CHAMPLAIN DIVISION. 
405 
to New-Jersey; the eastern preserves throughout its usual positions. A small portion of this 
limestone is found in Minisink, on the west side of the Drowned lands. This occurs at a 
point where the Walkill makes a considerable curve to the east. 
“ On Big island, in the Drowned lands, some of the layers of this rock are oolitic, in several 
places near the village of Warwick; also half a mile north of New-Milford.”* 
On Pochunk neck, this limestone, also nearly horizontal, is associated with the subjacent 
calciferous rocks. It occurs also in several places associated with the rocks of the Calciferous 
group, which will next be described. 
There are numerous beds of limestone upturned and interstratified in the Hudson valley, 
the real geological ages of which are not known with certainty, but are supposed to belong 
to this group. Some of them may belong to the Water-lime group of the Helderberg division, 
but if they do, they seem to have lost all traces of the fossils usually associated with those 
rocks. The rocks of the Hudson valley are so much confused by derangements subsequent 
to their formation, that close, detailed and multiplied observations ohly can unravel the ex¬ 
tremely complicated geology of that region.! 
The following localities show beds of limestone that are supposed to belong to the Mohawk 
limestone, but' they have not been examined with such care as to render it certain. 
1. The west side of Canaan mountain, Columbia county, and at Whiting’s mills in Canaan. 
2. The dark colored limestone, in Kinderhook, about three miles east of the village, and west 
of Kline creek. It may be seen near Mr. Crocker’s, in five successive ridges ; some 
is sparry, and some is brecciated. 
3. The same kind of limestone, in the limestone ridges in Ghent. Some of this limestone 
is sparry, some is dark colored and compact, and some is brecciated. It is nearly 
vertical, and is in successive echellon ridges (Vide PL 23, fig. 6). 
4. The limestone along the eastern base of Merino mountain, near Hudson. This limestone 
is also seen on the road from Johnstown to Oakhill ferry, south of Blue hill. The rock 
is the blue limestone, sometimes grey or sparry, about thirty feet thick where observed, 
interstratified with slate, the junction with which was seen. The strike was N. 10° W., 
and dip 60° to 80° eastwardly. 
The same rock, it is supposed, was seen outcropping by the road-side on the farm 
of John E. H. Plass in Livingston, about five miles from Hudson. Its strike is 
N. 20° E., and its dip 70° to 80° eastwardly. Its junction with slate is visible. 
* Dr. Horton’s Geological Report, 1839, p. l.'iO: Third Annual Report of New-York. The oolitic rock probably belongs to the 
Calciferous group, like that of Warwick in Orange county, and Greenfield and Galway in Saratoga county. 
t Had I the opportunity, it would give me much pleasure to spend some years in minute detailed investigations in this 
interesting region. The tracing out the continuity and extension of the fractures and lines of disturbance and fault trans¬ 
verse to the main axis; their connection with the metalliferous and other veins; the determination, more exact than has 
yet been done, of the periods at which the various derangements of the strata, elevation of. mountains, injection of trap, 
quartz, granite, and various ores, were effected; the period when metamorphic agency changed many of the rocks, tracing 
definitely what rocks have been changed in their characters, and to what extent, by that agency; the determination of 
the equivalents of several anomalous rocks interstratified with the rocks of the Champlain division, are among the desi- 
derata of questions connected with the physical geology of that region of country. 
