STRUCTURAL GEOLOGY. 



505 



bent so as to form great arches or great troughs with many minor undu- 

 lations on the flanks of the larger, they are designated as geanticlines, or 

 antidinoria (Figs. 394 and 395), and geosynclines or synclinoria (Figs. 396 



Fig. 396.— Synclinorium: diagrammatic. (Van Hise, U. S. Geol. Surv,) 



Fig. 397. — Synclinorium, Mt. Greylock, Mass. (Dale, U. S. Geol. Surv.) 



Z'Sch. 



-' \\ \ 



i-wm mn^m 



1 S< h r "E Sch, 



\S>-:--:::::;:<;- 



Sch. \\'\\\] 2Sch. /^- ■:::::•■::: ■■■■■':-■ Ull'fE.Sch. 



u I i \^-^^=-yy//j' 



Fig. 398. — A series of diagrams illustrating actual field relations in regions of folded 

 strata. Westchester Co., N. Y. (Dana.) 



and 397). Folding is often accompanied by the development of slaty 

 cleavage (p. 440). 



