112 PRINCIPLES OF STRATIGRAPHY 



Barents Sea, lying between Spitzbergen on the west, Nova Zembla 

 on the east, the North European coast on the south, and nearly- 

 closed on the north by the island group of Franz Josef Land. It 

 has some depths as great as 370 meters, but is shallow for the most 

 part, so that it is best classed as an epicontinental sea. 



The North Sea and the Irish Sea are examples of marginal 

 epicontinental seas on the North Atlantic border. The former is 

 for the most part less than 100 meters deep, but has some depths as 

 great as 187 meters off the Orkneys, while the latter has a maximum 

 depth of 124 meters, much of its bottom lying between 50 and 100 

 meters. Tfie English Channel is an extreme case, approaching the 

 dependent type ; still it has a few deep holes descending to a 

 maximum of 172 meters north of the Channel Isles. Its opening 

 into the great North Sea at Dover Straits gives it, however, a 

 peculiarity not possessed by other marginal bodies of this kind. In 

 the South Pacific the Tasmanian Sea, between Australia and Tas- 

 mania, may be classed as a shallow, flat-bottomed, rather open epi- 

 continental sea of the marginal type. Its greatest reported depth 

 is 88 meters. 



B. Dependent Seas — Funnel Seas. 



A typical example of a dependent sea is found in the Gulf of 

 California, between the Peninsula of Lower California and Mexico. 

 The floor of this water body descends from zero at the head to 

 2,600 meters below sea-level at the mo:j:th, the descent being a 

 regular one. At the same time the channel v^^idens so that the form 

 is that of a narrow funnel split lengthwise. This Funnel Sea 

 (TricJiter See, mare tuyau), as it may be called, will never become 

 distinct, no matter how much the surface of the ocean is lowered; 

 it will simply be shortened until, when the level has been lowered 

 2,600 meters, it becomes extinct. In form it resembles a broad 

 river valley ; indeed, if it were shorter and shallower it might be 

 regarded as the estuary of the Colorado River, which enters its 

 head. 



An example of a broader funnel sea is found in the Bay of 

 Biscay, which descends to near 5,000 meters at the mouth. Here a 

 few deeper depressions may occur inside of the mouth, but the form 

 is in all essentials that of a funnel sea. 



The Bay of Fundy on the Atlantic is a shallow funnel sea, not 

 descending below 200 meters at the mouth. It may be regarded as 

 the littoral type of the narrow funnel seas, just as the Californian 

 Sea may be regarded as the littoral-abyssal type of the same class. 



