THE DARLINGS SLIDE SECTION. 161 



somewhat obscured by weathering and the friction of the enormous logs 

 which are rolled over it. It is on the left bank, and the bank opposite 

 is low and apparently of alluvium. 



Section at Darlings Slide. 



1. Superficial sands 3 feet. 



2. Reddish and yellowish streaked sands 18-20 ' ' 



3. Gray aluminous clay (presence or thickness uncertain) \ ^^ u 



4. Chesapeake marl to water (variable) ^ 



Total thickness above water 50 " 



The composition of the several beds is as follows : 



Number 1. — Pale yellowish gray incoherent sand, such as might be 

 deposited by a river during floods — less like beach-sand than the analo- 

 gous material at Alum bluff". 



Number 2. — Of the same character as number 3 of Alum bluff. The 

 material is generally coarser and the gravels a little larger. There is also 

 greater heteros^eneitv in structure. 



Number 3. — The conditions were unfavorable for determining the 

 presence or thickness of the gray aluminous clay, but from the fact that 

 it is well exposed wdth sliarp contacts at Abes spring, but a short dis- 

 tance south, and, together with the Chesapeake, makes up 27 feet of 

 thickness, it is reasonable to suppose that it forms part of the 27 feet 

 assigned to 3 and 4. 



Number 4. — Chesapeake marl, in every respect the same as that forma- 

 tion found at Alum bluff". 



It is notable that nothing below the Chesapeake is visible, although it 

 has been stated that the Chipola beds exist under the gray marl. This 

 can only be an assumption, since, with the water, as we were informed, 

 within a foot of its lowest stage, nothing of the sort was visible, nor does 

 the stream show any material such as would be washed out of the older 

 Miocene beds, if present. The principal fossil here, as at Alum bluff", is 

 Mactra congesta, Conrad, with which are associated Venus mercenaria. L., 

 and Tavrltella variabilis^ Conrad. The beds above the Chesapeake appear 

 to be destitute of fossils. 



Below Abes spring the banks of the Chipola become lower and swampy 

 and the river enters the so-called Dead or Chipola lakes, noted as a fish- 

 ing ground, through which it connects with the Apalachicola by a cut- 

 off. Seaward from this extend the great swamps of the coastal plain. 



Thomasville, Georgia. — On the line of the Savannah, Florida and West- 

 ern railroad leading toward Albany, Georgia, and from half a mile to a 

 mile from the center of the town, there are several cuts which give good 

 exposures of the reddish gravels which cover most of this region and 

 have been referred to the Lafayette formation. These beds contain much 



