UNIVERSITY OF CALIFORNIA PUBLICATIONS 

 Bulletin of the Department of Geology 



Vol. 3, No. 22, pp. 423=475. ANDREW C. LAWSON. Editor 



THE RIVER TERRACES 



OF THE 



ORLEANS BASIN, CALIFORNIA 



BY 



Oscar H. Hershey. 

 CONTENTS. 



PAGE 



Introduction 423 



The Rocks of the Region 424 



Brief Outline of Geomorphogeny 424 



Detailed Description of Terrace Remnants 428 



The 850-foot Terrace 428 



The 675-foot Terrace 431 



The 475-foot Terrace 432 



The 120-foot Terrace 433 



The 70-foot Terrace 441 



The 45-foot Terrace 443 



The Modern Canon 447 



Characteristics and Differences of Terraces 447 



Relation to Neighboring Glacial Deposits 449 



General Discussion 459 



Changes of Grade 459 



Changes of Climate 462 



Relative Age of Different Terraces 467 



Correlation 471 



INTRODUCTION. 



The village of Orleans is situated on the north bank of the 

 Klamath River, in the northeastern part of Humboldt County, 

 California. Its vicinity is characterized by the finest display 

 of river terraces that I have ever seen. A somewhat desultory 

 study of them has yielded evidences of changes of grade and 

 of climate that are worthy of record. I will first briefly outline 

 the bed-rock geology and the geomorphogeny of the region, after 

 which I will give a detailed description of the various ter- 

 race remnants, followed by a summary of their characteristic 

 features and differences, then discuss the problems presented 

 by them and finally correlate them with the Quaternary terrace 

 system as developed in other portions of the State. 



