26 



The Evolution of the Universe 



Fig. 11. Polar wandering paths postulated from pre-Cambrian to the present 

 on the basis of rock magnetism. A, pre-Cambrian of the United States; Pre-£, 

 pre-Cambrian of Great Britain; e, Cambrian; O, Ordovician; S, Silurian; 

 D, Devonian; C, Cp, Cambrian or Pennsylvanian; P, Permian; Tr, Triassic; 

 K, Cretaceous; E, Eocene; M, Miocene. Solid lines, paths in Northern Hemi- 

 sphere; broken lines, paths in Southern Hemisphere. Thick line, paths inferred 

 from British rocks; thin line, paths inferred from American rocks. (After 

 Runcorn.) 



surface gases and that the present oceans and atmosphere are the 

 result of gases escaping from the earth's interior (Rubey, 1955). 

 Rubey believes that a dense primitive atmosphere would have had 

 geological effects not now found on the earth and that several 



