KESUME OF LITERATURE. 87 



limestone or with the Weber limestone. In the other section th^ Leadville seems 

 to consist of a lower series of graj^ limestone, an upper one of dark-blue limestone, 

 and an intermediate one of shales. A certain resemblance to this series will be 

 observed in the Fossil Ridge section, though the latter contains some overlying 

 shale and limestone which appear to be without equivalent in the other. 



Intermediate between the Yule and Leadville limestones at Fossil Ridge occur 

 80 feet of yellow and gray shale and 175 feet of variegated shale and limestone. The 

 former especially seems to resemble in thickness and character the upper member of 

 the original Yule limestone, which Spurr correlates with the Parting quartzite, but 

 the other and heavier bed may possibl}' belong to the same series. In the South 

 Park section Endlich describes a white, yellow, and pink quartzite and red sand- 

 stone as occurring just above the Yule, followed by yellow and brown shale and light- 

 yellow and graj" shale. The quartzite is not represented in the Fossil Ridge section, 

 but is suggestive of the original Parting quartzite in character and position. The 

 overlying shales have more the character of the Parting formation of the Elk 

 Mountain region. The circumstances thus detailed suggest the possibility that the 

 Parting beds, as identified at different localities, are of a dual character, consisting 

 of quartzites below and variegated shales above, the shales alone being found in the 

 Elk Mountain region, the quartzite alone at Leadville, both shale and quartzite in 

 Endlich's section, and neither shale nor quartzite at Red Clitf. At all events, this 

 formation apf)arentlj' varies considerably from point to point both in character and 

 thickness. 



South of the point at which the preceding section occurs, according to Endlich, 

 the Silurian retains its characters, the quartzitic limestone resting directlj^ upon 

 granite, and at a point designated bj' him as station 56 another section was taken 

 across the same line of outcrop. 



This station I have been unable to locate exactlv, but it appears to be situated 

 southeast of station 53 and not far to the west of the more northerly traussection by 

 Badger Creek of the Paleozoic outcrop. The stratigraphic succession at station 56 

 consists of the following members: Resting upon porphyritic granite are found a 

 series of A'ellow to light-brown, hard quartzites, followed by fine-grained white and 

 pink quartzites, and covered b}' shales that can be referred to the Carboniferous. 

 Endlich suggests that the lilue limestone which formed the base of the other section 

 underlies the quartzites, although it was not found at this point. The continuation 

 of this section also appears to be found upon page 311 of Endlich's report. ' ' 0ver- 

 lying," he says, "the yellowish shales, interstratified with quartzites, which have 

 been referred to the Upper Silurian, are a series of blue limestones, irregularly alter- 

 nating with gray shales containing Orthis and crinoids." On page 309 of his report, 

 however, the yellowish shales are not referred to the Upper Silurian but to the Car- 



