DISTILLATION VERSUS BACTERIAL ORIGIN 731 



rence of oil in the scum of small bays of the Eed Sea region and oil glob- 

 ules in the putrefaction muds and slimes of the salt marshes of Sardinia 

 and on the shores of the sound near Lund, Sweden. Definite attribution 

 of the oil to bacterial action seems first to have been made by Marrey in 

 1903.^^ In the discussion of the Burma oils, Murray Stuart,^^ whose 

 conclusions are followed by A. B. Thompson and Marcel Daly," concludes 

 that the oil generated in the decaying organic matter is carried or held 

 down in very small globules by particles of clay and detritus, and so is 

 buried in the muds until, presumably in a later period, compression 

 sliould force the oil, gas, and water into strata favorable for storage and 

 gravitational segregation. 



It will be seen that, according to this theory, petroleum originates at 

 first hand in the decaying organic debris before the organic muds, etcetera, 

 have been deeply buried or subjected to geodynamic alteration. How, 

 then, is to be explained the conversion of this primar}^ oil, which no one 

 has shown to be a typical petroleum, or even closely comparable to the 

 oils known in any region, into the various grades of petroleum found in 

 different areas ? Marcel Daly^^ proposes to explain it by chemical trans- 

 formation of the buried oils themselves under the influence of pressure, 

 with little increase of temperature, at times of diastrophic movement, the 

 importance of the time factor being emphasized. Thus, so far as it con- 

 cerns the transformation of the oil under dynamic influences to suc- 

 cessively higher ranks, the interpretation given by Daly agrees with that 

 followed by Mabery and others, including myself. A. B. Thompson, on 

 the other hand, noting that in all probability colloidal enzymes are pro- 

 duced in the course of the bacterial action, urges that these may play an 

 important part as catalysts, not only in determining the characters of the 

 oils, but in stimulating chemical reactions at times of increase in pressure 

 or temperature. He says '}^ 



". . . It may well be that the colloidal enzymes resulting from anaerobic 

 bacterial action are buried with the organic material they are acting upon, and 

 there continue their action, for there is no obvious reason why, as catalysts 

 merely, they should cease to perform their functions so long as sufficient 

 unstable organic material remains, and they themselves are not destroyed by 

 heat, or inhibited by the products of their action. . . . 



"Thus the actual hydrocarbon product would seem to depend upon (a) the 

 nature of the primary organic matter; (&) the particular character of the 

 catalytic enzymes ; ( c ) the temperature and pressure reached before complete 

 conversion; and {d), finally, the adjustment of constitution and proportions 



15 Bull. Geol. Survey Ohio (4), vol. 1, 1903, p. 313. 

 i«Rec. Geol. Survey India, vol. 40, 1910, p. 320. 

 1^ Trans. Am. Inst. Min. Eng., .July, 1916, p. 1152. 

 18 Trans. Am. Inst. Min. Eng., July, 1916. 

 1" Oil-field development, 1916, pp. 271-272. 



LIV — Bull. Geol. Soc. Am., Vol. 28, 1916 



