MEMOIR OF S. F. EMMONS 21 



delayed, and since his sudden death has been still further postponed, 

 but the manuscript was left in such shape that it can be edited by 

 hi« colleague as a fitting close of an earnest career. It is worthy of 

 note here that, notwithstanding all recent developments, Mr. Emmons' 

 conclusions were not essentially changed, but, on the other hand, addi- 

 tional evidence tended rather to confirm his original views, with some 

 modification and revision. 



During the following years of Emmons' active duties most of his im- 

 portant contributions to geological science were issued as official docu- 

 ments of the Geological Survey. As they are accessible to all, and the 

 titles are found in the list of his scientific writings appended to the bio- 

 graphical sketch, it seems unnecessary^ to mention them all, considering 

 the limited space available. They appear in one or another of the many 

 forms of publications adopted by the Government Bureau. Several of 

 the more important of them were published as descriptive texts accom- 

 panying folios of the Geologic Atlas. Many of these writings are of the 

 highest value and bring out his power of presenting geological details in 

 a lucid, simple style. In some of these he was the sole autho'*, while in 

 others he shared with his assistants the preparation of the text*' Among 

 these folios may be mentioned the "Geology and Mineral Eesources of 

 Elk Mountain," "The Butte Special," "The Tintic Special," represent- 

 ing widely separated mining areas in Colorado, Montana, and Utah. To 

 the annual reports he contributed a number of articles, among them an 

 exhaustive one entitled "Mines of Custer County. Colorado," which ap- 

 peared in the seventeenth report, issued in 189 G. In the same year 

 there was issued from the press the well known and elaborate mono- 

 graph on the "Geology of the Denver Basin," a volume devoted to sti-uc- 

 tural problems of the broad region of country lying east of the Front 

 Eange, a work in striking contrast to Mr. Emmons' more recent contri- 

 butions in the line of economic geology. In this volume he is aided by 

 his two principal assistants in Colorado, Mr. Whitman Cross and Mr. 

 George H. Eldridge, who furnished a large part of the text. In the 

 series of Professional Papers published by the Survey may be found 

 articles from Mr. Emmons' pen, serving as introductions to the work of 

 younger men, upon mining districts in the far West. 



Notwithstanding the fact that administrative duties occupied so large 

 a share of his time, Mr. Emmons was able to contribute to scientific 

 journals and societies on a wide range of geological subjects, including 

 dynamic problems, orographic movements, and the many phases of the 

 genesis of ore bodies. In this connection it is only necessary to mention 

 his paper on Secondary Enrichment of Ore Deposits. Mr. Emmons' 



