36 FLORIDA GEOLOGICAL SURVEY I3TH ANNUAL REPORT 



PLEISTOCENE 



From the known distribution of the Pleistocene of Florida sev- 

 eral of the wells, and especially those in the southern part of the 

 state undoubtedly penetrate Pleistocene sands for some distance 

 near the surface. There are, hov/ever. no foraminifera in these 

 sands which would give a definite clue as to their age. 



PLIOCENE 



In the earlier report I thought that there was a definite develop- 

 ment of the Pliocene in the upper part of the well at Okeechobee. 

 However, a study of the foraminifera from the upper levels — 41 

 to 56 feet — shows that most of these have a Miocene relation rather 

 than a Pliocene one. Therefore, the well samples give no definite 

 information as to the distribution of the Pliocene below the surface. 



MIOCENE 



Only slight information was avail.ible at the time the previous 

 paper was written, but a detailed study 6f the foraminifera has 

 shown not only the occurrence of Miocene foraminifera in a num- 

 ber of wells, but that they have definite relations with the Miocene 

 of other regions. The accompanying table shows the distribution 

 of some, of these Miocene species ; their distribution in the Florida 

 wells and their occurrence in related areas. As the table shows, 

 ce];'tain of the levels in a number of wells are very definitely related 

 to, if not identical with the Choctawhatchee Marl of Florida. This 

 is especially marked in the well at Okeechobee, and the upper lev- 

 els of the wells at St. Augustine, Fort ]\Iyers and Marathon 

 The one species noted from the well at Jacksonville also seems 

 to have this same relation. A number of species, especially those 

 from the deeper j^arts of the wells at Fort Myers, Okeechobee 

 and Marathon, seem to be more closely related to the Miocene of 

 the Gatun formation of the Panama Canal Zone. A number of 

 species also occur in the upper Oligocene of the Panama Canal 

 Zone. The relations to the Miocene Marls of Cuba, Santo Domingo 

 and Jamaica are also indicated. 



As a result of this study, and allowing for errors in drilling, 

 the Miocene may be rather definitely located at the following 

 depths from these wells: 



