Conditions for Appearance of Life on Earth 85 



sidered as a prototype of the processes on the basis of which the vital activity of 

 the primary organisms could have taken place : 



I. C„H„, = a (H„', C„,') + CH4 t , with n' ^ "^, m' = '^^ 



2. SO4 + 2C + 2H2O -= 2HCO3 + H2S t 



The first type of reaction is carried on by anaerobic bacteria during the de- 

 composition of organic matter in water basins in conditions of a reducing chemical 

 medivmi, methane (CH4) being formed at the expense of more complex organic 

 compounds. 



The second type of reaction, i.e. desulphatization, is brought about by de- 

 sulphurizing petroleum bacteria in the presence of petroleum and water con- 

 taining SO4 ions. Petroleum bacteria, discovered by T. L. Ginzburg-Karagicheva 

 in the petroleum of the Apsheron Peninsula, and by Bastin in the Pennsylvania 

 oil (U.S.A.), are found in wells from 750 to 2760 metres deep. They breed most 

 abundantly near the under interface, where the petroleum comes in contact 

 with the waters underlying it, these waters usually being of the sulphate-chloride 

 type. It is known that the sulphates in these waters are of inorganic origin and 

 are derived partly from the salt residue in the marine sedimentary strata, and 

 partly, possibly, from mineralized waters of more abyssal genesis. The course of 

 both mentioned reactions from left to right is favoured by the fact that the 

 gaseous products (CH4, H2S) gradually rise. 



Similar conditions, in principle, could have arisen in the Archaean era at the 

 surface of lagoons or other water basins, if they were covered with a film of oil. 

 It should be noted that the oxidation of oil, which now rapidly leads to the 

 formation of resin, polymerization of bitumens, and to the transformation of 

 petroleum into asphalt, at that time did not as yet take place because of the lack 

 of oxygen. Consequently, conditions favourable for the reduction of sulphates 

 in sea or lake waters, with petroleum present, could have been maintained for a 

 considerable time. 



THE PRESENT STATE OF RESEARCH ON THE 

 INORGANIC ORIGIN OF PETROLEUM 



The pattern of the origin and development of life, outlined above, could only 

 be considered sufficiently if the sources of the large quantities of petroleum or 

 abiogenic hydrocarbons, similar to oil in chemical composition, were known. 

 The origin of petroleum has been debated for 100 years and is one of geology's 

 most controversial problems. The hypothesis of inorganic origin of petroleum 

 was highly popular in the second half of the nineteenth century, when it was 

 developed by D. I. Mendeleev, M. Berthelot, H. Moissan, E. Coste, and others. 

 But later, it seemed to have been completely abandoned. This was especially so 

 during the 1920's and 30's, when there appeared the investigations of C. D. 

 White, P. D. Trask, and others in the U.S.A., of I. M. Gubkin, G. L. Stadnikov, 

 and A. D. Arkhangelskii in the U.S.S.R., and so on [6]. 



But geologists have lately again become interested in the inorganic hypothesis. 

 This interest was roused owing to the fact that explorations in any well-studied 



