112 



GEOLOGICAL SURVEY OF THE TERRITORIES. 



a separate position here. Calciferous rocks were first recognized- in the 

 Eocky Mountains in 1869 and 1870. Iq 1869 Professor Hayden obtained 

 fossils from near Colorado City, of which Professor Meek says, in the 

 Eeportof 1870, page 287 : " So far as these few fossils warrant the ex- 

 pression of an opinion respecting the age of the rock from which they 

 were obtained, I should be inclined to place it nearly on a parallel with 

 the Calciferous division of the Lower Silurian." Prof. ¥. H. Bradley, in 

 1872, recognized the Quebec group in Utah and Idaho. The series consisted 

 of limestones underlaid by glauconitic sandstones. The limestones were 

 mostly thin and containefl interlaminated shales. The same year Dr. 

 Hayden discovered beds of the same age in Montana, near Gallatin City. 

 There we had layers of limestone also underlaid with glauconitic sand- 

 stones. In 1873 I found near Trout Creek, in Bergen ]?ark, Colo., pink 

 laminated limestones underlaid with glauconitic sandstones. In them I 

 found fossils referred by Professor Meek to the Quebec group. Anal- 

 ogous beds had been seen in Glen Eyrie, where Professor Hayden, 

 in 1869, found a few forms that were referred to the same group. I 

 obtained a few indistinct fossils there in 1873. On Eagle Eiver, above 

 the white quartzite, that has been already treated of as belonging to 

 the Potsdam group, we have glauconitic sandstones and quartzites that 

 lie below a bluish limestone. No fossils were found here, and I refer 

 the beds simply on the lithological evidence as in the following table : 





TEOTJT CKEEK, 1873. 



POUR MILE CREEK, 1873. 



EAGLE RIVER, 1873 AND 

 1874. 





Gneiss. 



Gneiss. 



Gneiss. 



'c3 



Yellow sandstone. 



White quartzite. 



White quartzite. 



a 

 (5 



Pinliisli sandstone. 



Reddish quartzite. 





■ Dark purplish sandstone. 



Quartzites with shales, glau- 

 conitic near the base. 



Glauconitic sandstone. 





Green sandstone. 



Quartzite. 



o 



These beds are glauconitic. 



Quartzitic conglomerate. 



o 



Blood-red calcareous sandstone 

 with Lingulepis and Obolus. 



Blueisli limestones with layer 

 of quartzites near base, con- 

 taining fragments of Euom- 

 phalus and Orthis desma- 

 pleura. 







Pink limestones, containing 

 Orthis . desmopleura, Cojiuco- 

 n/phe, Asaphus, Euomphalus, 

 Iiingula, Bathyurus, and Para- 



■ doxides or OlcnUs. 



Light bluish limestone. 



It will be observed that the order of the section on Trout Creek is ob- 

 served in the other sections. Instead of sandstone, resting on the 

 gneiss, we have quartzite, which in all of the sections is followed by 

 beds which are glauconitic. 



The limestones in the section on Four-mile Creek were considerably 

 metamorphosed, and the fossils found, very indistinct. Still, those rec- 

 ognized identify the bed as belanging to the same horizon as the lime- 

 stones in the section made on Trout Creek, which is of Calciferous age. 



It may be that in the future the glauconitic beds will have to be de- 



