478 REPORT OF NATIONAL MUSEUM, 1904. 



southwestern declivity, the cascade which it formed must have surpassed any simi- 

 lar exhibition of nature's forces of which we have knowledge at the present day. 



On page 42 of his report Newberry gave a section of the Grand 

 Canyon, showing the bottom granite overlain by Potsdam sandstone, 

 and this by Silurian (?), Devonian (?■), and Lower Carboniferous (?) 

 rocks, and, finally, Upper Carboniferous limestone. This was the first 

 section of these beds ever published. 



The source of the materials which go to make up the sedimentary 

 rocks of the West, he thought, could not have been derived from the 

 emerged surfaces east of the Mississippi, but were rather "formed by 

 the incessant action of the Pacific waves on shores that perhaps for 

 hundreds of miles succumbed to their power, and by broad and rapid 

 rivers which flowed from the mountains and through the fertile valley 

 of a primeval Atlantis.' 1 The outlines of the western part of the 

 North American continent, to his mind, were approximately marked 

 out by groups of islands, broad continental surfaces of dry land, and 

 areas of shallow water from the earliest Paleozoic times. 



As already noted, a portion of Newberry's return route lay along 

 that previously (in 1853-1854) traversed by Marcou, and it is interesting 

 to note the different views of the two, offered by this opportunity for 

 comparison. Thus Newberry questions Marcou's determination of 

 the age of the formations near Partridge and Cedar creeks, near Bill 

 Williams Mountain, Marcou regarding them as Devonian and Lower 

 Carboniferous (Mountain limestone), while Newberry thought them to 

 be not older than Carboniferous. In like manner Newberry ques- 

 tioned the Permian age of the Canyon Diablo beds, rightly regarding 

 the same as Carboniferous, and the red sandstone overlying this lime- 

 stone as likely to prove Permian or Triassic. The yellow sandstone 

 along the Rio Grande was considered as not Jurassic, but Cretaceous. 



In 1859 Newberry again took the field, this time in connection with 



a topographic party under Capt. J. N. Macomb. The party left Santa 



Fe, New Mexico, about the middle of July and, crossing the Rio 



Grande del Norte, followed up the valley of the River 



Newberry's Work ... . 



with the Macomb Chama, finally leaving it at the dividing ridge between 



Expedition, 1859. J . *,. . , r . , ,, .. , 



the waters of the Gulf of Mexico and those or the 

 Gulf of California. From here they struck across the headwaters of 

 the San Juan River, passing along the southern base of the Sierra de 

 la Plata, and then northerly to the junction of the Grand and Green 

 rivers. Thence the party proceeded southward to the San Juan River, 

 which they followed up as far as Canyon Largo, passing thence down 

 the valley of the Puerco to the old pueblo of Jemez, and thence east- 

 erly back to Santa Fe. The route, it will be perceived, thus covered 



"This report contains several graphic views of the Colorado Canyon from sketches 

 by F. W. Egloffstein, but which have been largely overlooked since the more recent 

 work of Powell, Dutton, and Holmes. 



