43° 



TERENCE T. QUIRKE 



flexed slightly, one paraffin member started to split down the 

 center along a plane parallel to the surface in the manner of a 

 bending column (Figs. 5 and 2). 



Chamberlin and Miller^ had obtained similar low-angle breaks 

 when they caused rotational strain in a paraffin short block, 

 thereby proving their contention in favor of the importance of 

 rotational strain as a cause of low-angle faulting. The writer 



/ ^--^ 



Fig. 4. — A wide sheet of soap which failed under rotational stress by combined 

 compression and bending. The dimensions of this piece are 21*0X4X1*1) inches and 

 the contour lines are equidistant. They indicate the place of rupture. 



has used a rotational stress and bending sheets rather than short 

 blocks in order to be consistent in the general treatment and 

 object of the paper and for the sake of the mechanical considera- 

 tions which are treated later. 



Analysis of the rupture of sheets and columns under translatory 

 forces. — -Long columns and sheets fail by bending and by rupture 



' Jour. GeoL, XXVI (1918), 35, and Fig. 16. 



