140 GEOLOGIOAL SURVEY OF ALABAMA. 
further inspection of these rocks will show us that they have 
not only been tilted up but have been crushed together, and 
folded in a very complex way, and that rocks which are 
widely apart in the geological scale, are often found in direct 
contact. We shall see, moreover, that these disturbances 
are more profound along the southeastern part of this belt, 
and constantly diminish in intensity as we go northwest- 
wards, so that the strata even in the northwestern part of 
this State, are thrown very little out of their originally 
horizontal position. It is evident therefore, that the strata 
of this region have been subjected to the action of some 
other force than one by which they were merely gradually 
elevated, and that whatever may have been the origin and 
nature of this force, it was much more pronounced in its 
effects along the southeastern border of the disturbed region, 
than further to the northwest. 
The same pecularities of structure and attitude charac- 
terize the rocks of the whole Appalachian region from Ala- 
bama to New York and beyond, and these matters have 
been closely and carefully studied by many of the best 
geologists of the country, the brothers Rogers, Safford, 
Lesley, Dana, and others; most of the peculiarities of -Ap- 
palachian structure have been described, and satisfactory 
explanations of the approximate causes of these peculiari- 
ties have been given. 
No one who will carefully examine the positions of the 
various rocks exposed, for instance, in Jones’ valley, can 
fail to see that these rocks have been pushed up, in such a 
way as to cause their broken or exposed edges to trend or 
run in the general direction of the course of the valley, i. e., 
northeast and southwest, and that most of these rock ledges 
show a dip or slope towards the southeast. This position 
of originally horizontal beds could be brought about only 
through the action of some force coming either from the 
southeast or from the northwest, and compressing them to- 
gether in that direction into much narrower limits than 
they originally occupied, and this compression into narrower 
limits could take place only by the strata being thrown into 
a series of wrinkles or folds, or by their being rent apart 
and one side slipped up over or past the other. There are 
