CORRELATION OF FORMATIONS 491 



In the Pikes Peak folio, issued in 1894, the writer established the 

 Fountain formation to include about 1,000 feet of coarse, reddish arkose 

 sandstones, grits, and conglomerates, occurring in the small interior basin 

 of Manitou park and the corresponding beds, with which they were 

 once connected, in the foothill belt at Manitou and the Garden of the 

 Gods. The latter apparently embrace the strata called Carboniferous 

 by Hayden. I also assigned to the Fountain formation the Red beds of 

 the Canyon City embay ment, and Gilbert (Pueblo folio) did the same 

 in 1897 for a small isolated area to the south, occurring in the Pueblo 

 quadrangle. Gilbert, however, provisionally assigned the Fountain beds 

 to the " Jura- Trias." 



My reference of the Fountain formation to the Upper Carboniferous 

 (Pennsylvanian) was in the belief I still hold that its most plausible cor- 

 relation is with the strata of similar character, except for thin limestones 

 exposed in the folded section crossing the Arkansas river below Salida. 

 In the limestones of this section Eldridge once obtained a few Pennsyl- 

 vanian fossils, afterward lost and hence not considered in Girty's review 

 of the Colorado Carboniferous faunas (15). These strata form some part 

 of the indefinite aggregate called the "Arkansas sandstones " by Endlich, 

 and they extend south into the Sangre de Cristo range, where fossils 

 were found sparingly by Endlich and other early explorers. Curiously 

 enough, Endlich did not discuss any possible connection of the Arkansas 

 sandstones with the rocks near Manitou called Carboniferous by Hayden. 



A remnant of Carboniferous beds occurs at the south end of the Green- 

 horn range, and this has been called the Badito formation by Hills (22). 



The base of the Fountain Red beds in the Pikes Peak quadrangle is a 

 plane of more or less pronounced unconformity with lower formations. 

 The whole of the formation is not preserved in that quadrangle, owing 

 to either Mesozoic or Recent erosion, but in the section on and near 

 Fountain creek, below Manitou, it is plain that the natural lithologic 

 limit of the Fountain is a light colored, tine grained, quartzose sand- 

 stone well shown in the Garden of the Gods. This sandstone is appa- 

 rently equivalent to the " Creamy sandstone " of the Denver region, as 

 Darton has pointed out (7). 



In the Denver monograph Emmons and Eldridge (11) named the 

 entire Red bed section of that district the Wyoming formation, distin- 

 guishing within it the lower and upper divisions, on purely lithologic 

 grounds. The Lower Wyoming embraces beds like the Fountain in 

 lithologic character and, in addition, the quartzose Creamy sandstone. 

 Both Emmons (11) and Darton (7) have recognized the resemblance of 

 the red arkose strata of the Lower Wyoming to the Fountain beds ; but 

 the suggestion of the latter (7) that the Fountain and Lower Wyoming 



