TUK OZAKK ri'I-lFT 



103 



sedimentation uninterrupted attained a vertical nieasurenient of 1S,0()0 

 feet. The period oi' wliich there is no measurahle record in one i)art of 

 the region (inds in an adjoining district sediments of greater significance 

 than all the Coal Measures immediately above the break. 



Here, then, is a case in which on the one side of an old shoreline is 

 the land area that sut!ered profound denudation and on the other the 

 water area in which sedimentation was carried to a prodigious extent. 

 In point of time one is the exact equivalent of the other. 



ROLE OF THE OZARK UPLIFT 



Heretofore in the considerations of Paleozoic stratigraphy in the Mis- 

 sissippi basin the Ozark dome has been made much of. This has been 

 particularly noticeable in the case of the Coal Measures. The Ozark isle 



Periods 



OJilahoman 



ML 



issouriarv 



Des Moines 



Northern Section 



Southern Section T hickness 

 1000' 



Arkansart 



M^msieoua. 



2000' 



1200' 



laooo' 



1700' 



FiufRE 2.— Carboniferous Deposition in the Western Interior Basin (black wantimi). 



has been a favorite theme to dwell on in explaining the sedimentation 

 of the region. 



It has been recently shown in a conclusive manner that the Ozark dome 

 can not be taken into account in considering the deposition of the Coal 

 Measures of the region. The present Ozark uplift is Tertiary in age. 

 During the deposition of Lower Carboniferous the area occupied by the 

 dome was sea, in which limestone was being deposited. When the 

 Arkansan series was laid down the Missouri area was a land surface, but 

 a coastal plain of moderate relief, which later was covered by water. 



