COMPOSITION OF THK RIPLEY FORMATION. 593 



Section of Ripley Group ; Chattahoochee River. 



Base of Eocene. 



Feet. 



1 — Massive blue clay ; contains a few bits of teredo-eaten lignite 



2 — White coarse conglomerate, the matrix material being calcareous. The 

 quartzose pebbles decrease in size toward the top, and the stratum becomes 

 more argillaceous. There are many casts of fossils, but all too obscure for 



specific identification 18 



3 — Gray sand, with indurated ledges; no fossils seen; merges gradually in the 

 upper part into a dark (almost black) sand, containing large nodular 



masses and interstratified with light-yellow sands 6o 



4 — Hard sandy ledge; weathered surface jagged ;^light yellow in color, white 



when dry and unweathered ; contains Exogyra costata^ Say, and echinoids- 30 

 5 — Light-yellow sand, interstratified very irregularly with a gray micaceous 

 sand filled with friable Kipley fossils; occurs at mouth of Pataula creek, 



Georgia 30 



6 — Brown laminated argillaceous sand ; disappears at mouth of Pataula creek__ o 

 7 — Gray fossiliferous sands, with bowlder-like concretions. The sand is massive, 



and is fossil-bearing in the lowest 5 feet only 40 



8— Yellow sands and indurated ledges filled with casts of Exogyra cosiata, Say, 

 and echinoids set fast in the ledge. The sands are cross-bedded, and con- 

 tain some lignitic streaks 35 



9 — Calcareous gray clays, with concretions 50 



10 — Light-yellow cross-bedded sands enclosed between indurated ledges 20 



11 — Calcareous sand filled with shells of Exogyra costata^ Say, and Gryphcea 

 mutabilis, Mort. ; contains many indurated ledges, and gives rise to the 

 first bar below Eufaula 70 



12 — A massive gray sand, with a few friable fossils and concretions. This sand 



is only slightly calcareous, and is more or less lignitic 40 



13— Light-gray and yellow sands interlaminated with sand darker in color and 

 more argillaceous than the preceding, and contains bits of lignitized dicoty- 

 ledonous leaves and twigs ; no other fossils seen ; crops out in gullies of 

 Eufaula, Alabama, next below the Orange sand 20 



14 — Gray calcareous sand, with indurated ledges, E. costata, Say; G. mutnbilis^ 

 Mort. ; Hamulus onyx^ Plicatula m^ticosa^ Anomia^ sp. (?) et ah. ; forms the 

 shoal at Frances bar and the bluff at Eufaula 190 



15 — Soft, slightly coherent sand, gray in color ; appears at the mouth of Cowikee 



creek, Alabama GO 



10 — About the same in general character as the succeeding, but contains indu- 

 rated ledges about a foot thick, which serve to indicate numerous rolls in 

 the strata; ends just above the mouth of Cowikee creek, Alabama 170 



17 — Gray fossiliferous marl, shells much decomposed. An occasional lignitized 

 log and numerous slightly phosphatic nodular masses containing fossils 

 occur in this stratum 5 



18 — Gray, glauconitic calcareous sands, weathering into fucoidal shapes and con- 

 taining a few white, soft phosphatic nodules 10 



19 — Fossiliferous marl ; little or no lignite seen ; the marl appearing to be some- 

 what glauconitic 2 



