MECHANICS OF FORMA TION OF ARCUA TE MOUNTAINS 197 



the trough of the neighboring syndine (a slight elongation of the 

 vertical diameter). Elsewhere at all points on either side of the 

 points of inflection of the fold a more complex deformation has 

 taken place, for the circles have been transformed into more or 

 less elongated obovate figures with the greatest elongation at the 



Fig. 3 1 . — Steeper limb of the anticline produced from a pile of paper to show the 

 deformed guide circles (traced) : a, enlarged diagram at the point of inflection to show 

 the actual migrations of particles by shearing movements parallel to the lamination; 

 h, enlarged diagram of the deformations at the point of inflection if the stratum bent 

 had been from isotropic material. 



points of inflection. Comparing the upper and flatter with the 

 lower and steeper limb of the anticline, we find that deformation 

 has been greater in the steeper limb, and since we are seeking the 

 locus of maximum deformation we will examine this limb somewhat 

 more in detail (Fig. 31). 



Above the point of inflection of the limb it is to be noted that 

 the originally vertical diameters of the guide circles now diverge 



