46 NOTES ON THE GEOLOGY OF THE BAHAMAS 



The Formation of the Bahamas 



As previously stated, the islands lie on the eastern and northern 

 edges of the Great and Little Bahama Banks. The only exceptions 

 axe Great Bahama Island, the Biminis, and some others that are 

 exceedingly small. 



As I have visited only New Providence and Andros, I hesitate to 

 do more than suggest that the other islands of the banks have been 

 formed by the action of the waves and wind in the same manner as the 

 cays near Nassau. 



A visit to the other islands of the group would be well repaid, for 

 some of them, as San Salvador, Rum Cay, and Inagua, have appar- 

 ently been formed in a different manner from those on the Great Bank. 

 And it is interesting to note that Dr. Bryant ^ describes Inagua as a 

 raised atoll. And Crooked Island and Acklin together resemble in a 

 remarkable manner the shape of the Keeling Atoll.^ Should these be 

 proved portions of an elevated atoll, it would be interesting, as they 

 would be only exceeded in size by the atolls of the Maldiva Archipelago, 

 which are the largest known.^ The islands of the Caicos Bank also 

 resemble the form of an old atoll, and the bank is still larger than that 

 on which Crooked and Acklin islands are situated. 



In conclusion, it is interesting to note that Darwin and Professor 

 Dana, although they never visited the Bahamas, have, from a study of 

 the charts, come to diametrically opposite conclusions in regard to 

 the evidence they present of elevation or subsidence. Professor Dana 

 states* that ''the Bahamas show by their form and position that they 

 cover a submerged land of large area," and that " the long line of reefs 

 and the Florida cays trending away from the land of southern Florida 

 are evidence that this Florida region participated, though to a less 

 extent than the Bahamas. ... * Thus the size of the islands, as well 

 as the existence of coral banks and also the blankness of the ocean 

 beyond, all appear to bear evidence to a great subsidence." 



Darwin, on the contrary, says:^ proofs of elevation within recent 

 Tertiary periods abound over nearly the whole area of the West 



^ Proc. Bost. Soc. Nat. Hist., Vol. XI, 1866, p. 63. 



2 Darwin, "Coral Reefs," 3d ed., PI. I, Fig. 10. 



3 Dana, "Corals and Coral Islands," p. 190. 

 * "Corals and Coral Inlands," p. 368. 



6 "Coral Reefs," 3d ed., p. 268. 



