[BR-Crater] how the new outline affects studying the crater

[Ian Kluft]

Here's what I'm thinking about changes we can make to plans for studying
the suspected impact crater based on the new crater outline estimate.
If you have thoughts on it, toss them into the discussion.

This has taken my (maybe our, you can decide for yourself) blinders off
about the old elliptical outline theory.  That was, in hindsight, mistakenly
following the line of the Calico Mountains which were too straight and should
have been rejected.  Next to the perfect circle of the new outline, the
Calicos now stand out as a straight line probably caused by post-impact fault
uplift.  But I can see how I fell for it - the ellipse pattern is still far
more easily visible on a relief map than the perfect circle.  On a 50-mile
scale, details even at the size of mountains become too small to easily see
how they fit together.

The new estimate has moved the center of the crater south-southwest about
4 miles.  It changes the area of central uplift to a larger ring.  Basically
the area previously dubbed the "Southern Rings" are part of the central ring,
not the rim of the crater.  Much more central uplift area remains to be
searched than we previously thought.  Any central uplift area is where I
think we should look for shatter cones.

The center point (40.900 N 118.920 W) is still on the playa, but now near
the Quinn River Sink.  So we still have the same problem - there's no
bedrock to examine at the center point.  But I think we have a lot more
reason for confidence in the estimated center now that we have a perfect
circle outline.

In the Black Rock Range, we should focus more on the very southern tip, 
instead of southeastern.  We weren't far off.  (Obviously, because we found
what are probably poorly-formed shatter cones in 2 locations.) This may help
us direct the search better and make better use of limited travel time.  The
southern tip gets us 2 miles closer to the center than both the places that
the probable poorly-formed shatter cones were found.  That's very encouraging!

Pahsupp Mountain (40.777 N 118.993 W) next to Jungo Rd/Old Hwy 49 is the 
next closest place to the center point, but south of it.  So it should be 
almost as good a location to search as the southern Black Rock Range.  It 
may have its own advantage because the line of the mountain range looks
like it may have had fault uplift, which could expose buried shatter cones.
And it doesn't require waiting for the playa to dry out to get there.  So
that should be the next destination.

Since Jungo Rd is a dirt road, I'd like 2 weeks of dry weather before we go 
there.  For now the weather is in a wet pattern at least until early next 
week.  So a trip could not be any sooner than Feb 7-8.  If others think this 
makes sense, then it could be the beginning of a plan for Crater Assault 4.