86 REPORT OF THE SECRETARY. 



district, aud the mines in the vicinity of Steamboat Springs, to Ire fol- 

 lowed later by an examination of the cinnabar deposits of Guadaloupe 

 and New Almaden. The climate of California makes field-work possi- 

 ble at all times of the year, and Mr. Becker kept in mind the desirability 

 of not only making a careful study of the surface geology of the are.i 

 immediately under investigation, but also of utilizing all trips to and 

 from the field of work for the purj)Ose of obtaining a thorough knowl- 

 edge of the general geology of California, and its relation to the quick- 

 silver deposits. In addition to this, special trips were made whenever 

 necessary to localities thought to be instructive or furnishing any clue 

 to the solution of the geologic problems of this region. With such ends 

 in view, the construction of a geologic section through the Coast liange 

 was undertaken. In view of the extensive studies made by Mr. Becker 

 and his assistants, and as a check upon their conclusions concerning the 

 age of the quicksilver-bearing rocks of the Pacific coast, it seemed wise, 

 before proceeding further, to have some competent [)ale()ntologist review 

 the results obtained by the State survey and such other material as 

 had been procured recently by Mr. Becker. Dr. C. A. White was as- 

 signed this duty, and proceeding to California he first made a study 

 of the Chico, Tejou, and Miocene groups, and then, in company with 

 Mr. Becker, visited the several mining districts under consideration, 

 the Cretaceous and Paleozoic formations of Butte County, and certain 

 other localities on the McCloud River, and in Shasta and Mariposa 

 Counties. They then proceeded as far north as Eugene City, Oreg., 

 for the purpose of examining a large and very instructive collection of 

 fossils in that city. 



Much microscopic and chemic* work has been accomplished in the 

 laboratory of this division, in connection with the cinnabar investiga- 

 tions. 



Assistant Geologist Curtis completed his report on the Eureka min- 

 ing district, and early in the year proceeded to Washington to superin- 

 tend its publication. When not engaged in this task, his time was de- 

 voted to experimenting for the purpose of devising improved methods 

 for determining minute quantities of precious metals in ores. 



Volcanic Bocks. — Having nearly completed the manuscript of his 

 memoir on the Hawaiian volcanoes, Capt. C. E. Dutton, U. S. A., in 

 pursuance of his investigations relative to volcanic phenomena, pro- 

 ceeded to Fort Wingate, IST. Mex., in July, for the purpose of making 

 a thorough examination of Mount Taylor and its vicinity, a region which 

 in past time was one of great volcanic activity. In the mean time the 

 investigations previously conducted in the Cascade Eauge were not for- 

 gotten, and Assistant Geologist Diller spent the field season in the 

 neighborhood of Mount Shasta with most gratifying results. An area 

 embracing 400 square miles was explored; the successive lav'aflows 

 which had taken place from the main crater, as well as from the many 

 vents upon the slopes of this extinct volcano, were traced; the limits of 



