234 
TRANSITION ROCKS. 
sylvania; and from thence northeast through the 
State of New- York to Fort Ann, near Lake Cham- 
plain, and follows the east side of that lake to Can- 
ada. The separation of the transition and seconda- 
ry is not so regularly and distinctly traced as that 
of the transition and primitive ; many large valleys 
are formed of horizontal secondary limestone, full 
of shells, while the ridges on each side consist of 
transition rocks. The two formations doubtless in- 
terlock, and are mixed in many places ; but north- 
west of the line above described it is probable little i 
or no transition will be found, while to the south- 
east partial formations do occur. The transition 
formation is generally broadest where the primitive 
is narrowest, and vice versa, and is from 20 to 100 
miles in width ; the stratification runs from a north 
and south to a northeast and southwest direction, 
dipping generally to the northwest, at an angle in 
most places under 45 degrees from the horizon. On 
the edge of the primitive, it deviates in some places 
from this general rule, and dips for a short distance 
to the southeast. The most elevated ground is on 
the confines of North Carolina and Georgia, where it 
descends towards the northwest until it meets the 
secondary. The outline of the mountains of the 
transition formation is almost a straight line, with 
few interruptions, bounding long parallel ridges of , 
nearly the same height, declining gently towards the 
side, where the stratification dips from the horizon, 
and more precipitous on the opposite side, where 
the edge of the strata come out upon the surface. 
The inclined strata are, indeed, so characteristic | 
of this formation, that Mr. Featherstonhaugh re- I 
marks, Wherever the geological student finds the | 
strata thrown out of the horizontal line and dipping ' 
in any direction, he may, with few exceptions, enu- 
merate such hills among the transition rocks, the 
old red sandstone inclusive. Few of the rocks of 
the United States lying above them are found with \ 
