144 FLORIDA GEOLOGICAL SURVEY I3TH ANNUAL REPORT 



Shell mounds built up centuries ago by the aborigines are rather 

 common along the lagoons, and many of them have been excavated 

 for road-surfacing material (Fig 34). Flowing artesian wells, with 

 more or less sulphurous water, can be had anywhere, and in some 

 places the pressure is sufficient to run dynamos or other machinery. 



The ancient dunes west of the Indian River (fig. 31) are in 

 some places about 50 feet above sea-level, but this is probably due 

 largely to an uplift in comparatively recent times, for the modern 

 dunes next to the ocean are much loxyer. The outer beach in Vo- 

 lusia County is one of the most noted natural automobile race- 

 courses in the world, and speeds of 156 miles an hour have been 

 recorded there. The Indian River and other shallow salt lagoons 

 behind the barrier beaches are navigable for small vessels, and in re- 

 cent years they have been connected by dredging canals through 

 "intervening marshes and strips of sand, so that there is now an in- 

 side passage all the way up the coast to South Carolina. There 

 is practically no tide in these lagoons, on account of the inlets being 

 small and far apart. 



Fig. 29. Scene in Turnbull Hammock, a typical low hammock, about a 

 mile west of Daytona, Volusia County. By E. H. Sellards, May 21, 1910. 



Soils. The soil survey of the "Indian River area," published in 

 191 5, covers most of Merritt's Island and the neighboring barrier 

 beaches, and a little of the near-by mainland, giving a very typical 



