[BR-Crater] Black Rock Range fault movement

[Scot Wilcoxon]

The Range fault is a normal fault, so the crust is extending there.  
Extending crust has been widely recognized in the region.  So the north 
end of the crater may be getting wider, rather than narrower.  If I'm 
reading the diagram correctly, the Range on the east side of the fault 
is displacing upward...and/or the west side of the fault is displacing 
the rock under the playa downward.  The previously mentioned study found 
recent movement of several meters, so there is no reason to assume the 
Range was at its present level after the impact.

The south tip of the Range is probably not an impact uplift, despite 
being near the center.  At least its present height is no clue to its 
characteristics after an impact.  However, the rock under the center of 
an impact could be interesting and the top of the Range may be easier to 
examine than what is under the playa.  It would be interesting if the 
top of the Range happens to have rock similar to that in the columnar 
joint bluff.