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R. T. CHAMBERLIN AND F. P. SHEPARD 



parallel type, and when there was considerable thickening on the 

 crests of the anticlines. Conversely synclines grew larger with 

 increasing depth, but the change in the case of the synclines was not 

 so marked as in the case of the anticlines. Thus it might appear 



Fig. 7. — Same model as Fig. 6, compressed to total of 8 inches. Cavity has disap- 

 peared with more intense folding. Other tiny cavities have developed where the folding 

 is gentle. The overturned fold of Fig. 6 has become nearly upright. 



Fig. 8. — Reverse face of Fig. 7 model. Pressure from the left. Vertical variations 

 of folds. 



that the shortening was decreasing with depth, but the apparent 

 difference was made up by faulting in the lowest layers. Antichnes 

 which have rounded curves near the upper surface pass into pointed 

 folds beneath. This is one step in the dying out of folds. SHppage 

 between layers has played an important part in the process. 



