EESUME OF LITERATURE. 115 



It seems probable that this upper brick-red series is the Wyoming formation of 

 the Denver Basin area, while all the series between it and the Arehean, part of which 

 contains Cai'boniferous fossils, ma}^ be the equivalent of the Fountain formation. 



Because of their stratigraphic position and of the lack of fossil evidence as to 

 the age of the Red Beds (by which term is here designated the upper or " Mesozoic" 

 portion), King, as we have seen, refers them to the Trias." 



Quite recently W. C. Knight* reported the discovery of a Carboniferous fauna 

 in the Red Beds of Wyoming. The locality is near Red Mountain, on the Colorado 

 line, in the Laramie quadrangle, where the King atlas represents the Triassic as 

 overlapping the Carboniferous and resting upon the granite. The horizon is about 

 725 feet above the base of the series, whose whole thickness is given as 1,678 feet. 

 Knight states that the calcareous beds which King maps as Carboniferous a little 

 farther noi'th do not in realit}' underlie the Triassic series of Red Mountain, but, 

 merging into it, are equivalent to its lower portion. He remarks on page 420: 



"Just what proportion of the Red Beds will be equivalent to the limestones has 

 not been determined, but probabl}^ not less than 500 feet of the strata near the Colo- 

 rado line will correspond to limestones and light-colored sandstones some 15 or 20 

 miles to the northward, and possiblj"^ a greater thickness." 



Of the Carboniferous age of the fauna found at Red Mountain it is impossible 

 to enteitain a doubt, but one may not draw from this occurrence any strong 

 inference as to the age of the beds above, of the "Triassic''' series farther north, or 

 of the Wj^oming formation of the eastern flank. A question may well be raised, 

 however, as to the existence of the series consistently called " Triassic V by King 

 and other authors; or, in other words, since the lithologic characters which locally 

 distinguish the Carboniferous and "Triassic" beds break down within so short a 

 distance as 20 miles, leaving the series uniform and indistinguishable, whether 

 there is sufficient evidence to warrant separating 800 feet at the top and placing so 

 important a division line as that between Paleozoic and Mesozoic in the midst of 

 so thin and uniform a series. The consideration of this question is bewildered 

 through the lack of paleontologic data or of refined stratigraphic evidence, of which 

 we have some, but far too little. However, the Red Beds, including the so-called 

 "Triassic," of this general area may prove to be Carboniferous, as suggested by 

 Knight; but a closely similar case may be instanced in, the Rico and Dolores forma- 

 tions of the San Juan region, where fossils seem to demand a division. 



Probabh' the first account of the Paieozoics about Canyon is to be found in 

 Ruffner's report on a reconnaissance in the Ute country, published in 1874."^ 

 Hawn's description contained therein amounts to little more than a mere mention of 



aU. S. Geol. Expl. 40th Par., Rept., vol. 1, 1878, p. 249 



6 Jour. Geol., vol. 10, 1902, pp. 413-422. 



<■ Ruffner'.'j Rept. Recon. in the Ute Country, 43cl Cong., 1st sess., House Ex Doc, No. 193, 1874. 



