VIRGINIA. 



183 



deposit exists in that region at the depth of 558 feet below the surface, overlaid by Miocene and 

 Pliocene beds, and resting upon an Eocene deposit identical with that which underlies it at Rich- 

 mond. ' We are thus assured of the great extension seaward of this deposit, and have the means 

 of estimating the thickness of the Tertiary formations as far east as the mouth of the James 

 River. 



