HINTZE, GEOLOGY OF WA8ATCH MOUNTAINS, UTAH 93 



and Parley^s Park, the most extended and instructive stratigraphic ex- 

 hibition of the Paleozoic series in the Fortieth Parallel area." ° 



It now appears that the Ogden area, recently visited by Blackwelder^ 

 and some of his colleagues from the University of Wisconsin, and the 

 Cottonwood Canyon district, covered by the writer last summer, are simi- 

 larly characterized by complicated structures involving large overthrusts 

 which duplicate the rocks of the lower members of the Paleozoic series 

 and give an apparent thickness which is much too great. Blackwelder 

 has shown that the Ogden quartzite of Hague and Emmons does not exist 

 as originally defined. Elsewhere in this report, it is shown that the Ute 



N E /-vjff^^J^*^ ^T^ .^f¥mrXJ^/mm//yMi''^^ s w 



^ms fp Pw<j' M D O € 



FIG. 2. SECTION EXPOSED BETWEEN THE MOUTH OF BIG COTTONWOOD AND THE HEAD OF 



MILL CREEK CANYONS 



AI = Algonkian. C = Cambrian. O = Ordovician. D = Devonian. M ^ Mississip- 

 pian. Pwq = Penn. Weber quartzite. Pp ^=. Penn. Park City formation. Pws := Per- 

 mian Woodside shale. Tt = Triassic Thaynes formation. Ta = Triassic Ankareti shale. 

 Jn = Jurassic Nugget sandstone. 



limestone of supposed Silurian age also has no existence as such in the 

 central Wasatch, but is in reality the lower part of the Wasatch limestone 

 reported as belonging to the Carboniferous. It seems strange that this 

 relation should not have been discovered by the early workers on account 

 of the marked contrast between the sequence of beds near Alta in Little 

 Cottonwood Canyon and that seen across the divide to the north in Big 

 Cottonwood Canyon. 



BIG COTTONWOOD SECTION 



At the mouth of Big Cottonwood Canyon is exposed the base of the 

 great section of Paleozoic and Mesozoic rocks above referred to by King. 

 Beginning on the strike of the beds which stand at a high inclination 



5 C. King : U. S. Geol. Expl. 40th Par., Sys. Geol., Vol. I, p. 165. 1878. 

 « E. Blackwelder : "New Light on the Geology of the Wasatch Mountains, Utah," 

 Bull. G. S. A., Vol. 21, pp. 517-542. 1910. 



