[meteorite-list] Marsden Canadian fall/first sedimentary meteorite??

[ensoramanda]

Hi All,

Looks like the Canadian meteorite might be the first sedimentary ever 
found eh!!!!  :-)

http://cgi.ebay.co.uk/My-pet-Rock-found-south-east-of-Lone-Rock-Saskatchewan_W0QQitemZ260324758120QQcmdZViewItemQQptZLH_DefaultDomain_2?hash=item260324758120&_trksid=p3286.c0.m14&_trkparms=72%3A1301%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

Graham Ensor UK

Rob Matson wrote:


>Hi All,

>

>One aspect of this new Canadian fall amuses me in particular. In

>the original report, we had quite a few "facts" about the bolide:

>

>  

>

>>SASKATOON - A fireball that lit up the skies of Alberta and

>>Saskatchewan last Thursday evening was a chunk of low-flying

>>asteroid that weighed about 10 tonnes before it struck Earth's

>>atmosphere, according to a University of Calgary investigation.

>>    

>>

>

>  

>

>>University of Calgary researcher Alan Hildebrand has outlined a

>>region in western Saskatchewan where he expects to find desk-sized

>>fragments of the space rock.

>>    

>>

>

>Of course, these first two paragraphs are quite inconsistent with

>each other -- a bolide that weighed only 10 tonnes *before* it hit

>the atmosphere would be the size of a SINGLE desk. That's prior to

>atmospheric ablation, which certainly would have reduced the mass

>by 70-90%. How do you find "desk-sized fragments" on the ground

>following ablation of a single desk-sized original object?

>

>  

>

>>The fireball pierced the atmosphere at a steep angle of about

>>60 degrees off the horizontal and lasted about five seconds.

>>    

>>

>

>The steep entry angle suggests catastrophic break-up into many

>pieces -- most of them small compared to the size of the original

>meteoroid. Obviously not desk-sized or even television-sized. Mind

>you, it's still an impressive fall. But I don't understand the

>need for hyperbole.

>

>How quickly people forget that we had an asteroid of KNOWN size

>(to within a factor of two) and orbit that entered over Sudan at

>a lower initial velocity and a much shallower angle, and yet

>"officials" poo-pooed that anything significant would reach the

>ground. This asteroid was at least 40 tons and quite possibly

>over 100 tons, had an orbit that intersected that of Mars

>(suggesting a possible SNC), and impacted in a location that

>would have been child's play to recover -- if it weren't for

>the minor matter of its landing in a third-world, genocidal

>disaster area of a country.

>

>I guess the point I'm trying to make is that the Sudan fall went

>off the radar almost immediately, yet was a far more substantial

>and scientifically important fall. But it seems not even meteorites

>are immune from sectionalism.  -Rob

>

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>