22 
GEOLOGY OF THE THIRD DISTRICT. 
CHAPTER IV. 
TACONIC SYSTEM, OR INTERMEDIATE PERIOD; 
(^4 name given by Dr. Emmons, from the mountain range at the east boundary of the State.) 
The want of parallelism between the layers, beds or divisions of the Primary and the New- 
York system, proves a derangement of the first anterior to the deposition of the latter; and 
the rugged or rounded outline, and the smooth surface of the primary at the uplifts where un¬ 
covered, shows it to have been water worn before the deposition of the succeeding class. 
This fact is important, proving that the chain or series of rocks in the third district are not 
complete, and that masses are wanting to fill the intermediate space. To the period which 
elapsed between the two systems, we should place all those parts of the Cambrian system of 
England, which hold a position inferior to the Potsdam sandstone, should any there exist; for 
from observation here, a Cambrian system could occupy none other than the vacant or inter¬ 
mediate space, unless of a particular character. 
Products of the Taconic System , or Intermediate Period. Upon the primary at the north¬ 
east of Lewis county, occasionally patches are met with which belong to this period ; they 
were noticed in the Report of 1840. They consist of lamellar white limestone with specular 
iron ore, and of compact red iron ore ; these occur near Lewisburg furnace, and in the neigh¬ 
borhood of Harrisville. From the lower part of the Potsdam sandstone enveloping the same 
kind of ore, and covering such masses, a connection between the two exists, the sandstone 
being the terminal deposit. 
To this period also the plumbagine rocks at Mr. Cleaveland’s, in Lewis county, are to be 
referred, the whole being obviously what are termed metamorphic rocks, in its proper accepta¬ 
tion. These rocks will again be adverted to under the head of Lewis county. At present 
we would merely observe, that great obscurity exists with respect to them in the district; but 
probably full light will be thrown upon them from observations in the adjoining one, or further 
to the east. The surface of the rocks of the Primary system was without doubt deranged 
and water-worn, before the products in question were deposited upon it; the confirmation of 
which is the covering of a mechanical deposit in the Potsdam sandstone and its conglomerate, 
being the products of broken up and water-worn preexisting rocks. The chief obscurity arises 
from the connection of the same ore, and other products, with the two surfaces, which may 
