RESUME OF LITEEATUEE. 45 



probabl}' be Algonkian, and the Uinta sandstone would represent the pre-Carbonifer- 

 ous quartzites of the Wasatch section. The Mississippian portion of the Wasatch 

 must needs be absent and not represented by Powell's Red Wall, as is involved in 

 his correlation of the Uinta bed with that in the Grand Can_yon region, because 

 Pennsjdvanian fossils were found immediately above the Uinta sandstone, as pre- 

 viously noted [Spiriferina henhickyensis^ Seminula siMilita, and Meekella striaticos- 

 tatii found near Ute Peak in the eastern portion of the range). As opposed to this 

 might be urged the very I'apid diminution in bulk, which the Uinta series, which 

 seems in full force in the east end of the range, must undergo to find its equiva 

 lence in the realh' insignificant thiclcness of pre-Carboniferous sedimentaries of 

 central Colorado. There is also the faunal evidence, verv slender but not to be 

 overlooked, which would tend to assign the upper portion of the Uinta sandstone to 

 the Carboniferous (and if so, doubtless to the Upper Carboniferous) ; and the difficulty, 

 in view of the correlation of the other Uinta and Wasatch formations sanctioned by 

 hy both stratigraphy and paleontology, of accounting for the Weber quartzite, which 

 reallj^ has no lithologically similar correlate in the section of the eastern Uintas 

 except the Uinta sandstone. 



A third hypothesis is also possible, and on the whole it seems to me to possess 

 more advantages than the two others. It has been shown that the Mississippian 

 portion of the Wasatch limestone exists, with its characteristic fauna, in the western 

 end of the Uinta Range, and that it there separates two quartzite series of ver}' 

 different geologic ages, but lithologically so alike that they were in one instance at 

 least mistaken for one another. If the Wasatch limestone were renioved it is 

 evident that these two formations would come in centact, and would form a series 

 whose members it would l)e difficult to distinguish, except by most ca,reful scrutinj'. 

 To suppose, then, that the upper part of the Uinta sandstone represents the Weber 

 formation, and the lower the pre-Carboniferous, chiefly Cambrian, quartzites of the 

 Wasatch section, would account for the correlation by King of the Uinta sandstone 

 and overlying Carboniferous series with the Weber quai'tzite and Upper Coal 

 Measures of the Wasatch section, for the probable occurrence of Carboniferous 

 fossils in the upper portion of the Uinta formation, for the probable thinning of the 

 Cambrian in its eastern transit into Colorado, and for other observed facts which 

 have a bearing upon this problem. 



The faunal evidence is indecisive for any hypothesis, and' is not conclusively 

 favorable to that last advanced. As previously pointed out, the very scanty fauna 

 so far obtained from the Uinta sandstone indicates that its upper portion is of Penn- 

 sjdvanian age, and tends to corroborate the correlation by stratigraphy of that portion 

 at least with the Weber quartzite. From the Upper Coal Measures, using King's 

 term, of the Uinta Mountains but little paleontologic evidence exists. In the 



