12 PROCEEDINGS OF THE NEW HAVEN MEETING 



The greatest problems of physical geology, according to Dutton (21), 

 are : First. TVhat is the potential cause of volcanic action ? Second. 

 What is the cause of elevation and subsidence of restricted areas of the 

 earth's surface? Third. What is the cause of the foldings, distortions, 

 and fractures of the strata? 



The first two of these he regarded as being without satisfactory expla- 

 nation, and for the third he proposesd a solution in elucidating his 

 theory of isostasy. After having shown that the contractional hypothesis 

 is quantitatively insufficient and qualitatively inapplicable in explaining 

 the folding of the earth's crust, he presented in a modified form and 

 greater detail the theory propounded many years ago by Babbage and 

 Herschel. It was pointed out that the unloading of the land by erosion 

 and the loading up of the sea floor by deposition resulted in a force which 

 tends to push the loaded sea bottoms inward upon the unloaded land 

 horizontally — a force of the precise kind that is wanted to explain the 

 origin of systematic plication. 



This view of the essentially isostatic condition of the earth, for which 

 he invented the name isostasy, has been in recent years most ably advo- 

 cated, and in fact practically demonstrated, by Prof. John F. Hayford. 2 



Dutton began the study of the volcanic problems early in his geological 

 career, and his first papers in the Geological Survey (4) pertained to 

 volcanic products. In his study of the plateau region he had abundant 

 opportunity to observe an extensive and profoundly interesting series of 

 complete and dissected volcanic as well as plutonic masses. In 1882 he 

 visited the Hawaiian Islands to study Kilauea. Mauna Loa. and the other 

 great volcanoes of that region (12) before beginning his survey of the 

 great volcanic field of northern California and Oregon, where in 1885 he 

 made a special study of Crater Lake and recognized its similarity to the 

 great calderas of Hawaii (18). 



He returned to military duty in September, 1890, and went to Central 

 America and Lake Xicaragua. In 1891, while on duty at San Antonio, 

 Texas, he made frequent excursions to the volcanoes of Mexico. 



In 1899 he was recalled to duty in the office of the Chief of Ordnance 

 in Washington, and on February ?. 1901, at his own request, was retired 

 from active service. 



One of Dutton's most notable contributions to science recognizes grav- 

 ity as an essential factor in causing volcanic eruption. He was much 



2 The figure of the earth and isostasy. Coast and Geodetic Survey report, 1T09 ; also 

 supplementary investigations. Coast and Geodetic Survey Report for 1910. and isostasy, 

 a rejoinder to the article by Harmon Lewis. Journal of Geology, vol. xx ? p. 5G2. Sept.- 

 Oct., 1912. 



