RECAPITULATION OF PALEOZOIC FORMATIONS. 191 



from 1,000 feet in the Pikes Peak quadrangle, and speculation is permissible as to 

 whether the Fountain formation of Gilbert may not include some portions of the 

 Wyoming series, which appears to have no equivalent in Gilbert's section. His 

 description, however, is more applicable to the Maroon than to the Wyoming forma- 

 tion. The apparent absence of the Wyoming formation in this area is in line with 

 its apparent absence over the southern portion of the Elk Mountains and in the 

 Sangre de Cristo Range. In the Pikes Peak quadrangle to the northwest a consid- 

 erable amount of these beds exists. Cross refers the Fountain beds in this area to 

 the Carboniferous, especiallj^ on account of their resemblance to fossiliferous strata 

 on the Arkansas River, 50 miles to the west. These can be no other than the Arkansas 

 sandstone of Endlich's reports. Cross measures 1,000 feet of these beds. Gilbert 

 recognizes the Fountain formation in the Pueblo quadrangle, and assigns to it a 

 thickness of 2,100 feet. Hills, in the Walsenburg quadrangle, finds a greatly reduced 

 thickness, only 200 feet, the upper half a brick-red sandstone, which he compares to 

 the Fountain formation, the lower half a brown conglomerate, which he compares to 

 the sedimentaries of the Sangre de Cristo Range. Here, agam, it must be the 

 Arkansas sandstone which is meant. Thus the comparison made by Cross would 

 indicate that the Fountain beds were the same as the Arkansas sandstone, while that 

 of Hills would imply that it was a distinct series overlying the Arkansas sandstone. 



The upper division of Hills's Badito formation by its character and position in the 

 section suggests the Wyoming formation, but as that series appears to be absent both 

 from the Sangre de Cristo Range and in the Pueblo and Pikes Peak quadrangles it 

 seems moi-e probable that this brick-red member is only a locally differentiated phase 

 of Fountain sedimentation. The thickness of the Fountain in the Pueblo quadrangle is 

 somewhat startlingly out of proportion to that in the Pikes Peak and Walsenburg 

 districts, but the series with which it is supposed to be equivalent in the Sangre de 

 Cristo Range and in central Colorado attains a thickness of •±,000 to 5,000 feet, and 

 the dili'erence here is probably due to an unconformity with the overlying W3^oming 

 series, of which the marked overlap of the latter is additional evidence. 



The area to the east and south of the Pikes Peaiv quadrangle is likewise 

 disconnected, and the same is true of the series as it appears in the Manitou Park 

 Basin. It occurs again in the Garden of the Gods, where Hayden reports about 1,000 

 feet, and it also exists in Perry Park, though Lee does not discriminate an}' definite 

 thickness there. The great variation in thickness of the Wj'oming formation in 

 different sections in the Denver Basin is probably partly due to undifferentiated 

 masses of Fountain beds included in their basal portions. The Carboniferous series 

 of King, together with the one supposed to be Primordial, apparently is another 

 recurrence of these beds. Taken together the}' measure 850 feet, and the 

 Carboniferous beds carry fossils. 



