384 EHRENFELD— JOINTING AS A FUNDAMENTAL FACTOR 



the belief is more and more growing among geologists that the 

 lithosphere is governed by processes and laws which act generally 

 to its total mass and not locally or in limited portions. Thus the 

 idea that the laws which govern the general behavior of the litho- 

 sphere cease to act or change their character in that portion of the 

 earth under the hydrosphere seems to me untenable in the first 

 place and unproven in the next. 



The " repeating patterns " of various authors^^ if they mean 

 anything at all must involve some general fundamental character 

 of the structure of the lithosphere, a character which under stresses 

 in the mass of the lithosphere would be as likely to occur under the 

 oceans as under the atmosphere contact. It is hardly reasonable 

 to attempt to dismiss these repeating patterns as due to " chance,"^* 

 they are too widespread and have been too often described and 

 identified with fundamental structures in the lithosphere. So that 

 the principle involved in repeating patterns as indicating a definite 

 characteristic of the lithosphere may be accepted certainly as a con- 

 structive working basis if not yet generally accepted as one of the 

 proven facts of geophysics. 



Applying then this principle to the mass of the lithosphere under 

 the hydrosphere it should be possible to determine from the distri- 

 bution of islands, volcanoes, coral reefs and other features, sys- 

 tems of joint control beneath the hydrosphere analogous to the 

 systems of joint control of continental surface features beneath the 

 atmosphere. In short the control of the lithosphere surface be- 

 neath the oceans by joints I regard as being of equal value and 

 importance as the control exercised by jointing in the lithosphere 

 beneath the atmosphere. 



Owing to the comparative ease with which islands on the conti- 

 nental shelves may be shown to be parts of the masses of the con- 

 tinents, and, as in the very remarkable and beautiful example 

 shown in the islands of Casco Bay in the Gulf of jNIaine, demon- 

 strated to be distributed along lines governed by jointing the prob- 

 lem becomes really complex and more difficult of proof when con- 



23 See especially Hobbs, " Repeating Patterns in the Relief and in the 

 Structure of the Land," Bull. Gcol. Soc. Amer., Vol. 22, pp. 123-176, 191 1. 

 ^* Bull. Geol. Soc. Amcr., Vol. 22, p. 717 (discussion). 



