:U4 MR CADELL ON EXPERIMENT A.L RESEARCHES IN MOUNTAIN BUILDING. 



The strata hitherto subjected to thrusting were horizontal, but to ascertain if the same 

 .system of reversed faulting could originate with beds at different inclinations, I arranged 



Fig. 6. 



Fig. 7. 



a series of beds dipping away from the pressure board (fig. 6). The structure produced 

 differed in no respect from that exhibited in fig. 3. The inclined shear planes can be 

 readily traced crossing the inclined beds nearly at right angles. The figure is reduced 

 from an accurate tracing of the section obtained. 



In fig. 7 the beds dip towards the pressure board, and the thrust-planes run in direc- 

 tions nearly parallel to those of the bedding planes, and have the effect of " staving " the 

 strata together in such a way as to increase their apparent thickness. On the right the 

 ends of the beds next the pressure board show a tendency to become drawn out at 

 the expense of their breadth. The attenuated strata take a wavy form as they are 

 crushed in and made to assume a steeper inclination than when undisturbed. These 

 little undulations are also seen on the right limb of the anticline in fig. 4, and originate 

 as soon as the strata next the pressure board begin to roll backwards and approach 

 vertically. The tendency of each wave is to break and pass into a small normal fault, 

 as seen in this figure and in fig. 12 below. 



Fig. 8. 



A syncline was formed in the box, and the edges were covered unconformably by beds 

 of sand. On applying pressure, the thrust-planes cut both sets of strata indiscriminately 

 as in previous cases (fig. 8). 



These experiments, relating to different arrangements of strata of the same rather 



