Some Considerations about the Primaeval 

 State of the Earth 



V. G. FESENKOV 



Institute of Astrophysics, the Academy of Sciences Kazakh SSR, Alma-Ata, U.S.S.R. 



The solution of many problems of geology, geochemistry, biology, and par- 

 ticularly the basic problem of the origin and development of life, requires a 

 knowledge of the conditions that characterized the physical state of the Earth 

 during the earHest periods following its formation. To describe these conditions 

 in the Hght of a definite cosmogonie hypothesis would be misleading, since the 

 problem of cosmogony cannot be as yet considered as fully solved. On the 

 contrary, the solution of this problem should follow from a consideration of 

 all relevant facts that are capable of receiving, as far as possible, a unique 

 interpretation. 



From a consideration of such facts one may draw certain conclusions relating 

 to the process of formation and development of the Earth. 



The first conclusion is that during its formation the Earth lost a considerable 

 part of its initial mass. It may be assumed that the Earth of to-day is but a 

 nucleus of the primary protoplanetary condensation that consists of the heavier 

 elements and their oxygen compounds [i]. This conclusion is supported by the 

 fact that the elements most frequently met with in the Universe, in the stars 

 and in the sun, and which for this reason should also be abundant in the primaeval 

 medium that gave birth to the planets, are nearly totally absent in the present- 

 day atmosphere of the Earth. Conspicuous is the neghgible quantity of the inert 

 gases (including xenon and crypton) in our atmosphere, whereas their abundance 

 in the universe is many times greater [2]. 



The question may arise as to the process that could promote the escape of the 

 primordial atmosphere of the Earth, including even such heavy gases as krypton 

 and xenon. It is quite evident that if each gas escaped individually in accordance 

 with its atomic weight, these very abundant heavy gases would have remained 

 on the Earth in practically their original abundance. It must therefore be con- 

 cluded that this process of dissipation is determined chiefly by the most abundant 

 and the Hghtest element, namely by hydrogen which constituted the greater 

 part of the primitive Earth's mass. As hydrogen escapes into space it takes with 

 it all the insignificant impurities, excessively high temperatures not being 

 required for this purpose. If we assume that the initial abundance of hydrogen 

 corresponded, to a certain extent, to its abundance in the Universe, the inevitable 

 conclusion is that there remains from the primitive Earth only a small percentage 

 of its original mass. A further proof of the primitive Earth's losing a consider- 

 able portion of its mass is the very fact of the existence of the Moon. There can 

 be no doubt that the Earth-Moon system occupies a special place in our solar 



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