FME
"350
A FALLING WATER HILL A'
.300
MWLE
 KU
-250
. _W= G _.- -. FALLING
200... --- WATER
 -- --- -- . ... :--SIN K
Not es-o utheast, , geolog' cros secI P! Mtin hrug Falling', Water Hill,'.,..
;A N E L1 &% I A_ I I I
. . ..WAN. .. . .
1 01 1 1 1 1 1T ,.49 12 FT .
Northwest-southeast geologic cross section through Failing Water Hill.
Immediately overlying the Suwannee Umestone is a thinner and much younger limestone called the Chattahoochee Formation. This formation formed in a shallow sea during the Miocene Epoch, about 20 million years ago. The Chattahoochee Formation contains typical marine fossil shells such as pectens and oysters. Approximately 30 feet of Chattahoochee Formation. is exposed in the sides of Falling Water Sink, above the Suwannee Limestone.
In much of Falling Water Hill north of the sink, a series of younger, Middle and Upper Miocene marine and deltaic sediments, called the Alum Bluff Group, overlie the Chattahoochee Formation. Locally, the Alum Bluff Group is comprised of unfossiliferous, green, clayey siltstone, attaining a thickness of about 50 feet under the highest part of the hill. Because of their elevationally higher position, these sediments do not occur in the walls of Falling Water Sink.
Capping Falling-Water Hill and forming the uppermost sediments in the sink are a series of undifferentiated sands and clayey sands. These deposits represent river delta and marine sediments laid down during the last 5 million years.