542 E. BLACKWELDER GEOLOGY OF WASATCH MOUNTAINS, UTAH 



from an older and very thick series of qnartzite and slate which is pre- 

 sumably of Algonkian age. 



( h ) The exposed Algonkian series is probably not marine, but of conti- 

 nental origin, like the similar formations in Arizona and Montana. 



(c) The Ogden quartzite, as originally defined, has no existence, but 

 there is a thin quartzite of Ordovician age best exposed near Geneva. 



(d) The Silurian system has been identified in the main Wasatch 

 range by characteristic fossils, and the Devonian is doubtless present also. 



(e) In the Mississippian system there is an interesting series of sun- 

 cracked shales and peculiar limestones interpreted as a non-marine 

 deposit. 



(/) The Carboniferous red beds in Weber Canyon rest unconformably 

 on the Mississippian limestone and are themselves probably of terrestrial 

 origin. 



(g) The Weber quartzite thins north of the type locality and quickly 

 disappears. The fact is probably due to an unconformity between it and 

 the overlying Park City phosphatic series, both of Pennsylvanian age. 



(h) The current interpretation of the structure of the Wasatch range 

 must be modified to include large overthrusts with accompanying small 

 but intense folds and minor thrusts. 



(i) A transverse fault of large dimensions in the latitude of Ogden 

 has shifted the formations of the Wasatch and Bear Eiver ranges laterally 

 % to 3 miles. 



(;) The overthrusts are of Cretaceo-Eocene age, while the normal 

 faults are probably post-early Eocene. 



