MAY 29 1911 



No. 4. — An Excursion to the Grand Canyon of the Colorado. 

 By W. M. Davis. 



TABLE OF CONTENTS. 



Introduction 



Itinerary 



Summary of Previous Work 



Newberry 



Powell 



Dutton 



The Rook Series 



Local Names, Maps, etc. . . . 



The Great Denudation 



Two Cycles of Denudation 

 The Mature Valleys of the Kai- 

 bab and Coconino Plateaus . 

 The Landslides of Vermilion and 



Echo Cliffs 



The Migration of Certain Divides 



Divide near Pipe Spring . . 



Relation of the Pipe Spring 



Divide to the Pipe Spring 



Fault 



The Cedar Ridge Divide under 



Echo Cliffs 



Migrating Divides in Arid Re- 

 gions 



The Permian Scarps under the 



Shinarump Cliffs .... 



The Development of Talus . 



Perched Boulders 



Spurs and Ravines .... 



The Stripped Plateaus . .... 



Dates of Displacements .... 



The Eastern Flexures .... 



The Earliest Flexures . . . 



The Kaibab and the Echo 



(Paria) Flexures . . . . 



The Crags of Echo Cliffs . . 



The Western Faults 



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The West Kaibab Faults . 

 The Toroweap Fault . . . 

 The Sevier Fault Southwest of 



Pipe Spring 143 



Topographic Effects of Fault- 

 ing obliterated or reversed 



by Erosion 145 



The Hurricane Fault .... 146 

 The Grand Wash Fault ... 147 

 The Western Monoclinal Flexures 148 

 The Displacements of the High 



Plateaus 150 



Origin of the Drainage System . 151 

 General Explanation by Antece- 

 dence 151 



Replacement of Antecedence by 



Other Explanations . . . 152 

 The Smaller Streams of the 



Grand Canyon District . . 153 

 The Streams of the San Rafael 



Swell 154 



The Summit Valleys of the 



Kaibab 155 



The Origin of the Colorado in 



the Grand Canyon District . 158 

 The Geological History of the 



Region 159 



The Effect of the Flexures . 160 

 The Effect of the Faults . . . 161 

 The Bends of theGrand Canyon 164 

 Speculative Character of the 

 Preceding Sections . . . 160 

 The Erosion of the Grand Canyon 167 



The Canyon Cycle 167 



Comparison of Glen and Marble 

 Canyons 167 



