370 
GEOLOGY OF THE FIRST DISTRICT. 
Beautiful sections of parts of this group of rocks may be examined on the Schoharie kill, 
at and near Burton’s bridge, and in numerous localities between that place and Esperance ; 
also at the bend of the Schoharie kill, between Central-bridge and Sloansville, and near the 
mouths of Vly creek and Cripplebush kill; and on the Mohawk near the aqueduct, the banks 
of the Norman’s kill, two miles southwest of Albany, and numerous places on the shore of 
the Hudson. 
Among the undisturbed strata, we see none of the diagonal cleavage of the slate rocks, 
which is so common a character of the deranged strata of the Champlain division, throughout 
their extent in the First geological district.* 
The rocks of this group occupy a large part of Orange, Albany, Schenectady, Saratoga, 
Washington, Rensselaer, Columbia and Dutchess, and small portions of Sullivan, Ulster and 
Greene counties. 
Locat, detaius of the Huuson-river group. 
Orange County. 
Dr. Hortont describes the rocks of this group under the name of Transition argillite, and 
says, 
“ This rock occupies a large extent of surface in this county. Its general direction is 
north-northeast and south-southwest, varying to northeast and southwest. Some ridges and 
elevations differ considerably from this course; but these are partial, and extend only short 
distances. Its color differs from light ash grey through all shades to black. Its hardness, in 
some localities, being the softest kind of clay slate; in others, hard and siliceous; while 
others still possess this property in all intermediate degrees. It is every where regularly 
stratified, although the strata in many places are singularly bent and contorted. 
“ Its dip is uniformly to the southeast, differing considerably in its amount in different 
places. In some localities its position is nearly vertical, while in others the angle of its dip 
will scarcely reach thirty degrees. Perhaps the angle of fifty degrees will be nearest that of 
its general dip. A little way from the western base of the Highlands, it extends from near 
the line of New-Jersey in the town of Warwick, uninterruptedly to the Hudson river in 
Cornwall, New-Windsor and Newburgh. On the west side of the Walkill river, the same 
rock comes out of New-Jersey, and passes down this stream until it enters Ulster county, 
and in all this course there is no rock resting upon it. 
“With the exception of the two ranges mentioned above, it is often overlaid by other 
rocks; these will be noticed hereafter. It forms the bank of the Hudson, from about three 
and a half miles above. Newburgh, to Cornwall landing, which may be about nine miles. 
" Vide Plate 10, figures 3, 4, 5, 6, 7, 8, 9, 10; PI. 29, lateral figures; and PI. 38, fig. 10. 
t Dr. Horton was employed as one of the assistants on the Geological Survey, to make the detailed examination of Orango 
county. 
