ACADBM* OF SCIENCES] BIOGRAPHY 5 



Doctor Becker's next field of investigation comprised, under the administration of J. W. 

 Powell, 2 a study of the quicksilver deposits of the Pacific coast. This proved a somewhat pro- 

 longed investigation and for its satisfactory completion necessitated a study of the deposits of 

 similar nature in Italy and Spain. Though under governmental authority, he was obliged to 

 carry on this portion of the work at his own expense. The results of these studies appeared in 

 1888, as Monograph XIII of the survey series, under the caption of " Geology of the Quicksilver 

 Deposits of the Pacific Slope." 



In this report it was shown that all of the ores were deposited in preexisting openings and not 

 by substitution. Where these openings were fissures the deposits were veins. Contrary to the 

 generally received belief, veins of quicksilver ores, it was shown, are very common and were 

 filled from solutions, not by sublimation, the material being deposited as black amorphous 

 sulphide and subsequently converted into cinnabar. In connection with the deposits a new 

 class of veins was proposed, called "chambered veins." It was shown that not only cinnabar 

 but gold and the sulphides of iron, copper, and antimony and zinc dissolve in solutions of 

 sodium carbonate charged with hydrogen sulphide, such as occur in great abundance as spring 

 waters in volcanic regions. The report contained a digest of the descriptions of all the impor- 

 tant or interesting quicksilver ore deposits of the world. 



In the same volume it was shown for the first time that the Cretaceous and Tertiary forma- 

 tions in this part of California were continuous in life and sedimentation. Attention was 

 also called to a great and hitherto unnoticed upheaval in the Coast Ranges, at the beg innin g 

 of the Cretaceous period. Becker thought to show further that in some cases serpentine 

 resulted from the action of mineralized solutions on sandstones. 



At the close of the census investigation, Mr. J. S. Curtis, who had been one of Becker's 

 assistants in that inquiry, joined the survey and was directed by him to study the Eureka 

 mines. Mr. Curtis's volume, Silver Lead Deposits of Eureka, Nevada, Monograph VII, 1884, 

 of the survey series, was well received by those interested in mining. 



The above completes the list of Doctor Becker's monographic studies, but by no means 

 closes or limits the period of his activity. In fact, they were but the beginning. While finish- 

 ing the writing and attending to the publication of the report on quicksilver, he elaborated a 

 plan to be carried out by his assistants, Messrs. H. W. Turner and W. Lindgren. It was in- 

 tended that this investigation should cover the west slope of the Sierras for the entire length 

 marked by frequent or important gold mines. The plan included four memoirs on the lithology, 

 descriptive geology, mining geology, and systematic geology of the region. He proposed that 

 the mapping and the descriptive memoir should be done by assistants under his supervision, 

 while his own attention was to be given to the investigation of the questions arising in the work, 

 such as the nature and origin of the structure, the character and effect of the glaciation, the 

 origin and history of the ore deposits, the relation of the eruptive rocks to one another, and 

 the like. 



This investigation was never completed as planned. About 7,600 square miles were mapped 

 and much preliminary work was accomplished in areas of which the topographic basis has been 

 only lately completed. 



Commenting upon this, Doctor Becker wrote: 



It might seem more expedient to have begun this work with the ore deposits, but a little consideration 

 shows that this would have involved loss of time and labour. If one were to begin with the gold bearing gravels,, 

 questions which would arise immediately are: What is the source of the pebbles? What are the relation of the 

 channels to one another and to the present drainage system? What is the age of the deposits? These ques- 

 tions can be solved only by a study of the general geology of the country. If one were to begin with the quartz 

 veins more numerous problems of a similar character would compel a return to a preliminary study of the-, 

 geological history of the region. 



Becker's personal studies of the gold belt led to seemingly definite solutions of a number 

 of questions. Some of his conclusions were as follows: There is strong evidence of a post- 



1 King resigned on Mar. 11, 1881, and Powell was appointed to his position three days later. Doctor Becker's position on the survey does not 

 to have been affected by the change. 



