Ward — Geology of the Little Colorado Valley. -±03 



light of information thus obtained, I studied the various rem- 

 nants of the Mesozoic that are scattered over the Colorado 

 Plateau, and especially Red Butte, which is the most con- 

 spicuous and best known of these remnants. Finally, as a con- 

 cluding task, I returned to the upper portion of the valley of 

 the Little Colorado and made a study of the formation there 

 similar to that which I had made below. 



I will not introduce here the details of this investigation and 

 shall be obliged to omit a great amount of important data, 

 including many sections recorded in my note-book, but I will 

 merely give the most general and essential results and the 

 general section. 



First of all, let me say, that I think I have succeeded in 

 dividing the formation into three entirely distinct series or 

 classes of deposits. One of these, the thickest of them and 

 the one which is best known, has already been named by 

 Major Powell the Shinarump.* This, however, occupies the 

 central portion of the beds in their geological sequence. The 

 other two divisions are, so far as I am aware, unnamed and I 

 have ventured to give names to them. The lower beds I, 

 therefore, designate as the Moencopie beds, from having first 

 found them in their full development at the mouth of the 

 Moencopie Wash. To the other or highest of the series I have 

 thought it appropriate, from the considerations already set 

 forth, to give the name of Painted Desert beds.f 



The Moencopie Beds. 

 These occupy the lowest portion of the formation, having a 

 maximum observed thickness of between 600 and 700 feet. 

 They present several distinct phases, but the greatest part of 

 them consists of dark reddish brown, soft, laminated, argil- 

 laceous shales, nearly destitute of silica, highly charged with 



* Geology of the Uinta Mountains, etc., 1876, pp. 68-69. See Twentieth Ann. 

 Rep. U. S. Geological Survey, Pt. II. p. 318. 



fThe name "Fainted Desert" occurs, apparently for the first time, in the con- 

 tents to Chapter ix of Part I of Lieut. Ives's Report upon the Colorado River 

 of the West, pp. 15 and 113. but is not used in the description of the desert on 

 pp. 116-117, from which the above extract is taken. It is used by Dr. Newberry 

 in Part III, on pp. 76-83, and to it he devotes a section. These early uses of 

 the term show that it refers to an area lying opposite to the region between 

 Wolf's Crossing and Winslow, but Dr. Newberry says (p. 76) " that the peculiar 

 physical aspect and geological structure of the Painted Desert prevail over a 

 wide belt of country bordering the Little Colorado on the east, and extending at 

 least as far northward as our Camp 73." This camp appears from the very 

 imperfect map accompanying the report to have been about on the latitude of 

 Tanner's Crossing, but far to the westward. On this map the Painted Desert is 

 represented as occupying all that region lying along the southwestern base of 

 the painted cliffs from the line of their route through the gap at Blue Peaks and 

 Pottery Hill northwestward to an indefinite distance. On the latest Land Office 

 maps, however, it seems to be restricted to that portion of the desert lying north 

 of the Moencopie Wash and along the base of Echo Cliffs. There seems to be no 

 good reason for thus restricting it. 



