26 GROVE KARL GILBERT— DAVIS tM " M0,B ^v<£xs£ 



It is only with respect to the plateau province that Gilbert seems to have regarded his 

 studies as fairly satisfactory, and that not so much because he made a prolonged stay there as 

 because of "the simplicity of the structure, the thoroughness of its drainage, which [in contrast 

 with the Great Basin Range province] rarely permits detritus to accumulate in its valleys, its 

 barrenness, and the wonderful natural sections exposed in its canons." There one "can trace 

 the slow lithological mutations of strata continuously visible for hundreds of miles; can examine, 

 in visible contact, the strata of nearly the entire geological series, and detect every noncon- 

 formity, however slight; and can study the simpler initiatory phases of an embryo mountain 

 system." It is well to bear in mind the contrast thus suggested between the simplicity and 

 visibility of the plateau-province structures and the complications and concealments of the 

 basin range structures, when one examines the reports regarding them. 



Gilbert wrote, besides several condensed reports of progress and a number of brief scientific 

 articles on special topics, two final reports, dated July and October, 1S74; the first covered the 

 field work of 1871 and 1872, the second, that of 1873; both were prepared in Washington and 

 appeared in "Volume III, Geology" of the Wheeler survey, dated 1875. The method of 

 presentation originally proposed was largely modified, apparently as a result of Gilbert's prefer- 

 ence for synthetic treatment. An itinerary, which had been planned to record the bulk of the 

 observed facts in the order of their encounter, was omitted except for the barest outlines, which 

 for the first two years are given in a two-paragraph footnote, and for the third year in a half 

 page of text; the systematic treatment was correspondingly expanded. As Gilbert said in the 

 preface to the first report, "General statements have been put for individual, so far as the 

 material would allow"; and again in the preface to the second, "Wherever the facts at hand 

 have appeared to warrant a general statement, that has been given in preference to the indi- 

 vidual facts, in the belief that, even though it shall require future modification, it will be more 

 readily available and in every way of more service to geological science than the enumeration 

 of the local details that were the subjects of direct observations." The preface to the first 

 report also makes generous reference to his associates : 



I have endeavored to acknowledge, in presenting the material, the contributions to it that have been made 

 by gentlemen of the expedition and others; but it is proper to add that these acknowledgments fall far short of 

 expressing my indebtedness to the work of assistants, Messrs. A. R. Marvine and E. E. Howell. The inter- 

 locking of our routes has brought their data into such relation to mine, that all my more general statements 

 are, in part, based upon them. 



Although it may be agreed that narrative records are generally less satisfactory than 

 classified statements for the presentation of scientific studies, one must here regret the loss of 

 first impressions made by the geology and the physiography of regions so extraordinary as the 

 Great Basin and the plateaus on a mind so sensitive to receive them and so keen to analyze 

 them as Gilbert's. 



GEOLOGICAL GENERALIZATIONS AND CONCLUSIONS 



The preceding details concerning Gilbert's first seasons of field work in the West have 

 been given with some fullness, in order to show the conditions under which he was formally 

 launched upon his geological career. A similarly detailed analysis of his first official reports, 



"There is no good ground for the opinions advanced on pages 86 and 81 that the courses of Eanab and Paria creeks were in part determined by 

 antecedent folds, and that the Aubrey cliff as a topographic feature antedates the Grand Cation. 



"The unhappily large number of typographical errors in Part I are due in part to the fact that I was absent in Utah during the proof-reading 

 and did not see the pages until they had been stereotyped. In these few copies that I distribute myself I have corrected many of the errors in the 

 margin. I have also restored in part some words and sentences that were suppressed in the manuscript after it passed from my hands. Certain 

 of the restored passages are necessary to the understanding of the context and others are needed to prevent the impression that I disregarded through 

 ignorance or discourtesy the work of other geologists. 



"I have to regret that I cannot present with these unbound pages the engravings which accompany them in the official issue. I can only hope 

 that my friends who receive this extract will obtain also the complete volume." 



The chief "restored passages" mentioned in the next-to-last paragraph above, are inserted as interleaved printed slips where they belong and 

 will be reproduced in connection with their context on later pages of this memoir. The marginal manuscript corrections are chiefly as follows: 

 Page 41, "basin ranges" is given capital initial letters, as elsewhere; p. 57, 59, 60, "plateau" is similarly capitalized; p. 75, 8 lines from bottom, for 

 Cherty read Aubrey; p. 83, 176, for Monument read Glen; p. 95, 6 lines from bottom, after subaqueous add clay; p. 99, four additional shell species, 

 collected by Hayden in 1870 and identified by Tryon, are added to the five collected by Gilbert; p. 103, for Anodae read Anodonta; p. 109, 116, for 

 San Francisco read Colorado; p. 172, for Cordillera read Basin Range; p. 173, for New Mexico read Dakota; p. 175, after Newberry add and Major 

 Powell; the lower half of p. 183 and four-fifths of p. 183 should be included in the footnote of p. 182; p. 509, 519, after Newberry add Hayden; p. 512 

 7 lines from top, for northward read westward. 



