46 Foerste — Eocene and Miocene of Georgia and Florida. 



Thickness of the Flint River section. 



The data for an exact determination of the dip the Eocene 

 southwards are not yet secured. Prof. Raphael Pumpelly 

 determined the level of the base of the Chattahoochee to be 

 102 feet above the sea at Glenn's Well, and 155 feet above the 

 sea in Powell's limesink. The first of these localities is 5 

 miles from the river almost directly east of Russell Springs, 

 and 4 miles south of Bainbridge on the Coon-bottom road. The 

 base of the Chattahoochee outcrops again along the Flint River 

 at the localities 14|-, 17-J, 18, and 19, but little above the water's 

 edge. The river localities are about 6 miles south of the line 

 of strike of the Chattahoochee at Glenn's Well. The precise 

 level of the river where the Chattahoochee outcrops is not 

 known, but a dip of 13 feet to the mile is considered at the 

 present state of our knowledge to be amply sufficient to 

 account for the facts. * At this rate the .thickness of the 

 Vicksburg section, from the Bainbridge marl to the Chatta- 

 hoochee overlying it, would be 150 feet ; the massive siliceous 

 bed along the Flint River 6 miles north of Bainbridge would 

 be 70 feet below the Bainbridge marl, making a total section 

 of 220 feet, with the possibility that these thicknesses are 

 overestimated. The figures on the accompanying sketch map 

 will sufficiently indicate the intervals between the different 

 silicified layers. 



Chief characteristics of the Flint Fiver section. 



The chief characteristics of the Flint River section are : 1, the 

 comparatively great thickness of the silicified beds 6 miles north 

 of Bainbridge ; 2, the Bainbridge marl with its abundant echi- 

 noids and other fossils loosely enclosed in a cement of which 

 Orbitoides forms the main element ; 3, the long interval be- 

 tween layers d and e ; 4, the more sandy character of the 

 layer g at Lambert's Island; 5, the great amount of soft white 

 limestone in the upper part of the section, interrupted only by 

 the siliceous layer h. 



Correlation of the Marianna section with layers b to e of the 

 Flint River section. 



In a corner of the sketch map the Marianna section has 

 been introduced. It shows the road leaving Marianna on 

 the east, crossing the Chipola River, and then turning 

 northwards, for several miles, after which a road through 

 fields finds its irregular path to the Natural Bridge. It is 

 better to secure a native as a guide here. The section was 



* Loc. cit., page 445. 



