406 
GEOLOGY OF THE FIRST DISTRICT. 
Along the eastern base of Merino mountain, the limestone forms a thick mass, underlaid 
apparently by the brecciated limestone. About one and a half miles south from the 
tavern at the south end of the salt marsh, the strike was N. 20° E., and dip 45° to 
50° to the east-southeast. 
5. The limestone in the west part of Hillsdale. 
6. The limestone beds in Milan, crossed by the Pineplains and Rhinebeck turnpike, one 
and three-quarter miles west of Lafayette corners. The rock here forms a mass one 
or two hundred yards in breadth on the surface. It is compact, fine-grained, subcrys¬ 
talline, and much is more or less “ sparry ” in consequence of its being traversed by 
veins. It probably dips under slate on the east (though the contact was not seen), and 
is succeeded by slate of a similar character on the west. 
A similar limestone is found in the east part of Redhook township, and in Clinton, 
ranging through the west part of Milan. 
7. The limestone near Lithgow post-oflSce, on the road from Poughkeepsie to Amenia. 
8. Another similar limestone, but blacker, on the same road, about one mile from Washing¬ 
ton hollow. 
9. The limestones near Fishkill, Matteawan, Sprout creek, Poughquaick, &c. These lime¬ 
stones in Fishkill, Beekman, Pleasant-valley and Washington, are more or less altered 
by metamorphic action. 
10. The limestone of Smith’s clove in Orange county. It is abundant and well exposed to 
view near Galway’s tavern, and may be seen in many places thence northwards to¬ 
wards Cornwall landing, with nearly vertical strata. Red slate is sometimes asso 
ciated with this rock, as also with the 9th, 8th and 4th ranges of limestone, 
Brecciated and Conglomerate limestone. 
This limestone seems to have been formed by the breaking up of the Mohawk and Trenton 
limestones, and of the Calciferous group; and after the fragments had undergone more or 
less attrition, to have been cemented together. Very numerous localities of limestone of this 
character have been observed, most of which are in Columbia county. It often presents an 
aspect like the Potomac marble, but contains, in most of the localities observed, fragments 
of hornstone, basanite and siliceous matter in greater or less abundance, that would render 
it difficult to saw or polish. 
Localities. —1. The brecciated and conglomerate limestone may be seen to great advantage 
at the stone quarries in the north part of Stuyvesant, on the bank of the Hudson (Vide Sec¬ 
tion, PI. 23, fig. 8). The strike of the rocks at these quarries is about N. 10° W., and the 
dip about 30° to 40° to the eastward. The stone that is quarried is a greenish slaty rock of 
a fine-grain, with thick layers divided by joints, so as to present perfectly plane faces. The 
stratum quarried is thirty or forty feet thick,* and is represented by (6) in the section. This 
* This rock is used for basements and foundations of houses, etc. in Albany. It has a fine grit, and would perhaps answer 
as a rubstone instead of the Scotch hone. 
