CHARACTER OF THE OLDER TECTONICS 



551 



An uncomirLon type of ancient tectonics is displayed in the Humboldt 

 range. The general attitude of the strata is that of a low and simple 

 arch, the crest of which has been planed off, disclosing a central core of 

 Azoic crystallines. Modified from King, the structure is as represented 

 in figure 1. 



A more complex form of flexing is shown in the White Pine range. 

 The general surface of the district, which is evenly beveled, gives no sug- 

 gestion of an anticlinorium. There is, however, much detailed work 



Pogonip Mt. 



Mokeamoke Ridge 



Long Valley Range 



Figure 2. — Geologic Cross-section of the White Pine Range 



needed in this range before the real significance of its structure can be 

 made put. It is probable that in Spurr^s diagram (figure 2) certain 

 fault-lines are omitted. 



In the Funeral range there is the unusual phenomenon of soft Tertiary 

 beds constituting the main part of the mountains. These soft strata are 

 over 4,000 feet in thickness. They have been described as furnishing 

 critical evidence of very recent folding in all of the mountain ranges of 



Figure 3. — Apparent Folding of Tertiary Beds of the Funeral Range 



the Great Basin province. There appear to be in the Tertiary sequence 

 of strata an older section and a younger section, separated by a well 

 marked unconformity, which seems to indicate a true erosion interval. 

 The apparent fold in the beds is certainly due to the later layers resting 

 on the inclined surfaces of a ridge of the earlier sediments which are now 

 relatively hard sandstones. Opposite Mount Blanca the axis of the ap- 

 parent anticline is in the middle of the Furnace Creek valley, but 10 



