44 



SCIENCE. 



[N. S. Vol. V. No. 106. 



three, but ultimately five of such blocks 

 were surveyed. 



The party rendezvoused in California in 

 the early part of the summer of 1867, and 

 commenced work at the east base of the 

 Sierra Nevada in August of that year, with 

 J. D. Hague, Arnold Hague and S. F. 

 Emmons as geological assistants to Mr. 

 King. The following winter was spent in 

 Virginia City in a studj^ of the Comstock 

 lode, where the mines, then about 1,000 feet 

 deep, had alrea^j^ produced 100 millions of 

 dollars. In the following year the work 

 had become more systematized, and, by 

 parcelling it out in several parties each 

 consisting of a geologist and topographer, 

 by the close of an unusually long season it 

 had been carried entirely across the Great 

 Basin to the western shore of Great Salt 

 Lake. In 1869 the remaining desert ranges 

 of Utah, the great Wasatch Range and 

 the western end of the Uinta Mountains 

 were surveyed. This completed the work 

 of the Survey as originally planned, and the 

 party was then located at New Haven for 

 the purposes of working up their large col- 

 lections of rocks and fossils and platting 

 their notes both geologic and topographic. 



Mr. James D. Hague had detached him- 

 self from the field parties in 1868 to make 

 a special studj' of the mining districts, and 

 the result of his work, with some contribu- 

 tions from other members of the party, was 

 published in 1870 as Vol. III. of the Sur- 

 vey reports, entitled 'Mining Industry.' 

 The most important part of this volume is 

 the elaborate study of the great Comstock 

 lode, which has served as a model for all 

 subsequent monographic studies of min- 

 ing districts in this country, the only 

 country in which sucli work has been 

 done. In Chapter VII. of this volume, 

 on the Green River coal basin, Mr. King 

 defined the stratigraphical position of the 

 coal-bearing rocks as undoubtedly Creta- 

 ceous, and gave a bi-ief preliminary sketch 



of the general geological column as de" 

 veloped in the Wasatch Mountains, which 

 he estimated as 56,000 feet in thickness 

 below the Cretaceous. 



Stratigraphical work in Nevada and Utah 

 among the isolated mountain ranges, subse- 

 quently designated by Gilbert as the Basin 

 Range system, was exceptionally difficult 

 because these ranges were separated from 

 each other by valleys 10 to 15 miles in 

 width covered with an unknown depth of 

 Quaternary detritus. Thus no stratigraph- 

 ical sequence of rocks could be carried from 

 one range to the other, and until the Wasatch 

 Range was reached there was practically 

 no starting point for the geological column, 

 for most of the fossils collected were of new 

 species, and their horizons could only be 

 finally determined after a long comparative 

 study. 



Work at New Haven was abruptly inter- 

 rupted in midsummer of 1870 by telegraphic 

 orders from Gen. Humphrej^s to take the 

 field at once, as Congress, without solicita- 

 tion from any one, had passed the usual 

 appropriation to continue the field work. 

 As it was then too late to get together the 

 necessary outfit for a campaign in the high 

 mou^ntain regions to the east of the Wasatch, 

 the work of that season was devoted to a 

 study of the extinct volcanoes of the Pacific 

 Coast, which were apportioned, Mt. Shasta 

 to Mr. King, Mt. Hood to Mr. Arnold 

 Hague, and Mt. Rainier to myself. This 

 work was interrupted by the winter snows, 

 and, as Gen. Humphreys decided that the 

 connection of these mountains with the 

 40th parallel was too remote to admit of its 

 being taken up again, the only immediate 

 fruit of the summer's geological campaign 

 was a paper in the American Journal of 

 Science (June, 1871), announcing the dis- 

 covery of active glaciers on their slopes, 

 the first then known within the boundaries 

 of the United States. 



In the summers of 1871 and 1872 the 



