LIST OF PLATES 



PLATE 



1. Mount Balfour and the Balfour Glacier in the Selkirks . Frontispiece 



FACING PAGE 



2. A. Layers compressed in experiments and showing the effect of a com- 



petent layer in the process of folding 44 



B. Experimental production of a series of parallel thrusts within 



closely folded strata 44 



C. Apparatus to illustrate shearing action within the overturned limb 



of a fold 44 



3. A. An earthquake fault opened in Formosa in 1906 with vertical and 



lateral displacements combined .72 



B. Earthquake faults opened in Alaska in 1889 on which vertical 



slices of the earth's shell have undergone individual adjustments 72 



4. A. Experimental tank to illustrate the earth movements which are 



manifested in earthquakes. The sections of the earth's shell are 

 here represented before adjustment has taken place ... 82 



B. The same apparatus after a sudden adjustment .... 82 



C. Model to illustrate a block displacement in rocks which are inter- 



sected by master joints ......... 82 



6. A. Once wooded region in China now reduced to desert through de- 

 forestation .'..'. 156 



B. " Bad Lands " in the Colorado Desert . . . . . .156 



6. A. Barren Karst landscape near the famous Adelsberg grottoes . . 188 

 B. Surface of a limestone ledge where joints have been widened through 



solution 188 



7. A. Ranges of dunes upon the margin of the Colorado Desert . . 210 

 B. Sand dunes encroaching upon the oasis of Oued Souf, Algeria . 210 



8. A. The granite needles of Harney Peak in the Black Hills of South 



Dakota 216 



B. Castellated erosion chimneys in El Cobra Canon, New Mexico . 216 



9. Map of the High Plains at the eastern front of the Rocky Mountains . 220 



10. A. View in Spitzbergen to illustrate the disintegration of rock under 



the control of joints . 228 



B. Composite pattern of the joint structures within recent alluvial 



deposits of the Syrian Desert . . . . . . . 228 



11. A. Ripple markings within an ancient sandstone .... 232 

 B. Wave breaking as it approaches the shore 232 



xix 



