RECAPITULATION OF PALEOZOIC FOKMATIOWS. 187 



of variegated beds of sandstones of various textures alternately with layers of arena- 

 ceous flay. The entire thickness was estimated at a,bout 1,000 feet. It is most 

 probable that these beds are Carboniferous."" The beds on Eagle River with which 

 Hayden compares this series (section 23, p. 244) form part of the Maroon formation. 



South of Colorado Springs the Paleozoics and Red Beds are concealed for a short 

 distance by Cretaceous overlap, but the Hayden atlas represents a considerable tract 

 of Triassic and Silurian across the southern end of the Colorado Range, north and 

 northeast of Canj^on. Much of this area is included in the Pikes Peak quadrangle, 

 where Cross recognizes two Carbonifei'ous formations, the Millsap limestone and 

 the Fountain formation, intervening between the Ordovician Fremont limestone and 

 the Morrison formation of Jurassic age. The Millsap limestone is probably included 

 under the "' Silurian" color, the Fountain beds being the Triassic and the Morrison 

 the Jurassic of the atlas. The conditions here would then be the same as I have 

 supposed them near Colorado Springs, with the "Triassic" or Wyoming beds absent 

 beneath the Morrison. Nevertheless, east of the Pikes Peak quadrangle this series 

 is supposed to reappear above the Fountain formation. 



The Millsap limestone is, of course, of Mississippian age and has been considered 

 in -the appropriate section. Cross's definition of the Fountain formation applies alike 

 to the outcrop in Gai'den Park in the southern part of the quadrangle and to those 

 in the northeastern part which connect with the exposures in Manitou Park north of 

 the area. This consists of a series chiefly of coarse-grained, crumbling, arkose 

 sandstones in hea^y banks, locally conglomeratic and mottled with gray and various 

 light shades of red. Near the base and at intervals throughout the series are very 

 dark-red or purplish layers of arenaceous shale or fine-grained sandstones. The 

 thickness is about 1,000 feet. No fossils were found by Cross, from whose descilp- 

 tion the facts noted above were derived, but the formation was referred by him to 

 the Carboniferous, because of a similarit}' to the Arkansas sandstone, of known 

 Carboniferous age. The beds overlying the Fountain formation are the Morrison 

 formation, the same series by which the Wyoming formation is followed in the 

 Denver Basin. East of the Pikes Peak quadrangle, however, another series resem- 

 bling the Wj'oming comes in above the Fountain formation, intervening between it 

 and the Morrison formation. Because the Fountain formation seems to represent 

 a distinct series underlying the Wyoming beds, the name "Wyoming" was 

 introduced for the younger series in the Denver Basin monograph. At the same 

 time I suspect that in local sections part of even the typical Wyoming is equivalent 

 to the Fountain. Hayden also regarded this series as distinct from the Red Beds, 

 as indicated in the passage quoted above, which, however, refers to the exposures 

 west of Colorado Springs. 



aV. S. Geol. Geog. Surv. Terr., [Eighth] Ann. Rept., for 1874, 1876, p. 42. 



