BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 VOL. 11, PP. 377-388, PL. 23 MAY 31, 1900 



JURASSIC ROCKS OF SOUTHEASTERN WYOMING 



BY WILBUR C. KNIGHT 



(Presented before the Society December 29, 1899) 

 CONTENTS 



Page 



Introduction 377 



Early investigators 378 



Mountain ranges, folds, and faults 379 



Distribution of Jurassic rocks 380 



Sioux Fault section 381 



Freezeout Hills section 381 



Red Mountain section 382 



Correlation of the sections 382 



Grouping of the Jurassic 383 



Its divisions 383 



Como stage and its fossils ... 383 



Extent of Como stage .... 385 



Shirley stage and its fossils 385 



Extent of Shirley stage ." 386 



The Jura and Jura-Trias 387 



Suggestions as to correlation 387 



Introduction 



In Wyoming, as in many of the Rocky Mountain states, there has 

 been but very little detailed geological work done, and our present ver} r 

 limited knowledge is largely based on the reports of the early reconnais- 

 sance surveys. Large areas remain unknown to science that have not 

 been mapped or approximately described. These are more common 

 than is generally supposed, and often contain several hundred square 

 miles. One of these areas extends from the Union Pacific railroad, in 

 Carbon county, north to the Laramie mountains, and from the North 

 Platte river eastward more than 50 miles, and includes the great dinosaur 

 fields that have recently attracted considerable attention, and also con- 

 stitutes an important portion of the territory to be considered in this 

 paper. 



LIV— Bui.t,. GF.or,. Soc. Am., Vor,. 11, 1899 (377) 



