HINTZE, GEOLOGY OF WASATCH MOUNTAINS, UTAH 87 



led to a new conception of the stratigraphy as well as the structure of 

 this part of the range. The finding of many new fossil species has shed 

 important light on the age of the paleozoic rocks, and the discovery of 

 several disconformities has enabled the writer to subdivide the series into 

 several new formations. Observations on the physiographic features of 

 the central Wasatch have afforded interesting results on the present state 

 of dissection of the Wasatch block mountain and have suggested an ex- 

 planation of the principal drainage lines of the region. Other problems 

 are partly solved, and much work will still have to be done before a com- 

 plete account of the many interesting geological phenomena here shown 

 can be given. 



The writer desires to thank the mining men of South Fork and Alta 

 most heartily for the support and assistance which they generously ex- 

 tended to him during his field work. While it does not seem possible to 

 mention the names of all who have rendered help, the writer cannot for- 

 bear to acknowledge the cordial treatment shown him by Mr. Green of 

 the Tar Baby Mining Company and Mr. Barney of the Cardiff Mining 

 Company in South Fork, and at Alta by Mr. Blake of the Columbus 

 Consolidated, Mr. Lemmon of the Columbus Extension, Mr. Jacobson of 

 the Alta Consolidated, Mr. Godbe and Mr. Burton of the Michigan Utah, 

 Mr. Gabrielson of the South Hecla and Mr. Stillwell of the Emma. To 

 the managers and directors of these mines, the writer is grateful for the 

 privilege of visiting the various properties and studying the ore deposits. 



To the several members of the Department of Geolog}^ at Columbia, 

 the writer feels greatly indebted for many helpful suggestions in the 

 preparation of the report. To Professor Amadous W. Grabau is due 

 special thanks for the encouragement he has given from the very outset. 

 Throughout the laboratory work, and especially on the paleontologic and 

 stratigraphic side, he has manifested great interest in the results as they 

 appeared. His kindly criticism has been of much value and assistance 

 in formulating the conclusions here drawn. To Professors D. W. John- 

 son and C. P. Berkey, the writer is indebted for many valuable criticisms 

 relative to the physiographic and petrographic features of the work. 



Physiogeaphy 



oeigin of the wasatch mountains 



Immediately following Cretaceous time, the present Great Basin prov- 

 ince was the scene of dynamic disturbances through which numerous 

 mountain ranges were formed by the processes of folding and overthrust- 

 ing. During early Tertiary time, the folds were truncated by erosion 



