404 NEW YORK STATE MUSEUM 



contributes so much to the completeness of the geologic column 

 of New York. 



In these previous movements of the crust, more or less relief 

 was given to the land surface or sea floors of the times in which 

 they occurred, and many low arches and synclines resulted in 

 this way; but no prevailing direction is thus far found in any of 

 these ancient structures, aside from this southerly dip already 

 named. 



It is not counted necessary in a paper designed specially for 

 the general reader, to furnish proof of the statements already 

 made as to the order of arrangement of the several substances 

 contained in porous rocks. It is enough to say that the facts 

 from every oil field fall into line in support of these statements. 

 Moreover they harmonize so well with the teachings of physics 

 that they soon come to be counted necessary truths and no 

 grounds are apparent from which attacks can be directed aga'nst 

 them. Even the disposition to make such attacks seems to have 

 passed away. 



The Trenton limestone field or northwestern Ohio, one of the 

 latest oil and gas fields to be exploited, furnishes the most satis- 

 factory and conclusive proofs on all these points. Five or six 

 feet of relief have proved ample to keep gas wells dry for days 

 and weeks, and wells drilled solely for gas and operated as such, 

 have been slowly turned into highly productive oil wells, and, 

 in multitudes of cases, have, at a later date, been overrun with 

 salt water. 



Section 2 



Origin of petroleum, natural gas, maltha and asphalt 



The readers of this paper will expect some attempt to answer 

 the questions that human curiosity everywhere raises as to the 

 origin of the bituminous series. The series has long been known 

 to man. We find mention of it in the oldest records and tradi- 

 tions of the race, but its real value and importance have been 

 mainly developed in the present century and very largely in our 

 own day. 



The bituminous series contains at least four well-marked ele- 

 ments; namety, natural gas, petroleum, maltha or mineral tar, 



