January 1, 1897.] 



SGIENGE. 



11 



at Washington in 1861 while at work upon 

 his final report upon this region, which has 

 consequently never been published. 



To the expedition which explored the 

 middle route across Colorado and Utah in 

 1853, under Capt. Gunnison, who was killed 

 by Indians in Sevier Lake Valley, and 

 through Wyoming, Utah and Nevada to 

 •California, in 1854, under Lieut. Beckwith, 

 Dr. James Schiel was attached as surgeon 

 and geologist. His report and Beckwith's 

 narration contain scattered notes on the 

 geology of the route, but no connected de- 

 scription. 



Jules Marcou, who had come to this 

 -country from Switzerland with Agassiz, was 

 the first geologist to study Western rock 

 formations, who had had a field training in 

 Europe. While his personal familiarity 

 with different geological horizons in Europe 

 enhanced the value of his field determina- 

 tions, it also exposed him to the danger of 

 laying too much stress in correlation upon 

 mere physical resemblance. The route of 

 ishe Whipple expedition, to which he was 

 attached as geologist in 1853-4, followed 

 the Arkansas and Canadian rivers from 

 the mouth of the former to the source 

 of the latter, and thence through New 

 Mexico to Albuquerque ; it then followed 

 in a general way the general route of the 

 Atlantic and Pacific Railroad to Los An- 

 geles. His preliminary report was pub- 

 lished in 1855. He also prepared a diagra- 

 matic section of the country from the Mis- 

 sissippi Valley to the Pacific Ocean ; like- 

 wise a preliminary report upon the route 

 followed by Capt. John Pope further south 

 in Texas, made up from the notes and 

 specimens collected by the latter. His 

 claims as a geological discoverer rest upon 

 the recognition of Carboniferous in Arkan- 

 sas, the Permian and Carboniferous in New 

 Mexico and Arizona, the Trias in Indian 

 Territory, northern Texas and ISTew Mexico. 

 He thought also to have found the Juras- 



sic, Neocomian and Chalk at different locali- 

 ties from New Mexico eastward. The ge- 

 ologists who have examined this field in 

 later years and in greater detail have, in 

 the light of all the geological knowledge 

 that has accumulated since, assigned some- 

 what different ages to the beds described 

 under the latter heads. This does not, 

 however, detract from the value of Mar- 

 cou's contribution to American geology, 

 when one takes into consideration the cir- 

 cumstances under which his work was 

 done and the little that was known of the 

 geology of the West at the time. 



Marcou did not make the oflScial report 

 upon his geological studies. When he was 

 upon the point of embarking for Europe 

 with his notes and collections, in order that, 

 in working them up, he might be able to 

 make comparisons with material in the 

 museums abroad, they were seized by order 

 of Jefferson Davis, then Secretary of War, 

 and he was obliged to embark without 

 them. His material was later worked up 

 and the final report on the 35th parallel 

 made by W. P. Blake, as ofiicial geologist 

 of the expedition. 



Blake's own observations were made as 

 geologist in the expedition, under Lieuten- 

 ants E. S. Williamson and J. G. Parke, in 

 the summer of 1853, to determine the prac- 

 ticability of various routes from San Fran- 

 cisco through southern California to the 

 mouth of the Gila River. The region is 

 not one from which definite geological data 

 could be obtained, the rocks, with the ex- 

 ception of recent and Tertiary formations, 

 being barren of fossils and classed as meta- 

 morphic and eruptive. Eocene strata were 

 recognized near San Diego, and Blake made 

 interesting observations on desert phe- 

 nomena, such as sand-polishing, prevailing 

 west winds, etc. In economic geology he 

 described the auriferous gravels and hy- 

 draulic washings, and concluded that the 

 age of the formation of gold was contem- 



