BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol 34. pp. 285-308 JUNE SO, 1923 



BUILDIXG OF THE SOUTHEEjS^ EOCKY MOUXTAIXS ^ 



BY WILLIS T. LEE 

 WITH 



NOTES OX ISOSTASY 



BY C. E. VAX OESTRAXD 



AND 



ELASTIC YIELDING OF THE EARTH' S CRUST UNDER A LOAD OF 



SEDIMENTARY DEPOSITS 



BY WALTEB D. LA:\IBERT 



CONTENTS 



Page 



Introduction 285 



Recital of certain outstanding facts 2S6 



The Southern Rockies as a quantitative test 291 



Explanation of the movement 292 



Conclusion 299 



Notes on isostasy ; by C. E. Van Orstrand 300 



Elastic yielding of the earth's crust under a load of sedimentary deposits ; 

 by Walter D. Lambert 305 



Introduction 



This paper concerns the Southern Eocky Mountains, lying chiefly 

 in Colorado. Certain recorded observations relative to them are recalled 

 and possible causes of their rise discussed. It is shown that the theory 

 of lateral compression, frequently advanced as the cause of mountain- 

 building and recently applied by E. T. Chamberlin to the Colorado 

 Eockies,^ is not in harmony with many of the observed facts, and the 



^ Published with permission of the Director of the U. S. Geol. Survey. 

 Received by the Secretary of the Society January 7, 1923. 



This paper is one of a series composing a "Symposium on the stnicture and history 

 of mountains and the causes of their development." 



2 R. T. Chamberlin: The building of the Colorado Rockies. Jour. Geol., vol. xxvii^ 

 1919, pp. 145-164, 225-251. 



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