BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



VOL. 27, PP. 491-514, PL. 19 SEPTEMBER 1, 1916 



PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY 



COEEELATION AND CHEONOLOGY IN GEOLOGY ON THE 

 BASIS OF PALEOGEOGEAPHY 1 



BY CHAELES SCHTJCHEET 



{Read before the Paleontological Society August 3, 1915) 



CONTENTS 



Page 

 Rise of chronology 491 



Conclusions of the earlier geologists 491 



Permanency of continents and oceans 493 



Disturbances and revolutions 495 



Breaks 497 



Methods underlying a determined chronology 497 



General discussion of methods 497 



The sedimentary method 498 



The paleontologic method 499 



The paleogeographic method 500 



The diastrophic method 502 



Paleogeography of western North America during the Mesozoic 505 



Introductory 505 



Triassic time 505 



Jurassic time 507 



Shastan time 509 



Cretaceous or Chico time 513 



Eise of Chronology 



conclusions of the earlier geologists 



Geologic chronology had its beginning in north Germany in the super- 

 posed formations of Lehmann (1756) and Fiichsel (1762), which are now 

 included under the terms Permian and Triassic. Werner (1775-1817), 

 whose knowledge of the geographic distribution of formations was ex- 



1 This is the third of four papers read at the summer meeting of the Paleontological 

 Society at the University of California, August 3, 1915, in the symposium entitled "Gen- 

 eral consideration of paleontologic criteria used in determining time relations." 

 Manuscript received by the Secretary of the Geological Society April 6, 1916. 



XXXVI— Bull. Geol. Soc. Am., Vol. 27, 1915 (491) 



