158 Papers from the Marine Biological Laboratory at Tortugas. 



surface distribution of Miocene deposits is from a locality about 9 miles 

 southwest of Tallahassee westward along the western extension of the 

 State. This is a narrow strip, 6 to 12 miles wide, bounded on the north 

 by the Apalachicola Group, on the south by Pleistocene deposits, except 

 at the eastern end of the area where the Miocene has been eroded and 

 the Apalachicola is exposed southwest of Wakulla River. No Miocene 

 outcrops are known on the base of the Peninsula between Tallahassee 

 and Trail Ridge, which forms the divide between the headwaters of 

 Santa Fe River and the St. John's River drainage. Miocene sediments 

 compose Trail Ridge whence they extend eastward to Jacksonville and 

 St. Augustine. The Miocene Sea extended northward, Miocene fossil- 

 iferous deposits being known at Brunswick, Doctortown, on the Altamaha 

 River, and at Porter's landing in Effingham County, on the Savannah 

 River, in Georgia. South of the latitude of St. Augustine the Miocene 

 is usually overlain by more recent deposits, and few exposures have 

 been reported. The reported localities are given in the following notes: 



Dall * reports Pecten jeffersonius and Carditamera arata from Pres- 

 ton sink, 3 miles north of Waldo, Alachua County, a locality at the south- 

 ern end of Trail Ridge; and Venus rileyi, V. permagna, and Area linmla 

 at a depth of 208 feet in a well at St. Augustine. The presence of Pecten 

 madisonius in a collection of Pliocene fossils from the banks of St. John's 

 River, a quarter of a mile below Nashua, Putnam County, indicates 

 Miocene at that locality.^ Pecten of the type of madisonius, and a Chione 

 of the type of cancellata were obtained from a well at De Land, the former 

 suggesting Miocene as the age of the bed.^ 



E. A. Smith obtained from Rock Springs near Zellwood, Orange 

 County, Pecten madisonius, Venus alveata, Venericardia granulata, Car-. 

 ditamera arata, and Mytiloconcka incurva identified by Heilprin.^ Heil- 

 prin reports from Rocky BlufiE on the Manatee River, 5 or 6 miles above 

 Braidentown, Area incongrua, Perna maxillata, Pecten jeffersonius, P. 

 madisonius, and Venus alveata.^ Dall states that "it is probably from 

 more westerly submarine strata belonging to this series of beds that was 

 derived the Ecphora collected by Doctor Stearns in 1868-69 on the 

 beach of Long Key."^ Miocene fossils, Pecten jeffersonius and Pecten 

 madisonius, were also obtained by Professor Heilprin on Phillips Creek, 

 which flows into Little Sarasota Bay.® 



No Miocene outcrops occur between the Vicksburg and Apalachi- 

 cola areas of the Peninsula and the west coast. 



Well-borings show that Miocene is present beneath later formations 

 even as far south as the keys. The records of the Palm Beach well given 

 on page 1 27 of this paper show Miocene between 800 and 915 feet and per- 

 haps at 400 feet beneath the surface. The deep well at Marathon on 

 Key Vaca (see page 128) revealed probably Miocene fossils between 375, 



' U. S. Geol. Siirv., Bull. 84, pp. 124, 125, 1892. 



^ Matson and Clapp, Florida Geol. Surv., 2d Ann. Report, p. 122, 1910. 



^ Am. Jour. Sci., 3d ser., vol. xxi, p. 302, 1881. 



* Wagner Free Inst. Science, Trans., vol. i, p. 13, 1887. 



^U. S. Geol. Surv., Bull. 84, p. 125, 1892. 



^ Dall, op. cit., jj. 126. 



