562 Emery — Green River Desert Section, Utah. 



and the massive Wingate sandstone. It is exposed in 

 The Ledge and upstream in the canyon of Green River to 

 within a few miles of the mouth of the San Rafael and 

 comes to the surface again back of San Eafael Reef. 

 Where the beds are inclined at low angles the Chinle 

 weathers back to a steep slope underlying the vertical 

 cliff: of the massive lower portion of the La Plata group, 

 but where not capped by La Plata weathers into badland 

 forms. 



Shale predominates in the lower part of the Chinle 

 formation but gives way to sandstone above. The shale 

 is very argillaceous, rather firmly cemented, hard, friable, 

 and of variegated colors, including heliotrope, lavender, 

 mauve, turquoise, dove, cream, and white, and with it are 

 interbedded thin sandstones similar to those constituting 

 the upper part of the formation. The shale rather grad- 

 ually loses its "marl "-like character becoming more and 

 more sandy until finally in the upper part of the forma- 

 tion the beds are sandstone rather than shale. This 

 sandstone is fine-grained, massive, cross-bedded, and in 

 the San Rafael Swell region its color is maroon with a 

 terra-cotta cast, but under The Ledge the color partakes 

 more of an orange-terra-cotta, the maroon tinge being 

 absent. 



In the section measured in Elaterite Basin a limestone 

 conglomerate such as occurs in this formation in the Nav- 

 ajo country, where it is a diagnostic feature, is present 

 in the Chinle about 35 feet above its base. Near Temple 

 Mountain, however, the Chinle consists entirely of sand- 

 stone and shale, but limestone conglomerate like that 

 which elsewhere occurs in the body of the formation is 

 present at the base. 



A detailed section of the Chinle was not measured in 

 Temple Wash, near Temple Mountain, San Rafael Swell, 

 but its thickness was determined as 210 feet. In this 

 locality approximately the lower one-half of the section 

 is composed of variegated, heliotrope, lavender, mauve, 

 and red-brown argillaceous shale containing thin beds 

 of sandstone, while the upper part is composed princi- 

 pally of sandstone which is medium-grained, much cross- 

 bedded, lenticular and terra-cotta maroon in color. A 

 detailed section of the Chinle rocks measured along the 

 trail over The Ledge between French Spring and Elater- 

 ite Spring follows : 



