366 
GEOLOGY OF THE FIRST DISTRICT. 
V. CHAMPLAIN DIVISION. 
GENERAI, REMARKS, 
This division includes those rocks that have been described in the annual reports of the 
First geological district, under the name of the Hudson-river slate series* and Hudson slate 
group. 
It consists of a series of slates, shales, grits, limestones, and siliceous and calcareous brec¬ 
cias and conglomerates. Some plutonic rocks which have been intruded among those of the 
above series, have modified their aspect in many places, and formed metamorphic rocks. 
They will all be described in their proper order. 
The rocks of the Champlain division occupy a belt of country between the Shawangunk 
mountains and the Highlands on the New-Jersey line, ranging thence eastward and north¬ 
ward by Kingston, Saugerties, Coxsackie, Coeymans, New-Baltimore, Schenectady, Ballston, 
Saratoga, Glensfalls, Fort-Ann, and Whitehall, for its western outline ; and with the High¬ 
lands and their extension northwards, a few miles west of the lines of Connecticut, Massa¬ 
chusetts and Vermont for its eastern boundary. On the north, it extends far into Vermont, 
and probably into Canada; on the west, up the Mohawk valley and across the State of New- 
York, and occupies a vast extent of territory in Ohio, Kentucky, Indiana, Illinois and various 
western and southwestern states and territories; to the south it extends across New-Jersey, 
Pennsylvania, Maryland, Virginia, and still farther, but its southern limits have not been 
thoroughly explored. 
In the First geological district of New-York it consists of the following members or groups, 
viz: 
* The division of the fossiliferous rocks of the First geological district, as proposed in the Fourth Annual Report, 
(1840,) was one of convenience, and founded in nature, and as affording means of easily tracing the groups of strata. 
This division of the rocks has been substantially retained by the Board of Geologists, the Hudson slate series being 
divided into the Champlain division and Taconic system, the Catskill mountain series divided into the Catskill and Erie 
divisions, and the Shawangunk series called the Ontario division. Although there is scarcely a doubt as to what forma¬ 
tions in Europe these are equivalent, yet it has been thought preferable to describe groups of rocks as they are, instead of 
striving to identify them with those of other countries, which must necessarily differ from them in some respects. Geolo¬ 
gical equivalents can be settled in a permanent manner, when all the facts of superposition, fossils, and the more or less 
local extent of subordinate strata, shall have been definitely ascertained. If that time has not yet arrived, it is believed 
to be near at hand; the superposition of the New-York rocks and those of several of the other States being now known, 
and the fossils are undergoing a rigid examination. 
