ANTICLINORIA; SYNCLINORIA; GEOSYNCLINES 799 



flexures of strata are sometimes spoken of as monoclines, but these 

 are in reality strongly asymmetrical anticlines. They may be spoken 

 of as monoclinal flexures, but should not be spoken of as monoclines, 

 (Figs. 181-183.) 



Fig. 181. A, recumbent isoclinal fold, with over- and undcrfolds. B, mono- 

 cline due to faulting. C, corresponding monoclines, due to ero- 

 sion of an anticline. 



Anticlinoria and synclinoria. When a succession of anticlines 

 has such a relationship as to make a large anticline, it is called an 

 anticlinorium. The central massif of the Alps may be taken as an 

 illustration. In like manner a large synclinal fold composed of a 

 succession of minor folds is a synclinorium. Such a condition exists 



Fig. 182. A simple monoclinal 

 flexure. 



Fig. 183. The same passing into a 

 fault. 



in the Mount Grey lock massif of western ]\lassachusetts. (Figs. 

 184, 185.) 



Geosynclinc and forcdccp. The term "geosyncline" was pro- 

 posed by Dana for the long trough which formed to the east of the 

 Appalachian old land during Palreozoic time. In this trough some 



