VOLUME XXIII NUMBER 2 



THE 



JOURNAL OF GEOLOGY 



FEBRUARY-MARCH 1915 



POST-CRETACEOUS HISTORY OF THE MOUNTAINS OF 

 CENTRAL WESTERN WYOMING^ 



ELIOT BLACKWELDER 



University of Wisconsin 



TABLE OF CONTENTS 



Introduction 



Subject and Scope 

 Data and Acknowledgments 

 Bibliography 

 Post-Cretaceous Geologic History 

 • Antecedent Conditions 

 Post-Cretaceous Orogenic Disturbance 

 Early Eocene Erosion 



Deposition of the Eocene and Oligocene Formations 

 Mid-Tertiary Deformation 

 Later Tertiary Planation 

 Early Quaternary Rejuvenation 

 General Effects of Erosion in the Quaternary Period 

 Quaternary Cycles of Stream Erosion 



Fremont Cycle 



Union Pass Cycle 



Black Rock Cycle 



Circle Cycle 



Lenore Cycle 

 Quaternary Glaciation 



Pinedale Stage 



Bull Lake Stage 



Buffalo Stage 



Summary of Glaciation 

 Work of Gravity with the Aid of Weathering 

 Wind Work in the Quaternary Period 

 SuiDkiARY OF Conclusions 



' Published by permission of the Director of the U.S. Geological Survey. 



Vol. XXIII, No. 2 97 



