PHYSIOGRAPHY AND GEOLOGY OF THE 

 BAHAMA ISLANDS 



BY 



GEORGE BURBANK SHATTUCK, Ph.D., 



Associate Professor of Physiographic Geology in the Johns Ilophins University, 



AND 



BENJAMIN LeROY MILLER, Ph. D., 



Associate in Geology in Bryn Mawr College. 



INTRODUCTION. 



Along the northeastern margin of the West Indies, extending from 

 sonthern Florida to eastern Haiti, is a group of three thousand or more low 

 islands, keys, rocks and banks, to which the name Bahama Islands has been given. 

 Most of these islands are small ; many of them are nothing more than rocks or 

 sand-bores, but they are so scattered that the archipelago as a whole, including 

 the submerged banks in the extreme south, extends from 'i'i° 30' to 19° 50', 

 north latitude and from 68° 45' to 80° 35', west longitude. In other words, 

 the Bahama Islands occupy a • region nearly as extensive as Great 

 Britain, and if superimposed on the surface of the United States they would 

 extend from New York southward to Atlanta, and in their widest part fi'om 

 Cape Hatteras, -w'estward to New Bern, in the heart of the Alleghany moun- 

 tains, in Avestern Virginia. 



As the archipelago is separated into a northern and southern half by the 

 Tropic of Cancer, which crosses it almost exactly in the middle, the climate is 

 practically tropical throughout. • The eastern margin of the Islands is washed 

 by breakers wliieh roll in unchecked from the broad sui-faee of the Atlantic 

 Ocean, while the western edge is swept by the Gulf Stream as it flows northward 

 through the Straits of Florida. The Islands also lie in the region of the West 

 Indian hurricanes and have been repeatedly swept by terrific cyclones which 

 have proved important geologic agents both of deposition and erosion. 



When considered from a geological point of view, the Bahamas afford an 

 interesting studv, in that they are composed almost entirely of debris derived 



