CONTENTS. 



Introduction 105 



Topography of the Floridian Plateau 107 



Relation of the loo-fathom curve to the present land surface and to 



greater depths 107 



The lo-fathom curve 108 



The reefs -. 109 



The Hawk Channel no 



The keys no 



Bays and sounds behind the keys in 



Relief of the mainland 112 



Marine bottom deposits forming in the bays and sounds behind the keys 1 14 



Biscayne Bay 116 



Between Old Rhodes Bank and Carysfort Light 117 



Card Sound 117 



Barnes Sound 117 



Blackwater Sound 117 



Hoodoo Sound 117 



Florida Bay 117 



Gun and Cat Keys, Bahamas 119 



Summary of data on the material of the deposits 119 



Report on examination of material from the sea-bottom between Miami 



and Key West, by George Charlton Matson 120 



Sources of material 126 



Silica 126 



Geologic distribution of siliceous sand in Florida 127 



Calcium carbonate 129 



Calcium carbonate of inorganic origin 130 



Pleistocene limestone of southern Florida 130 



Topography of southern Florida 131 



Vegetation of southern Florida 131 



Drainage and rainfall of southern Florida 132 



Chemical denudation 133 



Precipitation of chemically dissolved calcium carbonate.. . . 135 



White-water periods 136 



Effect of sea-spray 136 



Calcium carbonate derived through surface erosion 136 



Calcium carbonate of organic origin 137 



Resume of sources of calcareous sediments 137 



Geologic distribution of limestone in Florida 138 



Tertiary coral reefs of the Southern United States 138 



Transporting agents of the Florida coast and their effects 140 



Constant currents 140 



Tidal currents 141 



Winds 141 



Effect of Florida countercurrent on shore topography of Florida. . . . 142 



Banks behind keys 145 



Deltas at outer ends of passages between keys 145 



Areal distribution of the geologic formations 146 



Oligocene 146 



Vicksburg Group 146 



Apalachicola Group 146 



Miocene 147 



Pliocene 147 



Pleistocene 147 



General relations of geologic boundaries in Florida 148 



Drainage lines 148 



Geologic history of the Floridian Plateau 150 



Events of Vicksburgian time 150 



The Vicksburgian submergence 150 



Depth and temperature of the waters 150 



Summary of Vicksburgian events 152 



101 



