MoCiee — Gulf of Mexico as a measure of Isosiasy. 18< 



DE.GRADATiC> 

 ARLA 



DEPOSITION 

 AREA 



MISSISSIPPI 

 RIO GRANDE. 



YANG-TSt-KIAN 

 HWANG -HO 



5 









o 







DAN 



JBE. 



< 







DNIESTER 









DNIE, 



PLR 



* 







DON 





< 





OT 



HE.R 



RIVLRS 





VOLGA 

 URAL 



GANGES 

 BRAHMAPUTRA 



M. 



mn 



high declivity, 

 over the Plains 

 by reason of 

 late Tertiary 

 elevation, in 

 the northern 

 interior be- 

 cause of the 

 easily eroded 

 late Pleisto- 

 cene drift, in 

 the Comber- 

 1 a n d plateau 

 and the west- 

 ern Appalach- 

 ians by reason 

 of a late 

 Tertiary eleva- 

 tion to which 

 the streams are 

 not yet adjust- 

 ed, in nearly 

 a 1 1 parts b y 

 reason of 

 seasonal storms 

 or vernal snow- 

 melting ; i n - 

 deed by far the 

 greater part of 

 the area stands 

 so high above 

 base-level that 

 the activity of 

 degradation is 

 fairly compar- 

 able with that 

 of the other 

 great tracts of 



_ 



the globe. In 

 the third degra- 

 dation tract in 

 extent (that of 

 the Plwang-ho 

 and Yang-tse- 

 Kiang) unload- 

 ing is unques- 

 tionably pro- 



