Great Synclinal in the Taconic Range. — 269 
miles. The line of ridges, after dwindling to a low narrow 
strip in Salisbury, continues on southward; and this continua- 
tion is geologically a part of the range, although it does not 
bear the name on maps; but of this more southern portion I 
do not now propose to treat. 
The general conclusions presented by me in earlier papers, 
published in this Journal from 1872 to 1881, are fully sus- 
eed by my more recent studies, and I therefore briefly state 
them. 
First; as to the rocks. The schistose rocks constituting the 
Taconic Range vary gradually, as we go from north to south, 
from argillyte or roofing slate and the smooth, faintly crys- 
talline hydromiea (or sericite) schist, to chloritic mica schist, 
and still coarser kinds of mica schist containing garnets and 
staurolites. 
the uplift is anticlinal, or synclinal, or monoclinal. But in — 
other wider portions the beds of the two sides dip toward the 
axis of the range, and often at a small angle, thus exhibiting 
the fact that in such parts the structure is synclinal, and ren- 
dering it probable that it is so elsewher 
trdly: as to the unity, or not, of the eastern and western lime- 
stone belts. These belts of crystalline limestone, one. extending 
along the east side of the Taconic Range, and the other, less 
continuously, along the western, blend with one another through 
road low regions or valleys crossing the Taconic line, and thus 
prove that they are portions of one formation. ; 
ourthly : as to the stratigraphical relations of the limestone and 
schist. The great limestone formation passes underneath’ the 
schist of the Taconic Range as a lower member in the mountain 
synclinals; and, consequently, the eastern and western lime- 
stone belts are outcrops of opposite sides of such synclinals. 
© give the proof on this point for a part of the range is one 
of the objects of this paper. 
Fifthly: as to the age of the limestone and schist. The lime- 
stone,' which is part of the Taconic system, and, as just stated, 
an underlying member, contains, at various points in central 
Vermont and eastern New York, shells, corals and crinoids of 
younger than it, are of Jater Silurian age, and Sees, of the 
foe of the so-called Hudson River group or Upper Llandeilo 
ags, 
