84 B. K. EMERSON — TETRAHEDRAL EARTH: INTERCONTINENTAL SEAS 



ening given by Van Hise* (omitting those due to tidal retardation and 

 noting that the reserves of all these forces had probably been exhausted 

 during the post-Carboniferous revolution), namely, (a) some fraction of 

 the diminished result of secular cooling admitted above to he unimpor- 

 tant; (/>) cementation, and (c) escape of lava and gases. Their probable 

 amount of accumulation in the Mesozoic seems insufficient to explain 

 the enormous amount and the peculiar localization of the above Tertiary 

 deformation. 



Thus the effects of tidal retardation, reserved above, seem a welcome 

 addition to the means of explanation of the crowded equatorial chains 

 in question. 



3. It is significant that Dutton, den}nng the efficacy of shrinkage, ad- 

 vances an hypothesis of mountain-making by horizontal flowage at the 

 expense of a somewhat forced hypothesis to explain a potential slope 

 along which the movement may take place. Great masses of sediment 

 are transferred from land to adjacent sea-bottom. " The result is a true 

 viscous flow of the loaded littoral inward " and upward " upon the un- 

 loaded continent.' 1 f 



Sir John Mumy, in a presidential address before the Section of Geog- 

 raphy of the British Association, has adopted and extended this theory.J 



The subcrust (tectosphere or melted layer) of the loaded margin becomes 

 more solid by increased pressure. The subcrust of the unloaded land 

 becomes viscous by relief of pressure. " Deep-seated portions of the 

 terrigenous deposits are slowly carried toward, over, or underneath the 

 submerged land." These newly formed terrigenous shore deposits had 

 become by decomposition and sorting highly silicious and lighter, and 

 by many repetitions of this process are carried from the shores into the 

 interior of the continents by a kind of arenaceous diffusion, making the 

 latter more silicious and lighter. 



4. If we review again the series of paleographical maps (plates 10 and 

 11, page 70) we shall see that, while the present equator has never been 

 emphasized as a line of importance in the ancient geography of the earth, 

 the Mediterranean zone was marked out in very earty times. From the 

 Paleozoic era to the present, one of the most persistent features shown 

 on these maps is the continuous band of water which has occupied the 



korper. Ann. d. Phys. u. Chem. 2, vol. v, pp. 405, 553; vol. vi, p. 135; vol. vii, p. 304; vol. viii, p 

 157.) 



The theory has been popularized by Zoppritz (Ver. d. deutsch. Geographen Tages, 1882, p. 15), and 

 accepted by Gunther (Lehrbuch d. Geophysik, vol. i, 1884, p. 319). It demands a vastly greater 

 central temperature and gravity, and would introduce an unknown coefficient of contraction 

 and a cooling by convection, and permit an indeterminable surface contraction. 



♦ Journal of Geology, vol. vi, 1898, p. 10. 



f Greater problems of physical geology: Bull. Phil. Soc. Washington, vol. xl, p. 60. 



X Nature, vol. lx, 1899, p. 525. 



