hill: geology of Jamaica. 



35 



distance to the west tliereof. At Port Maria the same plain is visible 

 both on the mainland and on Cabaretta Island, shown in Plate XIII. 

 Fig. 1, which has been but lately severed from it. This level is largely, 

 if not entirely, composed of the old Pliocene marginal sediments of the 

 sea which have been raised to their present position by epeirogenic 

 uplift. 



S£A LSrSL 



Figure 12. Elevated Reefs, North Co.ast. 



The Elevated Reef Levels. — These are more fully described in a later 

 chapter. •"■ They are three in number, approximating 15, 25, and 60 feet 

 above the sea, respectively. Only the lowest of these has any consider- 

 able extent. These benches are usually composed of single strata, no- 

 where over 50 feet in thickness, made up of coral heads in situ and 



Figure 13. Elevated Reefs, Northeast Point. 



interstitial debris of the reefs, as they originally grew in the water, upon 

 shallow submerged benches or marginal platforms, similar to those upon 

 which they are now growing around the island, and which have since 

 been brought into their present position by elevation of the island. 



^ These are more fully discussed in the geologic portion of this paper. 



