CONTENTS. 
Page 
Location, Area and Mineral Industries n 
Climate 12 
Vegetation \ 13 
Elevations 14 
Description of Bench Marks 15 
Elevations at Railway Stations 16 
Mineral Industries . 17 
Brickmaking Clays 17 
Fullers Earth I 17 
Limestone s 22 
Phosphate ^3 
Road Materials 24 
Water Supply 24 
Topography and Geology < 26 
Stream Valleys 26 
Steepheads i 27 
Geology 28 
Oligocene 1 < 28 
Chattahoochee Formation 28 
Surface Exposures 30 
Structure 32 
Miocene 37 
Alum Bluff Formation — 37 
Structure 39 
Choctawhatchee Formation 4 1 
Structure 43 
Miocene-Pliocene < 44 
Formation Name : , 50 
Structure *51 
Pliocene .52 
Pleistocene . — 52 
Surface Materials 52 
Geologic History , 53 
Summary of Geologic Structure • 54 
ILLUSTRATIONS. 
Fig. 1. Alum Bluff, Apalachicola River 25 
Fig. 2. Geologic Sketch Map 1 29 
Fig. 3. Contours on the Chattahoochee Formation 35 
Fig. 3. Contours on the Alum Bluff Formation 42 
Fig. 4. Exposure of Chattahoochee Limestone . 55 
Fig. 5. Sketch Map of West Florida 56 
MAP. 
Map of Area Between Apalachicola and Ocklocknee Rivers, including Profile 16 
