CHAMPLAIN DIVISION. 
369 
other counties named, (and portions of Columbia, Dutchess, Orange, Ulster, Greene, Albany 
and Saratoga, might also be mentioned,) the rocks are the same, but the strata dip at a high 
angle, the rock more readily crumbles by the action of the weather on its edges, while the in¬ 
clination of the strata enables the water to sink and be conducted off between the layers and 
through the joints of the rock, to break out in springs at a lower level. The hilly character 
of these counties also enables the water to drain in part from the surface more freely than if 
the lands were more level, and the consequence is a mellow, warm and dry soil. The rocks 
here spoken of range through Orange county, between the Highland and Shawangunk moun¬ 
tains ; thence through the east parts of Ulster, Greene, Albany, Schenectady and Saratoga, on 
the right bank of the Hudson; and through the west part of Dutchess, Columbia and Rens¬ 
selaer counties, on the left bank of that stream. This range of rocks occupies a diagonal 
belt of country in the county of Washington. 
1. HuDsoN-iiivER Group. 
Synonims. Frankfort slate growp, Frankfort slate and ruhblestone, Greywacke, Greywacke slate, 
G. shale, Slaty greywacke, Transition argillite, Pulaski shales. Green slate and rubblestone, of 
the Annual Reports Greywacke and Metalliferous greywacke of Eaton. No. 3 of the Penn¬ 
sylvania Survey. 
The rocks of this group are mostly slates, shales, and grey, slaty and thick-bedded grits, 
that have heretofore been called Greywacke slate, Greywacke shale, Greywacke, and Slaty 
greywacke. The slates and shales are generally dark brown, blue and black ; and the grits 
are grey, greenish and bluish grey. They are stratified and conformable, alternating a great 
number of times without any regular order of alternation. 
These rocks contain/eto fossils except fucoids, and these are extremely abundant in some 
of the strata. There are at least five species which will be figured and described in the Pa¬ 
laeontological Report. The species above alluded to are found in the slates and shales, but 
there are others on the surfaces of the slaty grits peculiar to these rocks. 
A few specimens of testacea only have been found in this group, although it is well ex¬ 
posed to view over a great extent of^ country in the First geological district. A few were 
observed at the falls of the Walkill at Dashville, Ulster county, and near the villages of Walden 
and Sugarloaf in Orange county. 
The thickness of this group could not be accurately ascertained in any part of the Hudson 
and Champlain valley, in consequence of the rocks having been deranged, upheaved and 
tilted in almost every direction, where they are visible; but in the valleys of Norman’s kill, 
the Mohawk river, and the Schoharie kill, they are beautifully exposed to view, and can be 
'studied with any required degree of minuteness. The rocks in those valleys, and those of 
their tributaries in Albany, Schenectady and Schoharie counties, dip at small angles to the 
west-northwest, west and southwest. No actual measurements of these strata have been 
made, but it is estimated that they have a thickness of from five to eight hundred feet. 
Geol. 1st Dist. 47 
