canterbury, through Bellvale mountain 
by Long pond, to Green-pond mountain in New-Jersey, for the following reasons, viz : 
1. It IS an apparent extension of the same geological formation in the same direction. 
2. The rocks have similar general characters and geological associations, though frequently 
modified in appearance by causes contemporaneous with, or subsequent to the period at which 
they were placed in their present highly inclined position. 
3. There are no rocks of similar color and characters, lower in the geological series ; and 
none higher, except those of the Catskill division ; but these latter have not similar geologi¬ 
cal associations, and besides they have a vastly greater thickness, where they are undisturbed, 
not many miles distant. 
In some places the same red rocks occupy two or three parallel belts, one or two miles from 
each other. Limestone was frequently seen associated with these red rocks in the valley of 
Smith’s clove in Orange county, and in the counties on the east of the Hudson river; but no 
fossil remains were observed in it at any other place than Townsend’s iron mine in Cornwall. 
These red slate and grit rocks, like some others that will be described in the Taconic 
system, cross the belt of primary mountainous country called the Highlands, from north- 
northeast to south-southwest, and emerge on the southeast side, but they pursue a course 
parallel to the ridges of the Highlands.* 
The period of the elevation or tilting of these rocks into their present highly inclined posi¬ 
tion, will be considered in another part of this volume. 
* There are no continuous ridges of mountains in the Highlands, of more than a few miles in length, in consequence 
of the interruptions caused by dislocations and lateral heaves of masses of the strata. The hills of similar rocks succeed 
each other in echellon lines, which seem to have been caused by lateral heaves along the lines of fault. In consequence 
of this, neither the line of outcrop nor the line of bearing is parallel to the general direction of the Highlands, but ridge 
succeeds ridge, each of which runs out and diminishes in height until it disappears in a northwardly direction below the 
rocks, which are generally considered of more recent origin. For example, a traveller passing in Rockland county from 
southwest to northeast, along the base of any of the large hills of a mountain, if he continues his course without turning 
off to the east, around the point of a succeeding mountain, will soon find himself in the midst of the Highlands. If he 
be travelling in the opposite direction, along the base of one of the mountains, and continue his course, he will find him¬ 
self receding farther and farther from the mountains as he passes each succeeding terminating hill. If he be travelling on 
the northwest flank of the mountains, the reverse will hold true; and progressing southwest from Cornwall, New-Wind- 
sor, or Newburgh, he will soon find himself entering the mountains, and following through the valleys, will emerge on 
the southeast face of the Highlands. These valleys are called “ cloves,” and Smith’s clove is a noted example. It is the 
one through which the New-York and Newburgh turnpike passes, without ascending more than a few hundred feet, 
and is frequently referred to in this volume. 
The Ramapo river flows through this clove to the south, while another stream, a branch of Murderer’s creek, flows in 
the opposite direction. The Erie railroad crosses the Highlands through the south part of Smith’s clove, to near the head 
of the Ramapo. 
