242 FLORIDA GEOLOGICAL SURVEY SIXTH ANNUAL REPORT. 



8. WEST FLORIDA COAST STRIP. 



(figures 58-61) 



References. Harper i (218, 265), McAtee, Sellards 3 (290-291, or 44-45), 

 and U. S. soil survey of Escambia Co., (by Griffen, Drake, Belden & Kolbe, 

 1907). 



This region extends from the mouth of the Ocklocknee River 

 west to Mississippi, in streaks and patches which are difficult to map 

 and measure accurately. Its area in Florida is probably not over 

 400 square miles. It includes most of the islands* and narrow pen- 

 insulas along the coast, and on the edge of the mainland some salt 

 and brackish marshes, and elongated belts of dry sand which seems 

 to have been heaped up by the wind long ago. Some of these old 

 dunes are almost completely surrounded by flatwoods belonging to 

 the region to be described next, but they do not seem to occur more 

 than a mile or so from tide-water (which may indicate that the po- 

 sition of the coast line has not changed much for thousands of 

 years). 



Geology and Soils — Except for a few marsh and estuarine de- 

 posits, shell mounds, and some ancient and modern peat, there is 

 nothing but Pleistocene and Recent sand near enough to the surface 

 to have any effect on soil or topography. No chemical analyses of 

 the soils seem to have been made ; but in the immediate vicinity of 

 tlie coast, say within 100 yards of the beach, the sand of the beach 

 and active dunes must contain considerable calcareous matter in the 

 form of pulverized sea-shells. Mechanical analyses of two types of 

 soil from this region have been taken from the government soil sur- 

 vey of Escambia County. The first is "Galveston sand," corre- 

 sponding to the beaches and moving dunes, and the second is "Sand- 

 hiir't corresponding to the older dunes which are no longer mov- 

 ing. The former is not cultivated at all, and the latter very little. 

 The depth to which the samples were taken is not indicated, but 



*St. James Island, in Franklin County, is an island only by accident, 

 as it were, for it is separated from the mainland only by a narrow fresh- 

 water channel (Crooked River), and the greater part of it is flatwoods, 

 indistinguishable from those of the adjacent mainland. That part of it 

 belonging to the coast strip apparently does not average more than half 

 a mile wide. The other islands are separated from the mainland by a mile 

 or more of salt water (the sounds), and are much more typical. 



tTypical sand-hills of the coastal plain occur along the fall-line and 

 along rivers and creeks, and are scarcely represented in Florida. 



