220 DR. THOMAS STERRY HUNT ON THE 
nearly horizontal and rest in undisturbed succession on the crystalline rocks of the 
Primary series. To the east of the lake, however, and thence southward along the valley 
of the Hudson, is found the belt of disturbed strata, dipping generally to the eastward, 
which had been called by Eaton, the First or Transition Graywacke, the distribution of 
which has been given in § 5. This belt, described by Emmons as consisting of a great 
thickness of green, red and gray sandstones and conglomerates, with green, purple and 
black slates, and some associated limestones, was by him now referred to the horizon of 
the Loraine shale and the succeeding sandstones, (Nos. 6, 7, and 8), or, in other words, to 
the Second Graywacke, lying above the Trenton limestone; which latter, according to 
Emmons, appears, in some localities, to dip beneath this graywacke. By Eaton, however, 
the strata of the same belt had been assigned, under the name of the First Graywacke, to 
a position below the same Trenton limestone. 
§ 10. These views were published by Emmons in 1842, at which time, as we see, he 
dissented from the opinion of Eaton as to the stratigraphical horizon of the First Gray- 
wacke of the latter, and adopted that which had been put forth by Mather, to be men- 
tioned below. As regards the quartzite and limestone of the Primitive series, and the 
Transition Argillite, which, according to Eaton, intervene stratigraphically, as well as 
geographically, between the crystalline schists of the Primitive and the First Graywacke, 
Emmons supposed that these three divisions constitute a distinct group or series, which, 
from its development in the Taconic hills of western Massachusetts, he named the Taconic 
system. This he regarded as distinct from, and older than the New York system lying 
to the westward of it. 
$ 11. The survey of the Southern district of New York was assigned to Mather, who, 
in his final report on the region, in 1843, described the southward extension of the various 
groups of rocks just mentioned, and maintained, in opposition to both Eaton and Emmons, 
that the Taconic system of the latter was a modification of the Champlain division; the 
quartzite being supposed to correspond to the Potsdam, the marble to the Calciferous, — 
Chazy and Trenton, and the argillite to the Utica and Loraine ; for which latter sub-division 
he adopted, as a synonym, the name of the Hudson slates. 
ÿ 12. As regards the graywacke-belt east of the Hudson River, this consisted in part, 
according to Mather, of the same slates in a disturbed and altered condition, and in part 
of higher strata, belonging to the horizon of the Oneida and Medina sub-divisions of the 
New York system. He supposed, with Eaton, that the belt of these rocks, continued from 
Canada, through Vermont, and along the east side of the Hudson, was prolonged southward, _ 
on the west side, in the Shawangunk range; and that the Green-Pond Mountain range, in ; 
New Jersey, was also a portion of the same belt, which it lithologically resembles. Thus, in 
the view of Mather, the whole series of Eaton, from the granular quartzite of the Primitive 
up to the top of the Second Graywacke, was made up of the rocks of the Champlain 
division, with some still higher strata. He confounded the First with the Second 
Graywacke, and supposed both the clay-slates of the former, and the underlying Transi- 
tion Argillite of Eaton, to be nothing more than local modifications of the Utica and Lor- 
aine shales. Indeed, as is well-known, Mather went so far as to regard the Primitive 
crystalline schists themselves as a farther modification of the same Champlain series. 
Emmons, as we have shown, while adhering to the views of Eaton in other respects, 
adopted, at this time, Mather’s conjecture as to the horizon of the eastern gray wacke-belt. 

