276 REPORT OF THE AMERICAN COMMITTEE. 
Claiborne. — The lower part of this division which is character- 
ized by the prevalence of shells of Ostrea Sellceformis, is by far 
the most widely distributed and persistent as to quality of 
all the Tertiary formations. It has been identified in all the 
States of this region from Texas to Maryland. A notable feat- 
ure in some localities is the highly ferruginous character of some 
of its rocks, connected in all probability with the great abundance 
of glauconite. 
White Limestone, or Vickshurg. — This is another widely dis- 
tributed and persistent formation, which if made to include also 
the Jackson beds, may be seen from Texas to South Carolina. In 
Florida the White Limestone underlies a very considerable part 
of the peninsula.* 
In the following tabular presentation of the Eocene as it occurs 
in Alabama, the Jackson has been placed with the White Lime- 
stone, with which it is always very closely related, both in litho- 
logical characters and in surface distribution : 
Character and Subdivisions of the Eocene of Alabama. 
Thickness, feet' 
r Coral Limestone, . . . 150 T 
Upper 350 feet, White Limestone .... ■! Orbitoidal Limestone, . 140 \ 350 
1^ Jacksonian, 60 J 
f Claiborne 150 ) .c^ 
Middle 450 feet, Claiborne of E.W.Hilgard | Buhrstone 300 i 
Hatchetigbee, .... 175 
Wood's Bluff, .... 85 
Bell's Landing 200 
Nanafalia, 200 
Naheola, 150 
Black BlufiF, 100 
Midway, , 25 , 
OLIGOCENE. 
If the name Oligocene is to be retained for any of the strata of 
the Gulf series, it will probably be applied to certain rocks de- 
scribed by L. C. Johnson as directly overlying the Eocene white 
limestone which forms the substratum of a considerable part of 
the peninsula. In this connection, Mr. Johnson says : " We have 
no Oligocene unless in the nummulitic rocks of Florida, seen best 
in the Gulf Hammock regions of Hernando, Levy, and Wa- 
kulla In a few spots, these (the Vicksburg rocks) are 
covered over by a variation of which I am not certain. The 
* Am. Journal Science, vol. xxi., April, 1881. 
Lower, 930-950 feet, Lignitic . 
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