130 SIMPLER ORGANIC SUBSTANCES 



are the hydrocarbon gases formed in the crystalline forma- 

 tions of Lake Huron in Canada and in the Ukhta formations 

 in Karelia where very large amounts of hydrocarbons have 

 been found in fissures in the volcanic formations. V. Sokolov, 

 in a personal communication, states that he has found meth- 

 ane, ethane, propane and higher hydrocarbons in volcanic 

 formations in a number of places in the Soviet Union. 



Of recent years greater and greater numbers of instances 

 of the presence of petroleum in volcanic and metamorphic 

 formations have been reported. However, as these finds are 

 very seldom of economic importance and, in most cases, only 

 consist of insignificant inclusions, petroleum geologists have 

 paid very little attention to them. Nevertheless, the finds 

 of this kind which have already been made in many countries 

 may be reckoned by hundreds.^"* In particular, liquid and 

 gaseous hydrocarbons have been found in the form of surface 

 smears and small quantities of separated material in the 

 course of deep boring in the fissures of metamorphic and 

 crystalline formations at levels to which they could hardly 

 have penetrated from the sedimentary formations. 



Thus, although petroleum extracted from sedimentary for- 

 mations shows clear signs of its biogenic origin, in the light 

 of the facts now known one cannot deny that even now the 

 abiogenic formation of hydrocarbons is taking place on the 

 Earth, albeit to a very limited extent. 



Until organisms appeared, these processes were the opera- 

 tive ones in the formation of hydrocarbons on the Earth as 

 on the other heavenly bodies. Only after the appearance of 

 life, when new and higher forms of the motion of matter 

 came into existence, did there develop new and extremely 

 highly specialised methods for the transformation of sub- 

 stances and the utilisation of energy for the synthesis of 

 organic compounds. In particular, the development of 

 photosynthesis led to the formation of systems which could 

 use the inexhaustible source of energy of sunlight for this 

 process. As a result of this an enormous amount of the 

 carbon of the surface of the Earth became involved in bio- 

 logical processes and the old, abiogenic mode of formation 

 of hydrocarbons lost its significance, as always happens in the 



