io8 PRINCIPLES OF STRATIGRAPHY 



and then rises abruptly in the chain of Lu-Tschu Islands, which 

 bound it on the southeast. Its littoral belt occupies more than two- 

 thirds the width of the sea on the west or continental side, but is 

 extremely narrow on the east or oceanic side, where the islands 

 rise abruptly. The maximum depth within the chain is 914 meters. 

 Typical marginal mediterraneans are found in the Japan Sea, 3,731 

 meters ; in Okhotsk Sea, 3,370 meters ; and in Behring Sea, 5,369 

 meters — all on the east coast of Asia. The last of these is an ex- 

 ample of a mediterranean in which the rim is in large part sub- 

 merged, only islands bounding it on the south, east, and north. An 

 example of a still more extreme marginal mediterranean is the Coral 

 Sea, east of Australia, the deepest part of which descends to 4,663 

 meters, but of which the southeastern margin is largely composed 

 of submerged reefs and shoals with deep channels between. From 

 this a further step takes us to the oceanic deeps, already mentioned, 

 as the extremes in one direction, while the land-locked type leads 

 through the Black Sea type of nearly cut-off bodies to the com- 

 pletely enclosed deep continental seas or lakes, such as the Cas- 

 pian, A subordinate type is found in the Adriatic, which is a de- 

 pendent, not of an ocean, but of the Roman mediterranean. Only a 

 small part of its bottom falls below the 200-meter line, its greatest 

 depth being 1,589 meters. It is thus transitional to the epicontinen- 

 tal seas. 



It is noteworthy that marginal mediterraneans, so characteristic 

 of the western or Asiatic border of the Pacific, are wanting on the 

 eastern or American border. On the west Atlantic (east American) 

 coast we have the Caribbean and Mexican mediterraneans already 

 mentioned, and between them the smaller Yucatan basin, which de- 

 scends to 6,269 meters south of Grand Cayman Island. The ridge 

 between this and the Caribbean lies between Pedro and Rosalind 

 banks and has a maximum depth of nearly 1.300 meters. The Wind- 

 ward Canal between Haiti and Cuba has a maximum depth of 1,284 

 meters and the Mona passage between Porto Rico and Haiti, one of 

 the entrances to the Caribbean, only 583 meters, though the main 

 entrance, the Anegada Straits, between the Virgin Islands and Som- 

 brero in the Lesser Antilles, is less than 2,000 meters, while the 

 greatest depth of the Caribbean is 5,201 meters. The Florida Canal, 

 the exit from the Mexican mediterranean, has a maximum depth of 

 803 meters. On the northern Atlantic we have Bailfin Bay (5,249 

 meters), which, though also open to the Arctic Ocean, has its 

 broader connection with the North Atlantic. On the East Atlantic 

 coast no mediterraneans except the Roman, with its dependents the 

 Adriatic and Black seas, occur, but epicontinental seas abound. 



