Emery — Green River Desert Section, Utah. 555 



(fig. 2), and their correlation with beds in adjacent areas 

 is shown in the table on page 556. 



Pennsylvanian ( ? ) Sandstone. 



A sandstone of Pennsylvanian ( ?) age which is exposed 

 in Elaterite Basin and also outcrops rather broadly in 

 San Eafael Swell behind "The Beef," is the lowest 

 formation I had the opportunity of seeing in the Green 

 River Desert. It is heavily impregnated with oil on the 

 outcrop and is probably oil-bearing throughout its areal 

 extent in this region. 



This sandstone, which is composed mostly of translu- 

 cent quartz grains held together by calcareous cement, is 

 coarse-grained, massive, very cross-bedded, and rather 

 soft. Where not impregnated with petroleum it is white 

 both on the fresh face and on weathered surfaces, but 

 where filled with oil is a steel gray at the surface but dark 

 brown to black on fresh fracture. It commonly weathers 

 into deep pockets, constituting excellent rain water res- 

 ervoirs, and is further characterized in San Rafael Swell 

 by scarlet spots and blotches on the weathered surfaces. 



Near Temple Mountain, San Rafael Swell, fully 100 

 feet, and in Elaterite Basin about 50 feet of the Pennsyl- 

 vanian ( ?) sandstone are exposed. In both localities the 

 sand is heavily saturated with oil from top to bottom, but 

 the oil is definitely confined to certain, probably more 

 porous layers, for I saw no sign of oil in clean white 

 laminae in direct contact with dark petroliferous laminae. 



At the top of the Pennsylvanian (?) near Temple 

 Mountain is a very distinctive bed containing quartzite 

 pebbles and irregular areas of calcite and having the 

 appearance of a coarse, irregular conglomerate. It 

 attains a maximum thickness of 7 feet, but is locally 

 absent, which with its conglomeratic character is indica- 

 tive of an unconformity at this horizon. The presence of 

 an unconformity at the top of the Pennsylvanian ( ? ) is 



Legend (Fig. 2). 

 trlassic jurassic cret? cret. 



•Tb 



- "&c- 



K^ 





Shinarump Ch'm/e W/nyafe ss. Todilro Form. Navajo ss. M l £/mo Mancos shale 



con<}L form ' : — , ^~7i ' form and Pakora ss. 



La r/ara Group where present 



