116 GENESIS OF NATURAL GAS AND PETROLEUM. [Feb. 5, 



ON THE GENESIS OF NATURAL GAS AND 

 PETROLEUM. 



BY FRANCIS C. PHILLIPS. 



{Read February 5, 1897.) 



If it were possible to demonstrate that the original source of 

 petroleum and natural gas is to be looked for in the rock strata in 

 which they are now found to occur, an important advance could be 

 made towards the establishment of a satisfactory hypothesis to 

 account for the genesis of these hydrocarbons in nature. 



It has often been supposed that the relationship of the hydro- 

 carbons to the rocks in which they occur is of an intimate kind, 

 and that the geological record should supply all the data upon 

 which a conclusion as to the origin of gas and oil is to be based. 

 It does not necessarily follow, however, that they are products of 

 Devonian or Silurian time because of their association with certain 

 sandstones, limestones or shales. 



The presence of a gaseous or liquid hydrocarbon in a particular 

 rock is perhaps due to the fact that the region of this rock, on 

 account of its open texture, has been one of least resistance to the 

 movement of a fluid under pressure. It is possible that gas and 

 petroleum may have invaded the Devonian strata from greater 

 depths and that their present position is wholly due to the pressure 

 to which they have at some former period been subjected. 



Other circumstances may have been factors in determining their 

 present location. An abundance of subterranean water may have 

 caused a transfer to a higher level. Differences of temperature 

 might involve a partial fractionation or distillation and removal to 

 distant regions. Hydrocarbons of different character and from 

 different sources might become mingled and thus intrinsic signs of 

 different modes of origin be obliterated. In view of these inherent 

 difficulties, which impede a solution as viewed from the geological 

 standpoint, the question seems to resolve itself for the present into 

 a broader but less definite one which might be formulated thus : 

 What are the chemical processes which, being logically assumed in 

 connection with known facts of geology, could have produced from 

 the compounds of carbon and hydrogen in the rocks the vast quan- 

 tities of bitumen, petroleum and natural gas ? 



