CONTENTS (Coutinued) 



Page 



The Simple Type of Folded Ranges 184 



Relation to Surface 184 



The Dominguez Range 185 



Section of the Strata 187 



Flexured Folds of the Ventura Ranges 189 



PART V 

 THEORIES OF THE CAUSES OF FAULTING 



The Contractional Theory 191 



The Theory of Isostasy 192 



Kinds of Crustal Movements 195 



The Up-and-Down Movements 195 



The Horizontal Movements 197 



Renewal of Movement Along Old Fault Lines 197 



Causes of the Direction of Trends 198 



Causes of the Folding 201 



Causes of the Changes of Trends 202 



Recurrences of Trends 202 



PART VI 

 GEOLOGIC HISTORY OF SOUTHERN CALIFORNIA 



Outstanding Epochs 205 



Periodicity of Earth Movements 206 



Southern California Before Glacial Period 208 



The Pliocene Peneplain 208 



Southei-n California During the Glacial Epochs 209 



Causes of Earth Movements in the Glacial Epochs 209 



Interesting Events in this Vicinity During the Glacial Epochs 212 



Relations of the Physiography to Faulting and Seismicity. . 214 



Geologic History of the Fault Systems 215 



Testimony of the Strata 218 



Ages of the North-South Groups of Structures 219 



Relative Age of the Northeast Trends 219 



Age of the Transverse Faults 220 



Relative Ages of the Northwest Groups 220 



Evidence of Pleistocene Age in Some of the Master Fauls. . 221 



Fault Movements of Recent Times 224 



This Explains Southern California 225 



PART VII 



SUMMARY 



Summary of Conclusions 227 



XIII 



