304 DESCRIPTIVE GEOLOGY. 



compact, fine-grained rock, in which, however, could be distinguished an 

 admixture of occasional quartz grains, were obtained: 



Silica 13.461 



Alumina ^ 1 fi27 

 Ferric oxide ) 



Manganous oxide 0.205 



• Lime 36.780 



Magnesia 8.438 



Carbonic acid 38.305 



Water and organic matter 2.045 



100.861 



Carbonate of lime * 65.678 



Carbonate of magnesia 17.719 



A specimen of soft deep-red sandstone from near the base of the series 

 gave the following: 



Silica 57.58 



Alumina ' 7.60 



Ferric oxide 0.67 



Carbonate of lime 27.28 



Carbonate of magnesia 2.04 



Soda 1.15 



Potassa 2.06 



Water 0.70 • 



99.08 

 No sulphuric acid was found, but the amounts of lime, magnesia, and 

 alkalies contained in this rock are very suggestive. • 



In the limestone bed between the two red sandstones was found a 

 Natica lelia, an identical form with that found at Rawlings Peak, though its 

 horizon is here more definitely known. This occurrence is interesting as 

 being the first fossil found in the Triassic beds east of the Wahsatch Mount- 

 ains. From the red sandstones to the bend of the canon, the continuity of 

 outcrops is somewhat obscured ; apparently mud-rocks and limestones pre- 



