28 



PRICE 



Figure 17 : Companion chart for the eastern half of the Gulf. The same longitudinal zones 

 are present. We have discussed them in connection with the diagram maps of the Gulf (Figs. 

 13 and 15). The submerged karst plain of Florida is slightly modified by recent deposition in 

 the karst depression and by erosion which is partly organic. 



As discovered by Howard Gould in his dredging, the shelf of the beach-bordered central 

 Florida coast is covered by a crust or spongy zone, perhaps a foot or two thick in places, 

 formed by the calcareous tests of all kinds of organisms. Gould hoped to obtain samples of 

 the rock but could get only tiny chips of black limestone which were dredged up with large '" 



amounts of the spongy crust. 



The Florida Keys stand on a reef platform like that on the Campeche Banks off Yucatan. 



Off western Florida, in the low-energy zones, are a range of limestone hills, low ridges, 

 and dome-shaped mounds. Gould concludes from samples that the mounds and low south- 

 pointing ridges along the 30-40 fathom contours are probably algal reefs. Rock ledges are re- 

 ported by divers. The ledges overhand slightly at the east. 



Much narrower and much steeper submerged deltaic bodies than those in the west are 

 found east of the Mississippi delta. These eastern bodies are less effective as energy reduc- 

 ing obstacles than those to the west. The navigation charts are not detailed enough for a satis- 

 factory study of the surfaces of these obstacles. They seem to be consistently cross-gullied 



■\\ aKMtUCT » 



DYNAMIC ENVIRONMENTS p, 



OF CONTINENTAL J 



SHELF \ 



GULF Of MEXICO f 



W.Antiilronfl Prict F^tnory 1954 ''- 



NE SHEET 



«! 



__J! 



Figure 17. 



