PRELIMINARY REMARKS ON THE GEOLOGY OF THE BAHAMAS, 



WITH SPECIAL REFERENCE TO THE ORIGIN OF THE 



BAHAMAN AND FLORIDIAN OOLITES.^ 



By Thomas Wayland Vaughan. 



At Doctor Mayer's request the following preliminary statement on 

 certain aspects of Bahaman geology and on the origin of the Bahaman and 

 Floridian oolites is submitted as a companion paper to that of Mr. Drew, 

 whose untimely death is both a source of great sorrow to his friends and a 

 heavy loss to science. As Drew's investigations have proven an essential 

 step in the solution of the problem of the origin of the extensive oolitic lime- 

 stone formations of Florida and the Bahamas, it is fitting that an account of 

 the processes by which they originate should accompany his posthumous 

 memoir. Although the investigation of the rock specimens and bottom 

 samples obtained in the Bahamas and Florida from April to July 1 912 is 

 not complete, certain definite and some tentative conclusions have been 

 reached which may here be appropriately stated. 



The Bahama Islands and their accompanying shoals occupy a triangular 

 area which lies east of Florida and north of the islands of Cuba and Haiti. 

 The northwest corner of the triangle is in latitude 27° 35' N., longitude 

 79° 2' W., about 40 miles north of Jupiter Inlet on the Florida coast. The 

 southeast corner is Turks Islands, north of Haiti, in latitude 21° 20' N. 

 and longitude 71° 5' W. The western side is a nearly north-and-south line 

 from Little Bahama Bank to about latitude 25° 30', whence the boundary 

 bends into a south-of-east direction. The islands either occur on one of 

 two large banks, the Little Bahama and the Great Bahama Banks, or they 

 rise to the southeast of the latter bank as isolated eminences separated by 

 water as much as 1,000 fathoms in depth. 



The shoalest water in the bottom of New Providence Channel between 

 Little and Great Bahama Banks is 253 fathoms in depth ; that in the Straits 

 of Florida, between the former bank and the Florida coast, off Jupiter Inlet, 

 is 341 fathoms deep; between the latter bank and Florida the depth is 422 

 fathoms. The Great Bahama Bank is separated from Cuba by the Old 

 Bahama Channel, which ranges from 276 to 296 fathoms in depth. This 

 bank is indented by two bodies of deep water. The first of these, theTongue 



1 The investigations, the results of which are here presented, were conducted under the joint auspices of 

 the Department of Marine Biology of the Carnegie Institution of Washington and the United States Geological 

 Survey The former organization furnished opportunities for field work, while the latter authorized the prose- 

 cution of the investigation as a part of my official duties, and furnished facilities for laboratory studies in 

 Washington. 



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