46 FLORIDA GEOLOGICAL SURVEY SIXTH ANNUAL REPORT, 



un the Caloosahatchee River probably extend beneath the Ever- 

 glades to the east. The next older deposits, the Miocene, since they 

 are found exposed along the eastern flank of northern Florida and 

 are believed to have been recognized in deep well drillings on the 

 Atlantic coast, are likewise to be expected underlying southern 

 Florida. The Oligocene deposits, which are yet older than the 

 Miocene, and are extensively exposed to the north and west, may 

 confidently be expected underlying the Elverglades, although at a 

 considerable depth. The older of the Oligocene formations, the 

 Vicksburg limestone, has in fact been recognized in well drillings 

 west, east and south of the Everglades. At Fort Meade, about 

 100 miles northwest of Lake Okeechobee, the Vicksburg limestone 

 lies at a depth of 410 feet; at Palm Beach on the east, it is found 

 at about 900 feet from the surface, while at Key West, about 100 

 miles southwest of the Everglades, this formation is buried to a 

 depth of 700 feet. The Vicksburg limestone in particular is men- 

 tioned as it is the great water reservoir of the State, from which 

 most of the large wells of peninsular Florida draw their supply. 

 While its depth within the Everglades has not yet been deter- 

 mined, it is sure to be found there, and when drilled into it may 

 confidently be expected to supply the abundant flow of water that 

 is obtained from it elsewhere in the State. 



From the account that has been given it will be seen that the 

 formations of the Everglades consist of limestones, marls and sand 

 strata, which in general dip to the east. It will also be seen that 

 tlie surface limestones present considerable variation among them- 

 selves and are well suited to the general uses of a rapidly devel- 

 oping country, while from the deeper formations will be obtained 

 an abundant water supply for domestic and industrial purposes. 



MATERIALS FOR MORTAR AND CONCRETE. 



^lORTAR. 



Sands, either siliceous or calcareous, suitable for mortar, occur 

 in practically all parts of Florida. The size Of the sand grains has 

 a bearing on its qualities as a mortar sand. Coarse sand has a 

 smaller surface area in proportion to volume than has fine sand. 

 In order to obtain the best results each grain of sand in a mortar 

 should be thoroughly coated with cement, and it appears prob- 

 able that the coarse sand owing to its smaller proportion of sur- 



