GEOLOGY OF THE REMSEN QUADRANGLE 



31 



below the top of the Trenton. This zone varies from about 8 to 15 

 feet in thickness and is well shown along the path opposite High 

 fall. From this point it may be traced along the sides of the gorge 

 for nearly 2 miles to Prospect village. 



The impure limestone layers of both the folded and the non- 

 folded portions average only a few inches in thickness and are 

 separated by thin shale bands. Within the folded zones the layers 

 are, in rare instances, scarcely folded or broken; sometimes they 

 are gently folded; most commonly they are highly folded or con- 

 torted ; while occasionally some of the layers are broken and pushed 

 or faulted over others. 



Numerous observations show the strike of the folds to be from 

 n. 50 e. to n. 65 e. or practically parallel to the strike of the 

 Trenton fault and also parallel to the very low folds of the Trenton 

 limestone in this region. 



It should be noted that these contorted strata occur only in a 

 very local district. As far as can be ascertained they are visible 

 only in the Trenton Falls gorge and in the bed of Cincinnati creek, 

 1 J miles southwest of Prospect. Along Mill creek, above Graves- 

 ville, the contorted strata do not show in the excellent Trenton 

 section there exposed. 



Cause of the folding. Vanuxem 1 states that the folded layers 

 are more thoroughly crystalline than the layers above and below 

 and that as the material of the disturbed layers was being crystal- 

 lized it caused an expansion which manifested itself laterally by 

 throwing the layers into folds. However a careful study has 

 failed to show any real difference in degree of crystallization and 

 even if such difference could be found it is difficult to see how 

 simple crystallization could bring about such a considerable 

 expansion. 



T. G. White 2 cites Prof. W. O. Crosby as suggesting that the 

 folds may have been caused by the great weight of overlying 

 strata. But this does not explain the sharp and even overturned 

 folds and minor thrust faults which imply a distinct shortening 

 of the layers within the folded zones. 



In some places the structure greatly simulates cross-bedding. 

 White 3 gives photographs showing supposed overlap structure 

 and channel filling. Since these structures are associated in the 

 same zone, with truly folded and broken strata some other ex- 

 planation must be sought. 



1 Geol. N. Y. 3d Dist. 1842, p. 90. 

 2 «N. Y. Acad. Sci. Trans. 15:89-90. 

 3 Op. cit. pi. 3l fig. B and pi. 4, fig. B. 



