62 REVIEWS 



Molybdenite is present at two localities. The gold occurs in the native 

 state. The mineralization was subsequent to the intrusion of the 

 Mesozoic granite batholiths and the related stocks and dikes. The 

 depositing solutions were probably residual emanations from these 

 magmas. The gold lodes of the Kenai Peninsula correspond, therefore, 

 both in age and general association, with the similar deposits elsewhere 

 in Alaska. 



H. R. B. 



Field Geology. By Frederic H. Lahee. New York: McGraw- 

 Hill Book Co. 12 mo, pp. xxiv+508. $3.00. 



This work is divisible into two parts: an empirical treatment of 

 geologic phenomena (twelve chapters), and a compilation of field and 

 office methods (six chapters). 



The first part covers well-nigh the whole field of phenomenal geology 

 and will find its greatest usefulness among undergraduate students. 

 For working geologists the most valuable matter will be found in the 

 chapters on "Geologic Surveying," "Modes of Geologic Illustration," 

 "Geologic Computations," and "Preparation of Geologic Reports," and 

 in appended tables. One wishes that more of the field and ofiice methods 

 contributed in the last few years to economic geology were presented. 



In carrying out the scheme of empirical treatment of phenomena 

 the author has constructed many carefully analyzed "keys" or tables, 

 Hke those of mineralogical and botanical texts. The reviewer has tried 

 out the work in two field courses, placing it in the hands of the students 

 simply as a reference, and has found it very valuable, though the students 

 did not voluntarily make use of the "keys." These may find their use- 

 fulness among beginners without field association with more experienced 

 men. 



The author has digested pertinent matter from such works as 

 Leith, Structural Geology; Leith and Mead, Metamorphic Geology; 

 Grabau, Stratigraphy; Lindgren, Mineral Deposits, etc., and presents 

 valuable material from the field handbooks of Hayes, of Farrell, and of 

 Geikie. Important contributions to periodical literature have also been 

 drawn upon. 



The book is one of the McGraw-Hill series of limp-cover handbooks, 

 with narrow margins and rounded page corners. Its 500 pages of thin 

 paper will prove no burden in the pocket. 



J. H. B. 



