HILL: GEOLOGY OF JAMAICA. 35 
distance to the west thereof. 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. 
PO NUN BAHN 
ZN! 
au MYD 
GG 
ETA 
SEA LEVEL 
= 
77 
Ze 
din 
Figure 12. Elevated Reefs, North Coast. 
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 ¿n situ and 
Ficurn 18. Elevated Reefs, Northeast Point. 
interstitial débris 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. 
1 These are more fully discussed in the geologic portion of this paper. 
