92 PROCEEDINGS OF THE SAIXT LOUIS MEETING 



dously long Precambrian history of the world, which probably much exceeds 

 in length the latter parts of the world's history. He seems a little too pessi- 

 mistic, however, in regard to the working out of a general classification of the 

 Precambrian. The close parallelism of the succession found in different re- 

 gions seems to suggest a real basis for classification. 



Dr. W. J. Miller : Doctor Wilson has sounded a note of comfort to some of 

 us at least who work with Precambrian rocks. For one, I have not been able 

 to keep pace with the ideas definitely expressed in several recent correlation 

 tables. In the Adirondack region I have even hesitated to use the old term 

 "Laurentian" because there is so much difference regarding its use. I agree 

 with Doctor Wilson when he maintains that definite correlations covering the 

 region from western Ontario to the Saint Lawrence Valley are out of order 

 until many more field facts are well in hand. 



FURTHER STUDIES IN THE NEW YORK SILURIC 

 BY GEORGE H. CHAD WICK 



i Abstract) 



The analysis and correlation of the Cayugan "wateiiimes" has been carried 

 eastward to Cayuga Lake in the effort to show the true position of the so- 

 called Cobleskill and Rondout, in the western sections. Studies also made of 

 the New York Clinton sections have suggested the necessity for some readjust- 

 ments in the present classification. 



Eead by title in the absence of the author. 



RELATION OF THE OIL-BEARING TO THE OIL-PRODUCING FORMATIONS IN 

 THE PALEOZOIC OF NORTH AMERICA 



BY AMADEUS W. GRABAU 

 iAl)St7'aCt) 



The oil-bearing formations which will be considered are : The Trenton lime- 

 stone, the Onondaga (Corniferous) limestone, the Upper Devonic sands of 

 southwestern New York and northwestern Pennsylvania, and the Berea sand- 

 stone. The widely held view that the oil of the Trenton and Onondaga lime- 

 stones was produced from the soft part of the animals which secreted the 

 calcareous structures from, which these limestones are formed is untenable, 

 since the conditions of accumulation of zoogenic and phytogenic limestones in 

 the sea involves the destruction of the organic matter by contemporaneous 

 scavengers. Even where the limestones are wholly composed of shells and 

 corals, these are practically pure lime accumulations, free from organic ma- 

 terial. That the oil of the Upper Devonic and of the Berea sandstone could 

 be derived from the organisms contained from the inclosing beds need hardly 

 be seriously considered. 



In the case of the oil-bearing formations mentioned, and probably in the 

 majority of oil-bearing formations of all horizons, the source of the oil is to 

 be sought in the black shales, either sapropelitic or humulitic. which occupy 

 corresponding horizons in an adjoining area and from which the oil (and gas) 



