[meteorite-list] Info on Caracas Peru impact event

[Robert Verish]

While out-of-town I got this message sent to me:

-------------- Forward Message --------------

Date: Fri, 21 Mar 2008 15:45:40 +0000
From: meteoreye at comcast.net

Subject: (Forward) Info on Caracas Peru Sept 17, 2007
impact event

The recent conference discussed what has been learned
so far about the  unusual impact event in Peru.
This info was provided by Jon Clarke, and Austalian
Geologist who keeps an eye on these things for me.
Note: quite a few interesting abstracts are linked.
Wayne

The just finished LPSC had a number of abstracts on
last years Carancas impact event.  Given the fact
there still seems to be some scepticism “out
there” regarding this event, here are some links
to the abstracts.  
The authors included researchers from Argentina,
Austria, Bolivia, Germany, Japan, Mexico, Peru, the
UK, Uruguay, and the US.
Harris et al. PRELIMINARY PETROLOGIC ANALYSIS OF
IMPACT DEFORMATION IN THE CARANCAS (PERU) CRATERING
EVENT.
 
http://www.lpi.usra.edu/meetings/lpsc2008/pdf/2446.pdf
 
Prado et al. 
THE METEORITE FALL IN CARANCAS, LAKE TITICACA REGION,
 SOUTHERN PERU: FIRST RESULTS.
 
http://www.lpi.usra.edu/meetings/lpsc2008/pdf/2555.pdf
 
Miura 
MULTIPLE EXPLOSIONS DURING CRATERING AT CARANCAS
METEORITE HIT IN PERU.  

http://www.lpi.usra.edu/meetings/lpsc2008/pdf/2027.pdf

Schultz et al. 
IMPLICATIONS OF THE CARANCAS METEORITE IMPACT.
 
http://www.lpi.usra.edu/meetings/lpsc2008/pdf/2409.pdf

Tancredi et al 
WHAT DO WE KNOW ABOUT THE
“CARANCAS-DESAGUADERO”
 FIREBALL, METEORITE AND IMPACT CRATER?


<http://www.lpi.usra.edu/meetings/lpsc2008/pdf/1216.pdf>
 
The impact was an ordinary chondrite, class H4 or H5,
traveling at 3-6 km/s. impacting at an angle of 45-60
degrees.  Initial velocities were 12-18 km/s, mostly
likely 16 km/s.   It is estimated to have had a 
diameter of 1.1 m, a mass of 3 tonnes, and the
explosion to have been equivalent to 2 tonnes TNT. No
fragment larger than a few kg was recovered.
  The meteoric material has weathered very rapidly. 
The impactor’s orbit was probably inclined at 25
degrees to the ecliptic and an aphelion inside the
orbit of Jupiter. 
The crater was 13.6 m in diameter and 1.04 m deep from
the ground surface to the submerged floor. Water has
risen to the ground level.  The rim is between 1 and 3
m high. There was a strong secondary steam explosion
from shallow groundwater heated by the impact.  The
crater was excavated into alluvium of a dry stream bed
and has a large ray, the rim has classic inverted
stratigraphy.  The crater walls have slumped 
significantly because of their wet unconsolidated
nature.  Numerous microscopic shock deformation
textures were observed in the ejecta.  
A paper has been submitted to the leading peer
reviewed journal Earth and Planetary Science Letters. 
I have access to this at work and will keep people
posted.
 Jon 

-------------- End of Forward Message ----------------