THE TP3RTIARY GEOLOGY OF IHE 
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vaviou, division, -vhiol, collec.ivoly cl.amcterize the formation along tlm Atlantic and 
, ; c .>v„ I i„„itic “Buhrstone,” “Ckibornian,” and “Jacksonian - 
ullirtLe hav; ..ot ^t been clearly made out. The Buhrstone app^rs to 
" p the greatest extent; at any rate, whether correctly or incorrectly it is hefoi^a- 
Tn generally referred h. as the typical Georgia Eocene. 'Ihe Jackson doubtless enters 
lie Le along the southern border, although I am not aware that it, existence there 
has been deflnltelv determined through the character of its fossil remains. Mr. Ruffin s 
detc-rmination (1) of the “Great Carolinian Bed” (= Jacksonian) in Slid Bluff, 
on the Savannah River, has already been referred to in our description of South 
Carolina and needs no further comment here Leaving aside the probable existence 
in' tlie State of the Oligocene formation, as would seem to be indicated by the Georgiana 
bed or bed containing tlie giant Ostrea Georgiana, overlying the marl deposits 
(Ruffin’s “ Great Carolinian ”) of Shell Bluff, it is almost positive that the formation 
in qiK'stion occupies some little, if not a considerable section of the lower Tertiary 
area, continuous with the area occupied hy the same formation in Florida The later 
Tertiary deposits occupying the Atlantic border, and having an extent landward of 
about (iO miles, ore probably continuous with, and doubtless of the same age as the 
later Tertiary deposits of South Carolina, and are accordingly referred to the Miocene. 
'I'Ik’ 'I’ertiary deposits, which in their entirety occupy considerably more than one- 
half the area of the State, doubtless rest upon a Cretaceous floor, and abut for the 
greater part of their extent upon rocks of Archman age. Their inner boundary cor- 
responds approximately with a moderately sinuous line running from near (a little 
outside of) Augusti, on the Savannah, hy way of Macon, Fort Valley, Montezuma, 
Americus and Cuthbert, to Fort Gaines, on the Alabama frontier.* 
* Siiu-«" tlic i>rfi>arntion of tlic alwve the writer has received, through the kindness of the author, Dr. 
l.oiighridge'R notes on tlie geology of tlie State (Keport on the Cotton Protluction of the Stale ot Georgia, pp. 
14-1(1; extracted from tlie Teiitli Census Reports, 1884), which, unfortunately, are too brief to add very 
ninterinlly to our knowleilge of tliis division of the geological history. The following section, taken from Mr. 
t^ingleton. is given of Shell Uluff, Burke Co. : — 
1. Resl loam hill tops, ....... 15-25 feet. 
2. White sandy marl, coarse sand and oysters — Oitrea Oeorgiana, . 10 feet. 
8. Coarse drift and shell fragnients, ..... 2 feet. 
4. Shell licil — 0. Ueorgianii, . . . . , . 13 feet. 
6. White sandy marl, ....... 00 feet. 
6. Indurate marl, with casts of small shells, .... 2 feet. 
7. AVhite sandy marl, ....... 6 feet. 
8. Indurate marl, with casts of shells and few 0»trea sellaformis, . 3 feet. 
9. llanl yellowish white marl, ...... 4 feet. 
10. Oyster-lH'd— O. trUtrfonnin, ...... 1 foot. 
11. llanl marl, ........ 5 feet. 
12. OysU-r-lxHl— O. neUtpformis, , . . . . . 6 inches. 
13. Hard yellowish-white marl, ...... 10 feet. 
14. Fine yellowish sandy marl, ...... 6 feet. 
15. Yellowish-white clay marl, ...... 2 feet. 
10. Indurate marls, with shells, ...... 2 feet. 
17. Whitish-gray clay marl (to water), ..... 15 feet. 
The beds containing 0,lrm Gtorguma arc referred to the Vicksburg series ; Xo. 5 not improbably represents, 
e t or n part or in whole, the “Jacksonian,” while the lower portion of the blulf is doubtless largely of the 
