334 
GEOLOGY OF THE FIRST DISTRICT. 
ranges of hills and mountains, and even to the usual line of the emergence of the strata on 
the surface. The southeast angles of the masses, between the intersecting fractures, are 
usually elevated, giving mural precipices on the eastern and southern faces of the hills, while 
the strata dip more or less gradually to the northwest. 
The fact of two great systems of fracture in our rocks, which approach to regularity of 
direction within comparatively narrow limits, and that the southerly ends of masses of strata 
are almost constantly elevated along the traverse lines of fault, while the proper axes of ele¬ 
vation follow the other or longitudinal lines of fracture, has already been adverted to. The 
results of these combined elevations, are echelon movements of the strata. The successive 
ridges sink gradually to the northeast, until they disappear, while they are frequently succeeded 
by other ridges, which are not in the exact lines of prolongation of the former, but obliquely 
lateral to them. These in turn sink, and so on. If the faults are numerous, a serrated or 
broken outline is given to the ridges. 
The same general principles hold true, and much more strongly marked in character, in the 
rocks lying lower in the series, as the Hudson slate group, the Shawangunk grits, and the 
rocks of the Highlands, except that the southwest angles of most of the masses of these latter 
strata have been highly elevated, giving a high easterly dip, and that they have been exposed 
to a greater number of elevatory movements, producing a greater derangement of the stratifi¬ 
cation. 
Most of the streams follow the lines of these two systems of fracture, changing from one 
to the other to produce many of their changes of direction. I have been enabled to trace 
some of these lines of fault across mountains and valleys, for many miles. 
Metallic veins occur in several places along both these systems of fracture; and it is mostly 
in consequence of the echelon movements that have occurred in the strata since their first 
breaking up,* that it is a matter of so much practical difficulty to trace out the continuation 
of metalliferous veins and beds, so as to open them in the most favorable locations. 
Some of the disturbances of the strata about Kingston have already been described. 
The limestone of the Helderberg division emerges from the sandy plains around Kingston, 
about one mile to the east. The strata dip variously in different localities. This ridge is 
within the line of disturbance that crosses the Shawangunk mountains, and extends northward 
by Catskill, Athens, Coxsackie, New-Baltimore, Cohoes falls. Baker’s falls, and still farther 
north. 
On the road from Kingston to Wilbur, about half a mile from Kingston, the limestone con¬ 
taining hornstone, was observed dipping slightly to the west. It is overlaid by the grey lime¬ 
stone. One-fourth mile farther south-southeast, towards Wilbur, the black slaty, scaly lime¬ 
stone (perhaps the cauda,galli grit altered by causes that have upturned the strata) appears in 
nearly vertical laminae, but the strata seams are not highly inclined. Some of the characters 
* There are distinct evidences of at least three elevatory movements, viz. one (at least) before the deposition of the Shawan¬ 
gunk grit strata; another after the deposition of the Shawangunk, Helderberg and Catskill mountain series, and before the tertiary 
epoch; and another at least since that period. 
