1 88 WILLIAM H. HOBBS 



Fan (carinate) anticlines may thus be a result of backfolding, 

 though they may possibly in other cases be due to compression 

 under the action of equal thrusts from opposite directions. It is, 

 on the other hand, extremely difficult to conceive of conditions 

 which could give rise to a fan or carinate syncHne, for the reason 

 that syncHnes, Hke anticlines, should develop above the zone of 

 maximum pinch (see Fig. 19, p. 179). It is thus with a certain 

 satisfaction that we may contemplate the abandonment of the 

 conception of the Glarus double-fold, which in an earlier generation 

 was standard doctrine in tectonics and required us to account for 

 supposed fan synclines upon a gigantic scale (see ante, Fig. i, p. 76). 



