Schuchert — Carboniferous of Grand Canyon of Arizona. 347 



Art. XXII. — On the Carboniferous of the Grand Canyon 

 of Arizona; by Charles Schuchert. 



[Contributions from the Paleontological Laboratory, Peabody Museum, 

 Yale University, New Haven, Connecticut, U. S. A.] 



For eight clays in the month of September, 1915, the 

 writer had the greatest scientific pleasure of his life in 

 that geological wonderland, the Grand Canyon of the 

 Colorado River in Arizona. Here may be studied in 

 greater detail than anywhere else strata of marine, 

 brackish-, or fresh-water origin, and even of eolian 

 making; of the deeper seas and of the littoral; of wet 

 and of semi-arid climates ; sandstones, shales, limestones, 

 and dolomites in great masses, and all in their natural and 

 acquired color glories. Of disconformities there are 

 many, and for miles in either direction one may trace two 

 grand unconformities in such continuous detail as can be 

 seen nowhere else. Finally, there are many vertical 

 faults to be seen here, and they are as plain as in any 

 geologic text-book. Think of a vast basin of sedimentary 

 accumulation transected by a series of wide canyons a 

 mile deep and hundreds of miles long. Truly such a 

 geological insight into the structure of the earth's outer 

 shell is nowhere else to be had. Here should be sent all 

 stratigraphers to get their first lessons in sedimentation, 

 for here one follows the formations mile after mile and 

 notes in detail how the sediments are changing and what 

 has been the work of the waters of the sea and land, and 

 of the atmosphere. It is paradise for the stratigrapher 

 studying the strata in mass or in detail, but he will soon 

 learn that it is an earthly paradise, for it is fatiguing to 

 climb its enchanting walls. His thirst for knowledge is 

 constantly being quenched by the results attained, but his 

 throat continually longs for water in the hot and dry 

 atmosphere. Again it is an earthly paradise, for here, 

 even though the strata are in the main of marine origin 

 and visible for every foot of their extent, one looks almost 

 in vain for the "medals of creation." Each dav a few 

 are gotten, but at all places beneath the brink they are 

 few in number and usually poor in preservation. It is 

 the land of paleontologic hopes and the scenery is so sub- 

 lime that one is everlastingly pushed on and on, strug- 

 gling onward and upward to the crag where the fossils 



