34^ -A- Winchell on the Tacon'ic Question. 
I. Original proposals of the founder of the 
Taconic system. 
1. Date of first dcjinitlon. The tei'm Taconic system was 
first employed by Dr. Ebenezer Emmons, in the final report 
on the geology of the second district of New York, the preface 
to which is dated January i, 1S43.' 
The conception of the system existed in his mind, as he tells 
us, long before. "When, in 1S36, I determined that in New 
York, the Potsdam sandstone was the base of the Silurian system, 
it seemed that we had at that time, the base of the sediments; 
but when two years subsequently I had observed the same base 
resting on sediments still older — as those along the eastern side 
of Champlain and elsewhere — it became evident that there was 
still a series older than the Silurian. The proof of this has 
been accumulating ever since; and the Taconic svstem is found 
to rest upon primary rocks without an exception ; and it has 
now been observed through the whole length of the states, from 
northeast to southwest. It is worth}- of note, that through this 
whole extent, the base is continuous."''' 
2. Stratigraphical positioi/. "A group or system of rocks 
which belong evidentlv to a position between the primary of 
the Atlantic ranges of mountains and the New York system." 
That is, between the crystalline schists and the Potsdam sand- 
stone. This was a first formative conception of the stratigra- 
phic limits of the system. It would be antici^^ated that the pre- 
cise limits would be fixed by subsequent observations. For in- 
stance, the rocks naturally referable to the system might not 
always rest on the crystalline schists; and on the other hand, tlie 
upper limit might not finally be fixed at the base of the Pots- 
dam sandstone. 
3. Geograf)hic position and distribution. The typical rocks 
"lie along both sides of the Taconic range of mountains, whose 
direction is nearly north and south, or for a gi^eat distance par- 
allel with the boundary line between the states of New York, 
Connecticut, Massachusetts and Vermont. The counties [in 
1 Constituting chapters VII. VIII, and IX. 
2 American Geology, pt. II., The Taconic System. [Albany, 1S55,] 
pp. 5 and 6. 
