[BR-Crater] Black Rock Range fault

[Scot Wilcoxon]

In the Slashdot discussion, someone pointed out the Black Rock Range was 
a linear feature rather than the central uplift which happens in some 
craters.  I responded that there has been a lot of erosion, and the 
desert floor is not the crater floor.  The crater floor may have been 
hundreds of feet higher (I think one jointed column bluff is 200 feet?).

So one issue is whether the top of the Black Rock Range is no higher 
than the crater floor.  If so, then the Range could have formed by 
erosion of its surroundings.  And crater floor formations might be on top.

Another possibility is that the Black Rock Range is due to an uplift 
which is separate from the force which created the crater.  Such as 
tectonic compression of the area causing a weakness along the Range to 
fold upward.

"Isostatic rebound, active faulting, and potential geomorphic effects in 
the Lake Lahontan basin, Nevada and California", Figure 3, page 1742
http://neotectonics.seismo.unr.edu/CNS_pdfs/Adams99isostatic.pdf

There is a fault line along the Black Rock Range.

Another thing to investigate is whether there has been enough 
compression to change a circular crater to the current elliptical shape.