SECOND ANNUAL REPORT—STRATIGRAPHIC GEOLOGY. 
119 
Number 2— Of the same character as number 3 of Alum Bluff. The ma¬ 
terial is generally a little coarser and the gravels a little larger, and there is 
also greater heterogeneity in structure. 
Number 3.—Same as number 4 (aluminous clay) of Alum Bluff. 
Number 4.—Chesapeake, just as at Alum Bluff. 
Darlings Slide and Section.—On the Chipola River, a mile or more north 
of Abes Spring, is a “slide” where timber is cast into the river for the con¬ 
struction of rafts, which are floated down the river to the mills at Apalachicola, 
on the Gulf. This place is locally known as Darling Slide, and is a very steep 
natural bank, affording an excellent section, though 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 Darling Slide. 
4. Superficial sands .. 3 feet. 
3. Reddish and yellowish streaked sands... 18-20 feet. 
2. Gray aluminous clay (presence or thickness uncertain). 27 feet. 
1. Chesapeake marl to water (variable). 
Total thickness above water. 50 feet. 
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 analogous material at 
Alum Bluff. 
Number 2. —Of the same character as number 3 of Alum Bluff. The ma¬ 
terial is generally coarser and the gravels a little larger. There is also greater 
heterogeneity 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 
with sharp contacts at Abes Spring, but a short distance 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 formation 
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 Turritella variabilis, Conrad 
The beds above the Chesapeake appear to be destitute of fossils. 
From Dali’s discussion in an earlier part of this paper he appears 
to have regarded No. 1 of each section as Pleistocene and No. 2 as 
Pliocene, 1 and he correlates the “aluminous clay” with the Pascagoula 
formation and the “Chesapeake” (Choctowhatchee) marl with the 
Chesapeake of Virginia and Maryland. 
1 Ibid. pp. 169 and 170. 
