BULLETIN OF THE (GEOLOGICAL SOCIETV OF AMERICA 

 Vol. 15, pp. 243-266 June 23, 1904 



GEOLOGY UNDER THE PLANETESIMAL HYPOTHESIS OF 



EARTH-ORIGIN 



BY HERMAN LE ROY FAIRCHILD 



(Read before the Society January i, 1904.) 

 CONTENTS 



Page 



Introduction 243 



Comparison of the nebular and planetesimal hypotheses 244 



Origin of the atmosphere 245 



Origin of the ocean 247 



Earliest sedimentary rocks 248 



Volcanic phenomena . 249 



Source of the hydrocarbons 252 



Genesis of metalliferous deposits 254 



Origin of gypsum and salt deposits 254 



Geologic climates 255 



Glaciation 258 



Diastrophic movements . . . 258 



Irregularities of the earth's figure . 260 



Life on the earth 260 



Conclusion 261 



Discussion 262 



Edward H. Kraus' comments .... 262 



Willis T. Lee's comments 263 



Israel C. Russell's comments 264 



Oxygen in the air . 264 



Volcanoes 264 



Color of rocks and climate 265 



Corrugated mountains 265 



Frederick W. Sardeson's comments 266 



Introduction 



The nebular hypothesis was not a scientific induction, but cosmic 

 philosophy. Propounded by Swedenborg and Kant, it was given mathe- 



By special action of the Society, a preliminary edition of 300 copies of this paper was printed 

 without covers on January 30, 1904, under the title, "Geology under the new hypothesis of earth- 

 origin," and distributed to members of the Society for discussion. The pagination, from 1 to 20, 

 was on the center of the bottom of the page. The discussion resulting therefrom has been ap- 

 pended to this paper. Communications or portions of communications which discussed the 

 planetesimal hypothesis are not included here, as the paper is not a treatise on that hypothesis, 

 but only on its geologic bearings. — Editor. 



XXXII— Bull. Geol. Soc. Am., Vol. 15, 1903 (243) 



