GEOLOGY BETWEEN APALACHICOLA AND OCKLOCKNEE RIVERS. 3 1 
SECTION AT CHATTAHOOCHEE LANDING. 
The section at Chattahoochee Landing is made along the public road lead- 
ing from Chattahoochee to the river. The exposure begins about one-fifth 
mile from the river, and is measured along the public road a distance of perhaps 
somewhat more than one-fourth mile to the top of the plateau. In the lower 
part of the section while crossing the Chattahoochee limestone the road runs 
in a direction northwest td southeast. At the top of this first part of the hill 
the road turns almost at a right angle to the northeast, again turning east as 
the top of the last hill is reached. 
Thickness of stratum. 
12. Rich red sand containing, especially toward the base, an abundance 
of siliceous pebbles, light colored or stained brown by iron. 
The sand becomes coarser toward the bottom. Feeble cross- 
bedding and stratification is seen. A layer of iron concretions 
occurs 13 feet from the base, or 15 feet from the top 28 feet 
11. Pinkish and purple sandy clays in horizontal position : 9 feet 
10. Covered and sloping 42 feet 
9. Marly limestone : : 4 feet 
8. Covered and sloping 14 feet 
7. Light colored clayey limestone, with clay inclusions near the top 26^ feet 
6. Sandy pale yellow limestone 4 feet 
5. Lime clay stratum similar in character to that found at Aspalaga 
Bluff, the top of which in that section lies at the north end of 
the bluff 19^4 feet above the river at same stage of water 3^4 feet 
4. Clayey limestone, alternating ledges of harder material with lime 
clay strata intervening 1654 feet 
3. Stratum of greenish calcium carbonate crystals imbedded in a soft 
marly matrix 1 foot 
2. White soft clayey limestone with ledges of harder, more compact 
limestone. Some shells as casts and also occasional manatee 
ribs are found in this part of the section 12 feet 
1. Covered from the river to the base of the section a distance of 
about one-fifth mile , 21^4 feet 
SECTION AT ASPALAGA BLUFF. 
Aspalaga Bluff is seven miles in a direct line from the north boundary of 
the State and is the first point in Florida at which the river channel strikes 
the east bluff. The following section was made near the north end of that 
part of the bluff facing the river. A continuous exposure is not found in any 
direct line of sectioning. In order to* determine thickness of strata it is often 
necessary to transfer the level for short distances along the side of the bluff. 
Thickness of stratum. 
12. Covered in the line of sectioning to the top of the bluff about one- 
fourth mile back from the river, about 60 feet 
