210 SOD ITES THOR SCHL ENS: 
which friction gave less resisting power. The ideal figure prob- 
ably more nearly illustrates the effects of nature in passing 
downward from the central line than in passing upward, for the 
deformation in superficial strata may be accomplished by joint- 
ing, faulting, and brecciation. 
WV ee 
FIG. 4. 
} 
FIG. 5. 
If beds above and below the central one be folded in a simi- 
lar fashion, the limbs of the different layers will be closely 
pressed together or thinned, or both, and at the anticlines and 
synclines there will be spaces between the layers, or thickening, 
or both (Fig. 5). Butthis result can only be accomplished by plastic 
flow of the material of the limbs toward the areas of relief. This 
often produces minor plications at the crests and troughs. Even 
where the folding is only moderately close the limbs of folds 
