134 ENVIRONMENT OF VERTEBRATE LIFE, ETC. 



Stone and chert. This formation was not studied in detail, and no fossils were 

 obtained from it. It seems to correspond in position to the Quadrant quartzite. 



"The thick sandstone (No, 3) is overlain by a few hundred feet of gray 

 limestone, which is covered by sandy beds. Fossils obtained both from the 

 limestone and from the sandy beds are assigned by Mr. Girty to ' the Phosphoria 

 formation, now regarded as of Permian age.' 



"The gray limestone (No. 4) is overlain by 1,500 feet or more of thin-bedded 

 pinkish limestone, in which there may be some beds of shale. Fossils obtained 

 from the lower part of this limestone are provisionally referred by Mr. Girty to 

 the Lower Triassic." 



In the Garnet Range, a few miles east of Missoula, Montana, the 

 Quadrant formation is described by Pardee^ as — 



"300 feet or more of grayish-brown and yellow quartzite and red shale overlying 

 the Madison limestone in a narrow area extending from Tenmile Creek south- 

 eastward, also west of Little Bear Creek. * * * A little phosphatic sandstone 

 overlies the quartzite in the extreme southeastern part of the area surveyed, but 

 it dies out to the northwest. This phosphatic sandstone probably represents the 

 Phosphoria formation." 



Still farther to the northwest at Philipsburg, Montana, the Quadrant 

 preserves the character shown near Melrose. Of this locality Calkins and 

 Emmons^ say the Quadrant formation is divided into two members: 



Upper mainly quartzite. 



Impure quartzite and quartzitic sandstone. 



Calcareous shale and impure chert limestone. 



Light-colored quartzite, fine-grained, thick-bedded. 

 Lower red magnesian limestone and shale. 



Near Boulder Creek the beds are vertical and the quartzite forms promi- 

 nent reefs: 



The upper quartzite of the upper member is less fine-grained and is somewhat 

 calcareous. 



The middle bed is more calcareous and near Philipsburg is phosphatic. 



The lower quartzite is very fine-grained and thick-bedded. 



The fossils found in the calcareous beds between the quartzites are Cyathophylum ? 

 sp., Camarotcechia (or Rhynchopora) sp., resembling C. sappho, Camaro- 

 tcechia (or Rhynchopora) sp., resembling C. congregaia. 



Dr. Girty^ says of the fossils: 



"These fossils must be Pennsylvanian or Permian. The presence of phosphate 

 strata at this horizon suggests the Permian (?) phosphate beds of southeastern 

 Idaho (Phosphoria formation), but the fauna is different. Mr. Gale's suggested 

 correlation of the red lower members of the Quadrant with the Morgan formation 

 of northeastern Utah, as given below, is rather confirmed than otherwise." 



^ Pardee, J. T., Ore Deposits of the Northwestern Part of the Garnet Range, Montana, 



U. S. Geological Survey, Bull. 660, p. 167, 191 8. 

 ^ Calkins, F. C., and W. H. Emmons, U. S. Geological Survey, Philipsburg Folio, No. 196, 



p. 8, 1915. 

 ^ In Philipsburg Folio, p. 8. 



