580 abstracts: geology 



Every effort has been made to make the volume interesting as well 

 as accurate. Matter slightly more detailed or technical than that in 

 the body of the text has been separated as footnotes, and a glossary 

 has been provided for such geologic terms as it was necessary to use. 

 The more important sources of geologic information on the region are 

 listed in the back of the book, and a table showing the principal divi- 

 sions of geologic time appears on the back of the title-page. Each 

 map unfolds so that it can be consulted conveniently without turning 

 the page which the traveler may be reading. The halftone views and 

 text figures have been chosen with care to convey definite information. 



F. L. R. 



GEOLOGY. — Guidebook of dhe Western United States, Part B, the 

 overland route, with a side trip to Yellowstone Park. W. T. Lee, 

 R. W. Stone, H. S. Gale, and others. U. S. Geol. Survey Bull. 

 612. Pp. 244, with maps and illustrations. 1915. (For sale by 

 Superintendent of Documents, Washington, D. C; price $1.) 

 A handbook for the traveler which deals not only with the geology 

 but with the natural resources, history, and development of the country 

 between Omaha and San Francisco. It shows how differences in scen- 

 ery and climate depend upon past geologic events and dispels the mo- 

 notony of the great plains by taking the traveler back to times when 

 these regions supported vegetation very (iifferent from their present 

 scanty covering and were inhabited by animals of strange forms and 

 huge size. The scenery of the mountains acquires additional interest 

 from the explanation of the earth movements and the resulting rock 

 structures to which fundamentally the mountains forms are due. 

 Even the desert becomes attractive when the traveler is told of its 

 vanished lakes and is shown the old beach lines which their waves cut 

 on the now arid hillsides. 



The book is intended to educate by being interesting, to win hearing 

 for the story of geology by telling it in a clear and simple way, with 

 abundant illustration from the car windows not only of the story itself 

 but of its intimate connection with- human life. F. L. R. 



GEOLOGY.— (reo^ogr^ a7id mineral deposits of the National mining dis- 

 trict, Nevada. Waldemar Lindgren. U. S. Geol. Sui'vey Bull. 

 601. Pp. 58. 1915. 

 The National mining district is in Humboldt County, Nevada, 



near the Oregon line. No large production of precious metals had 



