The object of this paper is to compare the complex systems of folds and the structures of two different chains of mountains.
A direct parallelism is not expected, because of the differences in orogenies, evolution, and location. But certain common features may be pointed out which offer new aspects on the origin of the mountain chains in general.
As introduction, a description of the two systems is given, then the comparison is developed, leading to the conclusion that a part of the Piedmont-New England area may be similar to the Alpine geosyncline before it was deformed by the last phases of intense napping at the end of its paroxysm of shortening. Some pre-Alpine nappes may be compared with klippes of the Blue Ridge.
The writer is fully aware of the hypothetical and general character of this paper. He intends, nevertheless, to introduce some new factors in the structural analysis of two major chains of the earth.