CHAPTER XXVIII 

 NEW FIELDS OF WORK IN CALIFORNIA 



STUDIES AND VACATIONS IN THE SIERRA NEVADA, 1903, 1904 



Most of the last 15 years of Gilbert's life were divided between residence in Washington 

 and in California. Parts of four summers, 1903, 1904, 1907, and 1908, were given to studies 

 and vacations in the Sierra Nevada, and many months of the years from 1905 to 1917 — except 

 for detention in the East by illness in 1909 and 1910 — were devoted to the investigation of 

 hydraulic-mining debris, during which numerous visits were made to various mountain districts 

 in the northern half of the State. 



Of the first two summers spent in the mountains, one was with an outing party of the Sierra 

 Club of San Francisco on the High Sierra about the head of Kern River and around Mount 

 Whitney, the other with a friend in the Yosemite district. Gilbert was a delightful companion 

 in the mountains and at the camp fire. His quick grasp of the meaning of natural phenomena 

 made him their proper exponent, his vigor and enthusiasm insured him a hearing, and his humor 

 and good fellowship made him always a welcome addition to any group. He pointed out with 

 inspiring animation the many structures of geologic significance and the varied forms of glacial 

 sculpture to his botanical and zoological friends, and in return listened attentively to their 

 accounts of Alpine plants and animals. It must indeed have been a high privilege to make a 

 mountain excursion with so learned a nature lover. It is worth noting that these trips in the 

 Sierra Nevada appear to have been the first on which Gilbert spent a considerable time in 

 mountains of temperate latitudes at a height where the effects of extensive Pleistocene glaciation 

 were observable close at hand, although he had seen from sea level the effects of much more 

 intense glaciation in the mountains of Alaska on the Harriman expedition a few years before. 

 He had indeed many years earlier detected, apparently by long-distance observation, the signs 

 of local glacial erosion on some of the higher ranges in the Great Basin without ascending them, 

 for in his first Wheeler report he wrote regarding the Schell Creek range : 



The crest is remarkably acute, and is buttressed by lateral spurs, between which are close, hopper-shaped 

 valleys, that once contained very small glaciers (III, 88). 



He had also ascended the eastern face of the Sierra near Mono Lake when inspecting 

 Russell's work there in 1883; and with the memory of observations then made he mentioned 

 four years later, the occurrence of "high level debouchures of low-grade tributary canons" 

 over the deep main canyons by which the eastern face of the range is there incised. He added: 



I am disposed to think that ice may have had much to do with the production of the phenomena. It is 

 manifest that a trunk glacier would greatly exceed a tributary in eroding power, and the conditions of ice erosion 

 do not seem to require any equalization of level at the junction of [glacial] streams. 



This foreshadowed but did not reach a valid explanation of hanging lateral valleys. His 

 experience in Alaska corrected the misapprehension expressed in the last sentence. 



The visits to the Sierra in the summers of 1903 and 1904 enlarged these earlier experiences, 

 and led to the preparation of a number of short essays: "The systematic asymmetry of crest 

 fines in the High Sierra of California," ' in which the asymmetry was explained by the greater 

 strength of glacial erosion on the shaded or leeward slopes where snow was collected in greatest 

 thickness during the Glacial period; also, "Domes and dome structures of the High Sierra," 2 

 "Variations of Sierra glaciers," 3 " Crescentic gouges on glaciated surfaces," " Moulin work under 

 glaciers," "Gravitational assemblage in granite," "Terraces of the High Sierra" and ' Lake 

 ramparts." * These communications all represent relatively small problems, briefly treated; 



» Journ. Qeol., rii, 1904, 579-588; Sierra Club Bull., v, 1904, 279-286. 



' Bull. Geol. Soc. Amer., xv, 1904, 28-36; Sierra Club Bull., v, 1904, 211-220. 



« Sierra Club Bull., v, 1904, 20-25. 



« Bull. Qeol. Soc. Amer., ivii, 1906, 303-316; 317-320; 321-328. Science, ui, 1906, 822. 



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