SOME EXPERIMENTS IN FOLDING 



501 



But in the earth, where the stresses operate more slowly and the 

 greater length of time allows more extensive readjustment by recrys- 

 tallization, it is less certain that faulting should increase in relative 

 importance with increasing depth. Down to considerable depths, 



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Fig. 5. — Model of six layers. Layers consisted of equal parts paraffin and vaseline 

 except layer 4 (3 par., i vas.). Original length 25^ inches; shortened 9 inches. Ink 

 line follows base of layer 4. Pressure from the right. 



Fig. 6. — Original length 22 inches; compressed 4^ inches. Layers i, 3, 5, 7, 9 

 and II were i paraffin, i vaseline. Layers 2, 6 and 10 were i par., 2 vas. Layers 4 

 and 8 were 3 par., ^ vas., i plaster. Cavity developed under gentlest of the three anti- 

 clines. Folds developed first near the two extremities with less deformation in the 

 middle portion. Pressure from the right. 



this might be the case, but at still greater depths faulting would 

 doubtless gradually be replaced by the phenomena of rock flowage. 

 With layers of uniform competency. — In the models having several 

 layers a variation in the folding from the top layers to the bottom 

 ones was generally very marked (Figs. 5-8). Anticlines became 

 less pronounced in lower layers, both when the folding was of the 



