MEMORIAL OF C. W. HAYES 95 



Hayes many years later successfully to apply similar methods of accurate 

 instrumental location of outcrops in determining the detailed structures 

 of oil pools. It appears from examination of notebooks that Eussell him- 

 self undertook the actual measurement of the section, while Hayes's duties 

 were the extending of the mapped area by less precise methods. Hayes's 

 first notebooks show that he applied himself closely to the problem of 

 stratigraphy and structure. It was natural from his training that his 

 mineralogical notes should be more detailed than those usually taken by 

 stratigraphers. 



The following winter was to be the first of many spent by Hayes in 

 Washington. It appears that the summer's field work had not yielded 

 enough material to keep the assistant entirely occupied. He was there- 

 fore assigned to various duties, including bibliography, mineral statistics, 

 and the installation of an exhibition of fossils at the N'ational Museum. 

 Hayes's intimate association with Eussell (for he was a member of his 

 household at this time) was an important influence in developing in the 

 young assistant an interest in the broad problems of geology. 



The plan for solving Appalachian structure by detailed cross-sections 

 was reported in 1887 by Major Powell to have been ^^eminently satis- 

 factory." Those who had actually taken part in the field-work appear 

 to have been less sanguine of the value of results achieved. As a matter 

 of fact, the plan for detailed cross-sections soon gave way to areal map- 

 ping, which was found to be the only method to unravel the stratigraphy 

 and complex structure. In 1888 Russell with great pleasure relinquished 

 his claim to the southern Appalachians as a field of research, and it fell 

 to Hayes to bring the work to definite conclusion. 



Study of overttii{Ust Faults 



Trained both in mathematics and in the exactitude of tlie chemical and 

 physical laboratory, Hayes applied, so far as practicable, tlic sauie pre- 

 cision to geologic field problems. His standards of accuracy, both of 

 observation and record, were more refined than tliose tlien generally ac- 

 cepted. Though other American geologists liad made (letail('<l geologic 

 maps, Hayes and his colleagues of the iVppalachian Division must he 

 recognized as leaders in the modern epoch of jDrecise geologic map])iMg. 



The difficulties of solving the structures and stratigraphic sequence in 

 this field were much enhanced because the standard for base ma])s was 

 then not high. Maps which would be sufficiently accurate for delineating 

 the larger stratigraphic units utterly failed to serve for the precise map- 

 ping undertaken. In other words, the standards of geologic mapping had 

 improved to a far greater extent than had those of topographic surveys. 



