HAVALLAH EANGE. 679 



noteworthy that no Carboniferous rocks have been recognized west of the 

 Battle Mountains and no Mesozoic ones east of the Havallah Range. 



The granite body stretching out to the northeast on the west side of 

 Ragan's Valley is overlaid about 3 or 4 miles south of the Humboldt River 

 by a series of limestones and intercalated calcareous and argillaceous shales 

 and slates. The strike of these rocks is about north 30° east, and their 

 general structure that o^ a synclinal, through whose axis there has broken 

 out a mass of propylite. Microscopically, this propylite contains a little 

 quartz, and has been classed by Professor Zirkel as a quartz-propylite, but 

 the quartz seems to be a purely accidental ingredient, or else occurring in 

 segregations, and is not generally diffused through the mass. 'A remarkable 

 feature of the rock is the presence of liquid-inclusions in the quartz-grains. 

 The rock closely resembles in habit and texture the hornblende-propylite 

 of Washoe, and has therefore been colored as a propylite on the geolog- 

 ical maps. 



An analysis of this rock was made by Dr. Walter Kormann in the lab- 

 oratory of the University of Leipzig, with the following result: 



Silica '- 6G.336 



. Alumina 14803 



Ferric oxide '- 4.068 ■ 



Lime 2.991 



Magnesia 0.920 



Soda 5.1G0 



Potassa 3.190 



Carbonic acid 1.034 



Water 2.307 



100.809 



It will be seen, by comparing this analysis with the well-known pro- 

 pylite from Washoe, that it stands at least 6 per cent, higher in silica, but 

 is at the same time several per cent, lower than the normal quartz-propy- 

 lites of the Virginia Range. The amount of carbonic acid and water 

 present would indica,te that the rock has undergone considerable decom- 

 position. . 



