116 GROVE KARL GILBERT— DAVIS [MEMOI Vouxxt 



had supplied. An exploring expedition was therefore planned in 1875; and as its object was 

 related "specially to the right and interests of the Sioux Indians," it was placed under the 

 Bureau of Indian Affairs of the Interior Department — thus adding still another independent 

 survey to a list of such organizations that was already too long. Jenney was appointed geolo- 

 gist in charge and one of his assistants was Newton, whose name has already been mentioned 

 as a member of the Ohio Geological Survey during Gilbert's association with it. The expedition 

 set out over the plains from Cheyenne, Wyo., in May, 1875, with two companies of Infantry 

 and six of Cavalry, 400 men in all, and 75 wagons, and returned there in October. 



Jenney promptly prepared a report on mineral resources, which was published in 1876 and 

 republished in the volume here considered. Newton also prepared a report at once, and spent 

 a considerable sum of his own money on it, but when presented to Congress for publication it 

 encountered "a selfish and heartless opposition . . . springing from the fear that it would 

 betray the inaccuracy of previously published descriptions of the geology of the region"; such 

 was Newberry's view, expressed in a biographical sketch of his former student and associate 

 at the beginning of the volume, of the rivalry and jealousy felt at that time by one governmental 

 survey for another. By reason of the delay thus caused Newton returned to the Black Hills 

 in 1877 to revise and extend his previous work, and especially to settle certain questions that 

 had arisen while he was engaged upon his report; and while there he died of typhoid fever at 

 the age of 32 years. His manuscript, chiefly in the form of a first draft, was left incomplete, 

 with much erasure and interlineation. Its revision for publication was intrusted to Gilbert, 

 who " therefore felt called upon to put himself, in a certain sense, in the place of the author, 

 and make such emendation of form as seemed necessary to harmonize the whole." He "freely 

 modified the language" in such ways as he conceived the author might have done had he sur- 

 vived ; but except for a correction regarding the source of placer gold, the substance was care- 

 fully preserved. 



There was, however, a section of the report on the "Structure and age of the Black Hills," 

 indicated by title in Newton's table of contents but unwritten; and the whole of this section 

 was therefore composed by the editor. "All the data are Newton's, and so are all the principal 

 deductions except those derived from the drainage system"; these are Gilbert's and they 

 are truly Gilbertian in their directness and lucidity. The main body of the report is a straight- 

 forward account of the geological formations involved, beginning with the Archean and ending 

 with the Tertiary and volcanic rocks; and it is worth noting that Gilbert, who in his own 

 reports had followed the rule in text and in tabular statement of beginning with the younger 

 or higher formations and ending with the older or lower, here appears to have followed Newton's 

 preference of beginning with the oldest formations and proceeding in time sequence, even to 

 the point of tabulating some of the detailed sections upside down. 



PHYSIOGRAPHY OF THE BLACK HILLS 



The 20-page section that Gilbert wrote is essentially a discussion of physiographic geology. 

 Although it still bears Newton's title, "Structure and Age of the Black Hills," its first sentence 

 reads : 



It remains to consider the origin of the topographic forms which constitute the Hills. How and when 

 did the plateaus, and peaks, and cliffs, and canons, and valleys that make up its topography come into exist- 

 ence? The answer to the question is, in general terms, that the rocks were uplifted, and that being uplifted 

 they were by the processes of erosion worn away and carved into the forms we have seen (203). 



A restoration of the original uplift, as if unworn, was first attempted; thus reconstructed, 

 it would have been a flat-topped dome, like the Uinta Moimtains or the Kaibab Plateau, of 

 oval outline, 70 by 40 miles in diameter, 6,600 feet above the surrounding plains, with lateral 

 slopes having declivities of from 15° to 90°, and with a total volume of 4,200 cubic miles. The 

 ideal form was, however, not realized, because much erosion must have been accomplished 

 during its progress, and because "upon no plausible theory of mountains can it be supposed 

 that their birth-labor is other than exceedingly slow. The earthquake is but the passing pang 

 that records a unit of progress; it is only by the combination of many such units, separated 



