January 1, 1897.] 



SCIENCE. 



13 



Cretaceous and Tertiary. Along a great 

 part of the front of the Eocky Mountains 

 and around the Black Hills was a strip of 

 Upper Carboniferous and Upper Silurian 

 separating the Cretaceous from the meta- 

 morphic nucleus. Likewise, along the face 

 of several New Mexican ranges, in spots 

 around Salt Lake and in the neighborhood 

 of San Francisco Mountain, the Upper Car- 

 boniferous was represented. With this ex- 

 ception all the Western mountain region 

 was indicated as metamorphic or unknown, 

 as far as the Pacific Ocean, except for large 

 areas of igneous and Quarternary in 

 northern California and Oregon. 



1857. To the expedition of Lieutenant J. 

 C. Ives, sent out in the autumn of 1857 to 

 explore the Colorado River from its mouth 

 up to the head of navigation, Dr. J. S. 

 Newberry was attached as geologist. A 

 quarto report of this expedition was pub- 

 lished by the government in 1861. 



In this report Dr. Newberry summarizes 

 the work that had been previously done in 

 California, and makes the uplift of the 

 Coast Ranges post-Miocene and probably 

 later than the Sierra Nevada. His obser- 

 vations on the region of the Canyon of 

 the Colorado are those of a trained geol- 

 ogist, and show a grasp of the broad con- 

 ditions of structure of the Rocky Moun- 

 tains much in advance of any previous ob- 

 servers. His published section of the rocks 

 of the Grand Canyon, though not based in 

 every instance upon direct lithological evi- 

 dence, has not been essentially modified or 

 improved by later observers up to the time 

 of Walcott's investiation under the present 

 Survey. The Algonkian formations be- 

 tween the Silurian and Archean do not 

 occur in the region examined by him. 



His general views on the structure of the 

 mountains are seen in the following quota- 

 tion (Ives Report, p. 47) : 



" This much we can fairly infer from the 

 observations already made on the geolog- 



ical structure of the far West, namely, that 

 the outlines of the western part of the North 

 American continent were approximately 

 marked out from the earliest Paleozic times; 

 not simply by areas of shallower water in an 

 almost boundless ocean, but by groups of 

 islands and broad continental surfaces of 

 of dry land." 



This remark was in opposition to the then 

 generally received theory that the area of 

 the Rocky and California mountains was 

 till the Tertiary period occupied by an open 

 sea. 



1859. As geologist of the Macomb ex- 

 ploring expedition to the junction of the 

 Grand and Green Rivers, Dr. Newberry col- 

 lected much additional data on the geology 

 of the plateau country. His report on the 

 geology of the country, accompanied by a 

 beautifully shaded topographical map made 

 by Baron F. W. von Eggloifstein, was de- 

 layed by the confusion attending the Civil 

 War, and was not published until 1876. It 

 contains the following important additions 

 to the geological knowledge of the region : 



First, the determination of the Triassic 

 age of the red sandstone by plant remains 

 found at the copper mines of Abiquiu, New 

 Mexico (Marcou's determination had been 

 based on lithological evidence alone) ; 

 second, the tracing of Upper and Middle 

 Cretaceous formations along the south 

 flanks of the San Juan into the upper Col- 

 orado Basin, and making a section of 6,000 

 feet of rocks from the Carboniferous to 

 Cretaceous, inclusive ; third, the finding of 

 Saurian remains in the Canyon Pintado in 

 the beds below the No. 1 Cretaceous, which, 

 doubtless, represent the Atlantosaurus beds, 

 since made famous by Marsh. Finally, al- 

 though he only skirted around the isolated 

 laccolitic mountains of that region, he 

 shows a remarkable prescience in his re- 

 mark upon the Sierra Abajo, that it has the 

 appearance of a trachytic core pushed up 

 through and uplifting Cretaceous strata. 



