STRUCTURAL FEATURES IN THE FOOT-HILL REGION. 269 
ponents, secondary to that just noted, and acting in direc¬ 
tions more or .less normal to it, B (Fig. 1), were evidently 
periodical in character. They reasserted themselves with 
The profiles I-IV, inclusive, may be regarded as transverse (north and 
south) sections of this secondary fold in the several stages of its develop¬ 
ment according to the geological time represented by each. Figure 1 is 
more particularly a diagrammatic representation of the condition of affairs 
at the close of the Laramie or at a point in time somewhere between this 
and a stage early in the deposition of the Denver formation. 
By the post-Laramie movement the strata were bent up against the range 
nearly at right angles and afterwards truncated by erosion. This effect is 
produced in the figure by supposing a slice of the block represented, to have 
been turned down through an angle of 90°, as if hinged along the line C D. 
The hinged portion is thus a diagrammatic representation of the superficial 
outlines, as shown in detail by the map. 
special intensity at the close of the Niobrara, effecting almost 
entirely at this time the pronounced elevation under discus¬ 
sion, c (Fig. 1), the cross-section of which is that in profile 
IV. The Montana, Laramie, Arapahoe, and early Denver 
