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GEOLOGY OF THE FIRST DISTRICT. 
CHAPTER VII. 
TACONIC* SYSTEM. 
This system consists of slates, limestones, and granular quartz rocks. They form a belt 
of mountainous and hilly country, from Vermont to Peekskill on the Hudson river, along the 
eastern line of New-York, across the counties of Washington, Rensselaer, Columbia and 
Dutchess to the Highlands, and a narrow belt across the Highlands to the mouth of Peekskill 
creek. They reappear on the right bank of the Hudson between Stony point and Caldwell’s 
landing, and range south-southwest until they disappear beneath the Red-sandstone formation 
near the Minishecongo creek in Rockland county, southwest of Stony point. They occupy 
also a variable breadth of country in the southwest part of Vermont, and in the western part 
of Massachusetts. 
The strike and dip of the rocks of this system are in the same directions as those of the 
Champlain division, and apparently overlie them. The dip is to the east, east-southeast and 
east-northeast, at angles varying from fifteen to ninety degrees. Although the rocks all dip 
in the same general direction, similar strata at no great distances are frequently reversed in 
their relative order of superposition. This is more frequently observed on the opposite sides 
of ridges of hills and mountains. 
It will be observed by consulting the numerous sections between the Hudson and the lines 
of Massachusetts, Connecticut and Vermont,! that the talcose slates that belong to the Taco- 
nic system are not confined to the belt that has been described as ranging along the east line 
of the State of New- York to the Highlands, but that local patches of it are found in many 
jlaces. The rocks of this system are more or less distinctly characterized where they ap¬ 
proach to gneiss and granite rocks, and where quartz has been intruded most abundantly 
among them. 
Where the exact order of superposition of these rocks and the primary can be examined, 
* This name is also frequently -written Taghkanic and Taconick, but formerly Toghconnuck and Toghconnuc. The name Ta- 
conic System was given by Prof. Emmons, to designate the rocks forming the Williamstown mountain range. They are very 
peculiar in their aspect, but blend into the Champlain division on the one hand, and into the Primary rocks on the other. 
t Vide Plate 12, fig. 8; PL 13, figs. 3, 4, 5, G; PI. 14, figs. 1,2,3, 4,6; PI. 16, figs. 1,3; PI. 17, figs. 1,2,3; PI. 18, figs. 1, 
2; PI. 23, figs. 2, 4, 5; and PI. 28, fig. 1. 
