580 



GINSBURG, LLOYD, STOCKMAN AND MCCALLUM 



[chap. 2 



90 



Gulf of Batabaiio, liave a rather specific type of water circulation that might 

 be described as "bank circulation". On these shallow banks or shoal areas, 

 generally measured in tens of miles, there is frequent exchange of water with the 

 adjacent oceans by tidal currents and wind drift. Salinities are seldom far 

 above or below that of open ocean water, but temiDeratures are usually higher 

 than those of surface ocean water. 



BAHAMA BANKS 



L E C E H 



I I P6il«t8 and compo«lt« Qfoins 



I I Oolites 



10 20 30 40 90 



1 { ! ! : I 



SCALE IN NAUTICAL MILCS 



»Mi /// # //// /l ^^^^^^ 



Fig. 15. Distribution of non-skeletal sands on Great Bahama Bank. (After Newell, 1955.) 



Differences in the variety and abundance of non-skeletal particle types 

 produce distribution patterns in non-skeletal sediments similar to those found 

 in the skeletal sediments. This strongly suggests that the non-skeletal patterns 

 are also related to variations in water circulation. At present the only example 

 is the coincidence of oolith formation and strong currents (Fig. 15), but further 

 study may disclose other more subtle relationships that will jJrove to be faithful 

 records of the long-term pattern of water circulation. 



