122 
FLORIDA STATE GEOLOGICAL SURVEY. 
ing to statements made by Mr. James R. Harvey, this shell marl ex¬ 
tends southward along the Ocklocknee River nearly twelve miles. At 
Jackson Bluff, about one mile southwest of Bloxham, the Chocta- 
whatchee marl has a thickness of eight or ten feet. (See secs., p, 114). 
This locality was described by Dali 1 in 1894 and in 1900 the locality 
was visited by Vaughan 2 who collected the fossils listed by Dali 3 in 
his discussion of the Florida Miocene. 
Section at Jackson's Bluff . 
Superficial sands ........ 5 feet. 
Bluish marl with Mactra congest a, Choctawhatchee..... 8 feet 
Gray marly bed, with oysters and Pecten'. ... 22 feet. 
Total thickness ........ 35 feet. 
Vaughan also collected from a yellowish sand representing a 
slightly higher stratum of the same bluff in the N. E. of Sec. 20, 
T. 1 S., R. 4 W., and he reports the occurrence of similar fossils in 
Sections 21 and 30, T. 1 S., R. 4 W. 
The presence of Pecten madisonius in a collection of Pliocene fos¬ 
sils from the banks of the St. Johns River one-fourth mile below 
Nashua, Putnam County, suggests that Miocene may occur at that 
locality. The collection was made from a shell marl forming a bluff 
which rises about three feet above the river. 
Samples of marl from a well at DeLand were examined by Dr. 
Vaughan and found to contain Pecten type of madisonius and Chi one 
type of cancellata. From the presence of the madisonius type of 
Pecten the marl is believed to be Miocene. 
Species of Pecten eboreus Conrad and Pecten gibbits Linn., to¬ 
gether with Ostrea haitiensis Sowerby were also found about one mile 
above Caloosa on the Caloosahatchee River. The presence of these 
fossils is believed to indicate that the beds are Miocene; but this con¬ 
clusion is held subject to revision in case subsequent investigations 
should result in the finding of larger collections which belong to some 
other period. This locality is of special interest because heretofore 
no Miocene has been reported so far south on the Gulf coast of the 
State. 
1 Dali, Wm. H., and Stanley-Brown, Joseph. Cenozoic Geology along the 
Apalachicola River. Gepl. Soc. Am., Bull. vol. v, 1894, p. 158. 
2 Vaughan, T. Wayland. Unpublished notes. 
3 Dali, Wm. H., Wag. Free Inst. Sci. Trans., vol. 3, pt. 6, 1903, pp. 1596-98. 
