GEOLOGY — LOUDER BACK. 191 



STUDY OF THE BASIN RANGE STRUCTURE AND GLAUCOPHANE AND 

 ASSOCIATED SCHISTS OF CALIFORNIA AND OREGON. 



Louderback, George D. t Nevada State University, Reno, Nevada. 

 Grant No. 167. (Continuation of Grant No. 66.) $1,300. 



The first part of this study had been completed and the work during 

 the past year was devoted to the schists. The questions involved 

 included (a) their distribution areally and geographically ; (b) their 

 exact geological relations ; (c) their petrographical characters and 

 description ; (d) the materials from which they were formed ; (/:) the 

 active agent or agents giving rise to their formation ; (/) the process 

 by which the metamorphism was brought about. 



Among the chief difficulties encountered are the sporadic occur- 

 rence and the lack of contacts — in fact, the general lack of positive 

 evidence. This has led to the most diverse views by different observers, 

 and after studying one or two localities carefully it was seen that 

 the utmost care in some areas might yield meager results, and that the 

 chance occurrence of a good contact or of a definite transition form 

 might play an important part in solving the question of origin. 



Furthermore, it was found that a number of subsidiary questions 

 should very desirably be answered before the main question was 

 solved. Among these were, the age of the sedimentary rocks with 

 which the schists are associated, and whether they are associated with 

 rocks of different ages and lithological characters in California and 

 Oregon, as appears from the literature. The study indicated that 

 the Mesozoic of Oregon was not correctly classified and presented in 

 the atlas sheets now published, and that the subdivision of the rocks 

 of this era and the associations of the schists are the same as in central 

 California. 



As for the main question, the schists at several localities in southern 

 Oregon and in central California have been studied and a large 

 number of specimens gathered. 



Dr. Louderback expects to continue his work and when finished 

 to present his results for publication. 



