62 



STRUCTURAL GEOLOGY OF NORTH AMERICA 



SOUTHEASTERN 

 IDAHO 



WIND RIVER 

 MTNS. 



DEVONIAN 



NORTHERN 

 BLACK HILLS 



I 

 WHITEWOOD DOLry 

 GREEN SHALE ft L 

 SCOLITHUS SS-7/ 



Stratigraphic diagram showing the relations of Cambrian and Ordo- 

 vician rocks between southeastern Idaho and the northern Black Hills. 



Fig. 5.24. Relation of shelf in Wyoming to Transcontinental Arch and Cordilleran geosyncline. Repro- 

 duced from Thomas, 1949. 



on the sites of deposition is shown on Plate 7, and Fig. 6.7. Figure 5.24 

 is a cross section to illustrate the shelf and its relation to the Trans- 

 continental Arch and the Cordilleran geosyncline. 

 The formations of the Wyoming and Montana part of the Utah- 



Wyoming shelf differ somewhat from those of the Utah and Arizona 

 part. The formations have been the object of numerous stratigraphic 

 studies because of their importance as oil and gas producers. See cor- 

 relation charts listed in Chapter 1. 



