76 R. K. EMERSON — TETRAHEDRAL EARTH : INTERCONTINENTAL SEAS 



Mississippi, adding broad areas of Secondary and Tertiary rocks. In the 

 game way Asia, is bordered by ancient rocks from Bering strait to Corea, 

 which extend in part to the shore in rias coasts and sink from its high 

 lands by great step-faults to the sea. On the north they formerly ex- 

 tended farther eastward, and are now submerged. On the western side 

 late elevation has raised the broad Tertiary seabottom which separated 

 Europe and Asia and extended the great continent to the Urals. 



Europe, the smallest continent, with the most complex structure, has 

 the Urals on the east, of the same age and character as the Appalachians 

 and the southeastern mountains of Asia, and folded Tertiary rocks toward 

 the west and south. It has lost nothing east of the Urals and gained 

 nothing beyond the old Caledonian chain on the west; and coinciding 

 herewith, there is no lateral shifting in relation to Africa. 



Moreover, the western half of Australia is unfolded tableland of 

 Archean age, and this lies due south of the Manchurian boss, and the 

 eastern area to and including New Zealand is folded land made much 

 later. There is thus no torsional motion between the two semi-conti- 

 nents — an idea suggested largely by the great curved island chain joining 

 them, which receives independent explanation. 



On the other hand, South America has grown westward, and yet the 

 whole continent is east of the middle line of the Canadian protaxis, and 

 and if such an eastward thrusting of a continental mass were anywhere 

 conceivable it would be here, where the lofty, sharply compressed Andes 

 indicate a powerful thrust, and where the recently sunken southern 

 Pacific may have furnished the force. 



Moreover, the deepest water of the Pacific is off the Asian coast, that 

 of the Atlantic off the American coast, and we have in the line of deep 

 sinkholes below the level of the sea — the Caspian and Aral — a reminis- 

 cence of the Tertiary time, when the deepest water of the Tertiary ocean 

 bordered the eastern shore of Europe. Now, the deepest sinking of the 

 oceans is not the cause of the highest mountains on the adjacent lands. 

 Indeed, no mountain chains can be correlated with those depressions. 



It had seemed possible that a different mode of the cause proposed by 

 Green might be effective at times and under most favorable circumstances, 

 at least by aiding or opposing the larger forces of contraction to produce 

 the conditions under discussion, namely, sinking of eastern and rising 

 of western coasts. A sinking sea-bottom may exert force east and west 

 as a wedge, and additional or differently directed force east by inertia. 

 Sometimes the sinking may be rapid enough so that some part of this 

 force may be effective. Land rising with some suddenness in an eastern 

 coast would lag to westward. Adjacent sea-bottom, sinking, would 

 advance to eastward. They would tend to separate. This might pro- 



