110 CARBONIFEROUS FORMATIONS AND FAUNAS OF COLORADO. 



stone is known to have lici'ii prc'ccdcd. It' Loo is correct in placing the Ordo\iciaii 

 licncath the sandstone, Ihe hitter either belongs with the Millsap, as Lee and Feale 

 June it, and is a new eliMnent introdiieed into the formation, or else it represents the 

 Harding sandstone, the Ordovieian limestone in uU probability being the Manitou. 

 This seems to me altogethei' improbable, as the Harding sandstone appears to be 

 wanting north of Garden Park. 



Peale's Trias, of course, is the more or less precise equivalent of Lee's Red Beds, 

 including also the sandstones and conglomerates h'ing above the Millsap limestone, 

 which he places in the Carboniferous. The raison d'etre for the introduction into 

 literature of the name Wyoming appears to have been that it was supposed to be 

 Triassic and of later geologic age than the Fountain formation which Cross provis- 

 ionally referred to the Carboniferous. Although in the Pikes Peak quadrangle the 

 Fountain beds are followed b}- the Morrison formation, east of the Pikes Peak area 

 the Wyoming formation is supposed to intervene. As Perry Park is intermediate 

 between the Denver Basin and the Pikes Peak quadrangle, and as the Red Beds 

 there seem to have the characters of the Fountain formation in the lower part and 

 of the Wj^oming formation in the upper part, it seems not improbable that the dis- 

 tinction made bj' Lee is correct. The Wyoming and Fountain formations and their 

 supposed equivalents in other areas have the appearance of being continuously 

 deposited, but the evidence of overlap here and in the Dolores River region seems 

 to prove that this was not the case. 



The area immediately north of that surveyed hj Peale in 1873 was examined bj" 

 Marvine" the same year. Th's, the Middle Park division, contains no beds referred 

 by him to the Carboniferous or even to the Paleozoic, but as I regard the Red Beds 

 which he maps as, Triassic as possibly Carboniferous in age, his remarks upon that 

 division are germane to our study. The area embraced bv the Middle Park division 

 is included between parallels 39- 30' and iO^ 20' north latitude and meridians lOi"^ i5' 

 and 106° 30' west longitude. It contains three topographic and geologic areas, the 

 plains, the mountains, and the park, but it is onh' in the plains skirting the moun- 

 tains that any of the so-called Triassic beds occur. They are there continuous with 

 the series which Peale describes under the same name, and they extend without break 

 to the northern limit of the Middle Park district. Their occurrence here differs 

 both from the exposures to the north in Wyoming and those to the south in Peale's 

 district in having no recognized Carboniferous beneath, resting directlj' upon the 

 smoothed but uneven surface of the granite. The Red Beds vary in thickness in 

 this area from over 1,600 to 2,000 feet down to 400 feet. The thinnest sections are 

 found a few miles north of Golden, from which point the series thickens rapidh' to 

 the north and to the south. The color is for the most part a dark red, though in 



aV. S. Geol. Geog. Surv. Terr., [Seventh] Ann. Kept., for 1873, 1S74, pp. 83-192. 



