i6o REVIEWS 



Commercial deposits are known of many of the minor non-metallic 

 minerals but as yet there has been little production. Great interest 

 has been taken in Western Australia in the world-wide search for petro- 

 leum but so far there has been no noteworthy development. Two 

 asbestos deposits are described. Chrysotile asbestos of good quality 

 is found at a number of localities over a distance of 200 miles. The 

 fiber compares favorably with that found in any other part of the world 

 with the possible exception of the best Canadian, and although the veins 

 are small the high quality makes it probable that important development 

 will take place. 



Under the heading "Some Problems Awaiting Solution," the future 

 work of the Survey is discussed. Among others, the following statement 

 is significant: 



A more thorough investigation than has yet been found possible into those 

 multifarious petrological problems which have such an intimate bearing upon 

 the genesis of the ore deposits of the State, and the conditions which govern 

 their deposition and to a certain degree control the distribution, extent and 

 value of the mineral deposits. 



The ofi&cers of the Geological Survey of West Australia have done 

 much valuable work in the past and their future contributions to the 

 science will be looked for with keen interest by their brother geologists 

 in other parts of the world. 



A. H. B. 



Guide Book of the Western United States, Part E. The Denver and 



Rio Grande Western Route. By Marius R. Campbell. 



Bulletin 707, U.S. Geological Survey, Washington, D.C. 



Pp. 266, pis. 96, figs. 63, maps 10. 



There has recently appeared the fifth part of the well-known Guide 



Book of the Western United States which the U.S. Geological Survey 



inaugurated at the time of the San Francisco Exposition in 191 5. This 



latest guide, which follows the plan adopted in the earlier bulletins of 



the series, describes the scenery and treats of the geology of one of the 



most scenic of the western railway routes. In addition to treating of 



the tracts immediately adjoining the Denver and Rio Grande Western 



Railroad between Denver and Salt Lake City, it includes a number of 



one-day trips that may be made to points of interest from Denver, 



Colorado Springs, Canon City, and Salt Lake City. 



