EESUME OF LITER ATTJEE. 81 



quartzite combined. The thin, dark-colored limestones, interbedded with shales and 

 sandstones, which overlie bed 68, apparently belong to the Weber shale, though pos- 

 sibly they should be referred to the Leadville limestone. At all events, bed 38, with 

 its well-marked Upper Carboniferous fauna, must be higher than the Leadville, and 

 perhaps represents the upper limit of the Weber shale, for immediately^ above occur 

 some coarse sandstones, pretty well interstratified with limestones, it is true, which 

 seem more characteristic of the Weber grits. Less than 2,000 feet of Weber grits 

 then follow, after which there is a repetition of the basal portion of the section. 

 Beds 11 to 19 are again the Potsdam, as pointed out b}' Peale, and belong to the 

 Sawatch quartzite. This formation seems here to have a thickness of only 110 feet, 

 while Peale points out that in Mosquito Gulch the thickness is 160 feet and in 

 Buckskin Gulch over 200. The average thickness of the Potsdam group along this 

 range he believes to be about 150 feet and the remainder of the Silurian about 200 

 feet. The rest of the section, consisting of about 230 feet, probably belongs in the 

 Yule limestone, unless bed No. 2, consisting of 30 feet of blue limestone, belongs to 

 the Leadville. 



In describing his observations made during the field season of 1875 Peale devotes 

 considerable space to comparisons and a summary," in the course of which he gives a 

 generalized section of the Carboniferous series of the Park Range for comparison 

 with that made out for the region of the Dolores River. This generalized section, 

 which seems to be in large measure made up from the earlj' sections, No. 9 and No. 

 IS, I will quote as follows: 



Generalized section in the Park Range west of South Park on Foiinnile Greek, district of 1873. b {After Peale.) 



PERMIAN. 



Feet. 

 Ked, pink, and maroon-colored sandstones, gypsiferous and calcareous, with limestones in tliin 



beds. No fossils 2,000-2,500 



COAL MEASURES. 



Conglomeritic sandstones, green and gray micaceous sandstones and shales, bluish limestones, and 

 interlaminated sandstones. Fossils, from below — Second layer: Producius nebraskensis, Pro- 

 ductus prattenianus, Productus semirelicidatus, Sjnrifer ojnmus, Pleurotomaria taggarti. First 

 layer: Productus, Spirifer, Trilobites 2. 000 



SUBCAREONIFEROUS. 



Blue limestones and sandstone shales, limestones predominating; fossils are indistinct 300— tOO 



Total ■ 4,300^,800 



aU. S. Geol. Geog. Surv. Terr., Ninth Ann. Rept., for 1875,1877, pp. 70-79. 

 fcSee section No. 18, p. 229, report 1873. 



14364— No. 16—03 6 



