32 BULLETIl^ 102, VOL. 1, UNITED STATES NATIONAL MUSEUM. 



logical unit or pool. In consequence the joint ownership or joint 

 exploitation of a single pool results in the inability to apportion the 

 product on any arbitrary basis of vertical boundary planes,^ and the 

 oil, therefore, is practically no man's property until it is got above 

 ground. This circumstance is almost invariable and the customary 

 method of exploiting the single oil pool by a series of small, inde- 

 pendent holdings has cost an inordinate toll of waste and loss.^ The 

 economics of oil production is out of adjustment with the geological 

 occurrence of oil and the latter, being a physical fact, can not be 

 altered. 



ORIGIN. 



Few questions in geologic theory have met with more discussion 

 than the origin of petroleum. It is reasonably certain, however, that 

 petroleum in the main is of organic origin and represents the natural 

 distillation products of plants and animals buried in the muds and 

 oozes of ancient swamps and seas. Vast rock formations, indeed, are 

 known which are nothing more than the accumulated debris of in- 

 numerable organisms, compressed, hardened, and changed into rock. 

 Fossiliferous limestones, phosphate rock, and coal seams are familiar 

 examples which underlie thousands of square miles of the earth's 

 surface. It would be strange, in fact, if in the process of formation 

 oils were not produced, when organic products to-day, subjected to 

 heat and pressure, yield oily substances not unlike petroleum. Sedi- 

 ments carrying organic remains are sufficiently abundant and wide- 

 spread to account for all the petroleum that the oil fields of the world 

 give promise of producing. 



DISTRIBUTION. 



Wliile petroleum is of very common occurrence in traces, areas 

 underlain by commercial quantities are somewhat restricted and 

 fields of gi'eat importance are few. Thus in spite of an intensive 

 search for new oil regions and vigorous campaigns of development 

 carried on in all parts of the world, the entire supply comes largely 

 from three countries, as shown in the accompanying chart (fig. 2). 



In the United States, the output is derived from a number of 

 widely scattered regions known as " fields," whose distribution is 

 shown on the map (fig. 3), and whose importance is indicated by the 

 charts (figs. 8 and 9.) In a broad way, these fields fall into two 

 groups — those of the eastern half of the United States, bound into a 

 single unit by an extensive system of pipe lines, and those of Califor- 

 nia, connected with the rest of the country by railroad transporta- 



^ It is a rather curious commentary on the obsoleteness of American mining law that 

 vertical boundaries are applied to oil deposits where they have no meaning, but are not 

 applied in the case of outcropping ore deposits, where they are both appropriate and 

 desirable. 



2 See figure 12. 



