CARBONIFEROUS UNDIVIDED. 379 



Girty states that the " Permo-Carboniferous " of the foregoing section is equiva- 

 lent to Walcott's Permian, not to the Aubrey group of the Grand Canyon section. 



Blackwelder "^ states that the Weber Canyon section as described by King is 

 subject to corrections brought out by more recent study. Near the base of the 

 section there are faults which complicate the succession. The quartzite, supposed 

 to be the Ogden quartzite of King (Devonian), is in reality the Middle Cambrian 

 (Brigham quartzite) and the olive-colored argillites are Middle Cambrian shale. 

 The nonfossiliferous lower portion of the Carboniferous limestone may well include 

 beds of Devonian age such as have been found on the borders of Cache Valley farther 

 north. The fossils in the "Wasatch limestone" are typical members of the wide- 

 spread Madison fauna, which is of early Mississippian age. Upon the weathered 

 and slightly irregular surface of the limestone rests the Morgan formation of Weeks,^** 

 consisting of brick-red shale and sandstone with a few beds of gray limestone and 

 light-colored sandstones which become bright red on exposure. This passes up con- 

 formably into the lower, more or less calcareous portion of the Weber quartzite. 

 The quartzite itself has not been remeasured accurately, but the thickness reported 

 by King is believed to be somewhat excessive. The alternating series of dark lime- 

 stone and shale with local sandstone beds, which rests upon the Weber quartzite, 

 corresponds to Boutwell's Park City formation. It contains the workable phosphate 

 deposits of the region. There is considerable although not conclusive evidence of 

 an important unconformity between the Weber and Park City formations. A sec- 

 tion measured in undisturbed strata near the headwaters of Ogden River is given 

 below for comparison with the Weber Canyon section : 



Partial columnar section of Carboniferous heds in the northeastern part of Weher County, Utah. 



rennsylvanian: Feet. 



Park City formation (upper portion concealed or removed by erosion) : 



Dark shale with beds of limestone and rock phosphate 438 



Gray limestone with chert nodules and beds of shale 301 



Creamy- white sandstone with beds of cherty limestone 220 



Unconformity? 



Mississippian (perhaps including early Pennsylvanian at the top): 

 "Wasatch limestone:" 



Gray crystalline limestone and purplish shale containing nodules of bright-green lime- 

 stone (abundant fossils — Productus, Spirifer, etc. — ^tentatively referred by G. H. 



Girty to the Kaskaskia formation of the Mississippi Valley) 140+ 



Dark-gray limestone and dolomite with beds of calcareous sandstone. Fossils rare or 



poorly preserved 795 



Black phosphatic shale and cherty limestone 126 



Limestone, black to gray, with chert nodules only near the top. Abundant fossils, 



especially in the lower layers, the species being typical of the Madison fauna 1,015 



Gray shale and limestone with poorly preserved marine fossils like those just above. 180 

 Shale, dolomitic limestone, and sandstone; ripple marks and sun cracks and bright 



ferruginous bands suggest nonmarine origin. No fossils 220 



Obscure unconformity. 



Hard siliceous limestone and dolomite, largely concealed. No fossils found in these 

 rocks, but the lower layers may be equivalent to the Devonian limestone of the 

 Bear River Mountains 1,100-f- 



4,535-1- 

 o Personal communication. 



