728 D. WHITE LATE THEORIES REGARDING THE ORIGIN OF OIL 



cosmic theorv,- Ross' solfataric gas hypothesis,^ or Kizhner's theory* of 

 the contact of hydrogen with red-hot carhonized iron in the depths of the 

 earth. This tlieory, though apparently of independent origin, is antici- 

 pated in some respects by the synthetic experiments by Steiger. The 

 laboratory synthesis of hydrocarbons is the subject of an excellent brief 

 discnssion by Bacon and Hamor. Chemically all are possible; geologic- 

 ally they are, in brief, totally incompatible with obvious facts, and there- 

 fore, from present standpoints, impossible. The adherents to the in- 

 organic origin are nearly all chemists. Practically all geologists are in 

 opposition. The latest blow to the inorganic origin has been struck by 

 a chemist distinguished for his researches in petroleum. Mabery points 

 out^ that the nitrogen derivatives which are jn-esent in most, if not all, 

 petroleums are conclusive evidence of the inorganic origin of the oils, 

 since they can have been derived only from matter of organic origin. 



Modern Theory of Origin 



On account of both the geographic and the stratigraphic distribution 

 of the petroleums, their optical characteristics, and the conditions under 

 which the organic mother detritus seems in most cases to have been de- 

 posited, it is now generally ])elieved that petroleum is derived for the 

 most part from plants of low orders, yielding waxy, fatty, gelatinous, or 

 resinous products, with which is mingled more or less animal matter, 

 possibly associated in plankton. However, it is thought by many that 

 animal organisms, such as foraminifera, may have been the principal 

 source, at least in some instances. This plant and animal matter was de- 

 posited as organic detritus or debris in muds and slimes, including the 

 '^sapropel'^ of Potonie ; in the bottoms of ponds, lakes, estuaries, and under 

 favorable conditions, such especially as stagnation, on the sea bottom; 

 then, after the extinction of the destructive aerobic bacteria, it was long 

 subjected to slow deoxidizing transformation by the anaerobic microbes. 

 The work of the latter, which is most commonly evident through the gen- 

 eration of methane, may, unless arrested by complete elimination of the 

 oxygen or by the production of toxin as a result of their own processes, 

 persist for unknown but variable periods in the buried matter, of which 

 much at least becomes chemically transformed under their influence. 



Effective arguments for the prominent place taken by low plant orders 

 in the ingredient matter of the mother rocks of petroleum are found in 

 the microscopical examination of cannels, bogheads, oil shales, etcetera, 



BuU. Soc. Imp. Nat. Moscow, vol. 3, 1890, p. 720. 



Kept. Brit. Assoc, 1891, p. 639 ; Chem. News, vol. 64, 1891, p. 191. 



.Tour. Russ. Phys.-Chem. Soc, vol. 46, 1914, p. 1428. 



Econ. Geology, vol. 11, no. 6, 1916, p. 513. 



