Presentation by Ian Kluft at California Meteorite Club in Escondido CA on September 14, 2014 about the theory of a newly-discovered impact structure at Nevada's Black Rock Desert. More info is at http://www.blackrocknevada.info/impact-crater/ .

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Presented by Ian Kluft
California Meteorite Club
Escondido, California
September 14, 2014

2. Black Rock Desert Impact Theory
● Black Rock Desert is in northwest Nevada
– 2 hour drive north of Reno
● This theory proposes an impact structure (eroded crater)
● Presentation order
– How the theory started
– Science of impact craters on Earth
– Current observations at Black Rock
– Upcoming research plans

3. Current research status
● Scientific method usually goes in this order
– Propose and test hypotheses
– Investigate theories
– Publish peer-reviewed papers
● This is currently a theory
● There isn't a peer reviewed paper... yet
– But that's the goal
● The evidence one way or the other exists in the rocks
– The data will tell the story

4. How the Black Rock Crater Theory started
● attempts at 1st amateur rocket to space 1998-2004
● exploring Black Rock Range in rocket search area 2002-2005
● bizarre rocks, "strangest volcano I've ever seen" 2002-2006
– I've seen large & small, old and young volcanoes at Mt Shasta area
– At Black Rock I didn't see volcanic structures: lava flows, cinder cones, etc
– Some rocks are the right color to look like lava
● impact crater theory 2007-present
● outline found in mountains 2009
● I had to learn about the science of impact crater recognition...

5. Science of Impact Craters
“Traces of Catastrophe” by Bevan M French
This book by a Smithsonian Institution geologist has become the
definitive resource on the science of impact craters.
You can download the PDF e-book at
http://www.lpi.usra.edu/publications/books/CB-954/CB-954.intro.html
Image: Lunar & Planetary Institute

6. Science of Impact Craters
Differences from traditional Geology
● "Cryptoexplosion structures"
– Until the 1960's, geologists didn't believe there were any impact craters on Earth
– “cryptoexplosion” was used for unexplained explosion structures
● Slow processes vs instantaneous
– Traditional geology wants all processes to be over millions of years
● Impacts are rare on Earth
– Unlike other rocky bodies in the solar system, Earth slowly erases its craters
● Enormously energetic
– Asteroids never make soft landings
– These are violent explosions that entirely destroy the impactor

7. Science of Impact Craters
Eugene Shoemaker (1928-1997)
● founder of impact geology
● studied structure of NV nuke test craters
● discovered Barringer Crater has same structure
● theorized Earth is covered in craters
– like the Moon
● studied/proved many impact craters
● co-discoverer of SL9 comet that impacted Jupiter in
1994
– made Earth aware of impact threat
Image: USGS via Wikipedia

8. Science of Impact Craters
Formation of impacts
● Crater about 10-20 times diameter of impactor
– Depends mostly on speed - minimum 25,000 mph
● hypervelocity impact destroys impactor
– mostly melted
● contact/compression stage
– extreme shock on rocks
● excavation stage
– explosion blows out crater

9. Science of Impact Craters
Formation of impacts (cont'd)
● modification stage
– debris falls down
– hot rocks cool down
● larger impacts, complex craters
– over 10km diameter on Earth
– terrace collapses on rim
– central uplift pushed up from sides
– uplift ring in largest craters
Image: NASA via Wikipedia

10. Science of Impact Craters
Decay Processes
● Earth slowly destroys its craters
● Erosion wears them away
● Faulting distorts them
● New layers bury them
● Plate tectonics slowly erases and renews the crust
● But the Moon still shows what firing line the Earth is in

11. Science of Impact Craters
How to Recognize Them
● from Traces of Catastrophe, Appendix 1
● occurs in any kind of bedrock
● generally single structures
● generally circular
● nearly any size: <1km to >100km
● relatively shallow, not a deep structure

12. Science of Impact Craters
How to Recognize Them (cont'd)
● anomalous feature within region
– unusual geology in circular area
– local deformation, faulting, breccias
– unusual breccias within structure
– possible central uplift peak or ring
– shatter cones
● one form of proof of impact
● conical shock fractures – even volcanoes can't make them

13. Science of Impact Craters
How to Recognize Them (cont'd)
● Look for geologic mysteries in literature
– intense, sudden, localized
– conventional explanations fail
– unusual “volcanic” explosions
● Measure geophysical attributes
– gravity
– magnetic
– seismic

14. Science of Impact Craters
How to Recognize Them (cont'd)
● rock types
– breccias
● Broken up and re-cemented rocks
● Always present in impacts, can be formed other ways too
– melt rocks
● Igneous rocks, but contents come from melting local target rocks
● microscopic shock effects
– Deformation, fracturing, melting
– Most proof of impact requires an electron microscope

15. Science of Impact Craters
How to Recognize Them (cont'd)
● Go explore confirmed impact sites
● I've visited...
– Barringer Crater (Meteor Crater) AZ
– Upheaval Dome, UT
– Sierra Madera Crater, TX
– Santa Fe Impact Structure, NM
– Middlesboro, KY
– Wells Creek & Flynn Creek, TN
– Odessa Crater, TX
● Share your pictures
– I've posted many on Wikipedia over the years

16. Current observations
● Observations started with rocks in 2007
– Trips to explore and observe at Black
Rock
– Online study: Nevada Bureau of Mines
and Geology
● Located at University of Nevada, Reno
● Scanned geological filings back to late
1800's
● Outline found in 2009
– Yes, it took 2 years!
– It's heavily eroded
Photo by Ian Kluft

17. Current observations
(cont'd)
● Breccia (broken/re-cemented rocks)
above fractured basement rocks
– We find this many places at Black
Rock Desert, miles and miles apart
– Impact theory suggests these are
rocks that got smashed, and rocks
that landed on them
– Best examples so far in Black Rock
Range
Photo by Ian Kluft

18. Current observations
(cont'd)
● Close spacing between joints in
basement rocks show intense
stress
– Credit to Bob Verish for making this
important observation
– Joints are larger cracks, like mini-faultlines
– After he pointed this out, we've found
basement rocks across miles with
narrow criss-crossing jointing Photo by Ian Kluft

19. Current observations
(cont'd)
● Testing the hypothesis:
These structures in the Black
Rock Range (and elsewhere
in the region) look like
volcanic necks.
● If they are, it would point
toward volcanic origin and
away from the impact theory.
Photo by Ian Kluft

20. Current observations
(cont'd)
● The supposed “volcanic
necks” are actually made of
breccia! They are gigantic
breccia dikes.
● This points toward an impact
origin and away from
volcanic.
● It suggests impact debris
that filled giant cracks.
Photo by Ian Kluft

21. Current observations
87km / 54 mile Ring in the Mountains
● 9 mountain ranges are either
arc-shaped or change elevation
significantly on the circle.
● Crutcher Canyon is concentric
outside the circle, apparent rim
terrace collapse
● Kamma Mountains are
concentric inside the circle,
apparent uplift ring
Terrain map by Google Maps, annotations by Ian Kluft

22. Current observations
87km / 54 mile Ring in the Mountains (cont'd)
● All the highest peaks of the Black Rock region are on the circle.
● All streams in the Black Rock watershed flow into the circle and
sink into the playa.
– The Quinn River Sink (lowest point) is at the center of the circle.
● Volcanoes do not make nice circles on this scale!
– Compare to Yellowstone Caldera: 55x72km / 34x45 miles
– The scale and quality of the circle point to an impact, not a volcano

23. Current observations
Why no shatter cones?
● Shatter cones are only proof of impact that don't require an
electron microscope
● At first I wanted to focus on looking for them
– It seemed easier
● Shatter cones occur in a very small percentage of the radius
– At Black Rock, there is apparently an uplift ring
– So the bedrock at the center is buried under the lakebed
● I realized this while visiting Middlesboro Crater in Kentucky

24. Geologic mysteries at Black Rock
Soldier Meadows Tuff
● A “tuff” is a volcanic ashfall
deposit
● 1980 MS thesis by Edmund
Stuart describes a mystery
● Soldier Meadows Tuff is a
single “cooling unit” - it all
came down in one sudden
event, over 200m thick.
● Where's such an enormous
volcano nearby?
Photo by Ian Kluft

25. Geologic mysteries at Black Rock
Soldier Meadows Tuff (cont'd)
● Impact theory suggestions about Soldier Meadows Tuff
– It is located just outside the 87km ring where ejecta is expected
– It would have landed in one sudden event, as observed
– It would be very thick just outside the rim, as observed
– Under the impact theory, it should be an impact ejecta layer
– For an impact this size, the ejecta layer should be very thick

26. Geologic mysteries at Black Rock
Sulphur Mining District
● 1980 geological summary
by geologist Andy Wallace
● Mystery of altered rocks
– And odd breccia dikes
Photo by Ian Kluft

27. Geologic mysteries at Black Rock
Sulphur Mining District (cont'd)
● “White breccia” rock layer feeds down into cracks
– Mystery how those were altered but not the rocks below
– Also increasing “volcanic” rocks as layers go up
● still old rocks from below too
● impacts do that – volcanoes don't
– Doesn't fit well with presumed hydrothermal alteration
– Fits well with alteration and melting from an impact
● Big fragments land first, followed by smaller rocks, increasing melt
● Suggests the “volcanic” rocks are actually impact melt

28. Upcoming research plans
● Find an electron microscope
– Not just any scope
– We need a lab with experience recognizing impact shock effects
● For example, shocked quartz
● Aerial video of mountains around rim
– Not proof itself, potential for interesting data collection
● Write a paper
– Co-authored with Bob Verish and others who contribute to the effort

29. Conclusions
● An 87km / 54mile impact structure at Black Rock, if confirmed,
would be the second largest in America.
– The largest is the 90km Chesapeake Bay Crater.
– You can't visit Chesapeake Bay crater because it's all buried.
● Most of Black Rock region is federal lands
– Anyone can go there.
– It's a tremendous opportunity for any researchers to study it.
– It could be a big resource for education about impacts.

30. Questions?
Thank you!