206 J. D. Dana on the origin of the Earth’s Features. 
of these beds: indeed, the ripple-marks, the marine plants, &c., prove 
that the sea in which these deposits were successively made was always 
shallow. The accumulation could thus only have been made by a grad- | 
ual subsidence of the ocean-bed. The greatest depression 
along the line of the greatest accumulation ; and, in the direction of the 
thinning margin, the settling would ss. By this process, as te a 
lower side became gradually curved, rents and fractures upon that side : 
» 49. 
“The direction of the waves formed by the settling of any wide area 
will be parallel to the great synclinal axis; a fact already stated in bd 
! Rogers. Th i a 
d th 
determined the elevations existed long before the production of the moun- 
* See his note to page 48, and pages 53, 54. 
