CURVATURE OF STRATA 139 
the flexures which show this arrangement being termed 
Isoclinal folds (see Figs. 26, 27). As the original crowns 
of the anticlines have invariably been removed, the truncated 
beds present the deceptive appearance of a great series of 
strata, all dipping at high angles in the same direction. In 
reality, however, as a glance at Fig. 27 will show, the same 
beds are again and again repeated, so that the series is not 

Fic. 28.—RECUMBENT FOLD. 
by any means so thick as it might at first seem to be. This 
structure is very well developed in the Southern Uplands of 
Scotland. Recumbent fold (Fig. 28) is the name given to a 
flexure, the axial plane of which approaches horizontality. 
A 

fs 
Zyy by Yj 
ts “Yi 
FIG. 29.—ANTICLINAL DOUBLE-FOLD. 
It is a structure of frequent occurrence in regions of highly 
convoluted strata, but is not so common as the ordinary 
overfold. Another structure, particularly characteristic of 
the more highly disturbed portions of the earth’s crust, is 
that known as an Anticlinal Double-fold (see Fig. 29). In 

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