118 University of California Publications in Geology [Vol. 7 



INTRODUCTION 



Some observations were made on structural and physiographic 

 features in a section of the southern Great Basin during a recent 

 reconnaissance conducted for the Department of Palaeontology 

 of the University of California, under the general direction of 

 Professor John C. Merriam. Since the main purpose of the 

 undertaking was the collection of vertebrate fossils, relatively 

 little time was available for geologic observations. The follow- 

 ing notes, therefore, are much scattered and can make no pre- 

 tence to the completeness and accuracy necessary for a strictly 

 scientific treatment of the geology. However, certain features 

 were noted which have not been described by previous investi- 

 gators of the region. 



The area examined embraces that portion of the southern 

 slope of the Sierra Nevada situated between Jawbone Canon, 

 northeast of Cinco Station on the California and Nevada Rail- 

 road, and Indian Wells, southeast of Walker Pass and some 

 miles south of the Inyo-Kern County line. Most of the field 

 work was done in the El Paso Range, a few miles south and in 

 en echelon relation with the above-designated section of the 

 Sierra Nevada. Only that portion of the El Paso Range west 

 of the summit of Black Mountain was studied. 



The writer is under great obligation to his field associates, 

 Messrs. S. H. Gester, George E. Stone, and John Guintyllo, and 

 for microscopical examinations of rocks to Professor George 

 D. Louderback, Mr. R. G. Davis, and Mr. John R. Suman. 

 Acknowledgements are also due to Professor Andrew C. Lawson 

 for information concerning erosion cycles and periods of de- 

 formation in the southern Sierra Nevada. 



