[meteorite-list] Czech meteorite fragments 20 years

From: Mark Bowling <minador_at_meteoritecentral.com>
Date: Thu, 16 Oct 2014 06:22:45 -0700
Message-ID: <1413465765.20157.YahooMailNeo_at_web160402.mail.bf1.yahoo.com>

Just to play Devil's advocate, is this desert varnish, or some kind of reaction to a humid, heavily mineralized soil? Have they been shared with other institutions? It's implied that they were found buried in the ground. Perhaps they did find them, and it's some sort of alteration caused by local ard/gossan conditions.

Any geos on there who might know of a mechanism that could cause a similar looking weathering product? These are just photos, which, more often than not, are very hard to interpret. I'm partly curious as I've observed some interesting rocks while prospecting high sulfide locations.

Assuming they were genuinely found, in such conditions it may be possible they are 20 years old. Or they could be much older, and it's just chance that they found some very old, highly-weathered meteorites unrelated to their "impact location". In such a case, is there a dating method that could determine their true terrestrial age?

Yes Holbrooks are pretty fresh, but they are in a semi-arid location, in sand dunes which probably wick away moisture. Stones found in the dunes are very fresh, while some in the flats are a lot more rusty.

Anne brings up a good point that diverse types can be found from one event. I'm not saying that she agrees - odds are they are planted. But I just want to keep an open mind and keep asking questions.

Another possibility is that one or two team members planted them and kept other members in the dark. They may have documented removal of the last couple found, thus adding more "evidence" that they are legit. But while they selected similar looking stones, they actually were different types (?).

Anybody know some of these team members and if they are qualified to do this sort of work/have good reputations? Is this peer reviewed?

Odds are they are kooks or cheats. But maybe they are on the up and up, but simply have foolishly linked these "finds" to a relatively recent fall(???).

It will be interesting to see what develops!

Mark Bowling





________________________________
From: Michael Farmer via Meteorite-list <meteorite-list at meteoritecentral.com>
To: Paul Gessler <cetuspa at shaw.ca>
Cc: meteorite-list <meteorite-list at meteoritecentral.com>; MEM <mstreman53 at yahoo.com>
Sent: Wednesday, October 15, 2014 5:13 PM
Subject: Re: [meteorite-list] Czech meteorite fragments 20 years


Not to mention they are highly desert varnished, something never seen in a wet place, and different types.
Whoever pulled this scam is pretty foolish.
Michael Farmer

Michael Farmer

> On Oct 15, 2014, at 5:02 PM, Paul Gessler via Meteorite-list <meteorite-list at meteoritecentral.com> wrote:
>
> Looks like something that was found sitting in a Moroccan sale bin for the last 20 years.
> They look a lot older than 20 years to me.
>
> Paul G
>
>
> -----Original Message----- From: MEM via Meteorite-list
> Sent: Wednesday, October 15, 2014 4:53 PM
> To: Meteorite Mailing List
> Subject: [meteorite-list] Fw: [Geology2] Meteorite fragments discovered 20years after bolide event in Czech Republic
>
>
> <www.sciencedaily.com/releases/2014/10/141014142736.htm>
>
> Meteorite fragments discovered 20 years after bolide event in Czech Republic
> Date: October 14, 2014
> Source: Astronomy & Astrophysics
> Summary: Scientists have discovered meteorite fragments 20 years after the corresponding bolide
> was seen in the skies of the Czech Republic. This discovery was made possible by reanalyzing the trajectory, which moved the impact line by 330 meters. Interestingly, the meteorites found on the ground are of
> different types, pointing to a parent asteroid of heterogeneous composition.
>
>
>
> ________________________________
>
>
> First three Bene?ov meteorites found in April 2011, with metal detectors. From left to
> right: H5 chondrite of 1.56 g, LL3.5 chondrite of 7.72 g with achondrite clast, and LL3.5 chondrite of 1.99 g [2].
> Credit: Image courtesy of Astronomy & Astrophysics
>
>
> Astronomy & Astrophysics is publishing the spectacular discovery of meteorite fragments 20 years after the corresponding bolide was seen in the skies of the Czech
> Republic. This discovery was made possible by reanalyzing the
> trajectory, which moved the impact line by 330 meters. Interestingly,
> the meteorites found on the ground are of different types, pointing to a parent asteroid of heterogeneous composition.
> Collisions of meter-sized meteoroids with Earth's atmosphere are
> relatively rare, occurring about 40 times a year. They cause very
> spectacular events, known as superbolides. One of the best known such
> events, the Bene?ov bolide, occurred on 7 May 1991 at 23h 03m 46s UT
> over the Czech Republic. It was recorded during systematic photographic
> observations by the European Fireball Network and certainly ended in a
> multiple meteorite fall, but no meteorite was found in the weeks and
> years after the fall, despite many attempts.
> In February 2011, nearly 20 years after the event, P. Spurn? and his
> colleagues [1] measured the records again and analyzed the data with
> improved methods. This led to a new picture of the whole event with a
> revised atmospheric trajectory and a new impact location. This allowed
> the team to recover the Bene?ov meteorites, 20 years after the fall,
> exactly in the newly predicted area. It is the first time a meteorite is found so long after the bolide observation.
> The team found four small, highly-weathered meteorites with a total
> mass of 12 g. The probability that these four fragments come from
> different meteoroids and were found by chance at the same place is
> estimated to be 1 in 100,000 or less. Even more interestingly, these
> four meteorites are of three different mineralogical types. This means
> that the Bene?ov meteoroid was heterogeneous and contained at least
> three different types of material. After the Almahata Sitta fall, this
> is the second time that such a heterogeneous composition has been found. It raises the possibility that a significant fraction of all asteroids
> are heterogeneous and that they were strongly reprocessed by collisions
> with other asteroids in the main belt.
> ________________________________
>
> Story Source:
> The above story is based on materials provided by Astronomy & Astrophysics. Note: Materials may be edited for content and length.
> ________________________________
>
> Journal Reference:
> 1. Pavel Spurn?, Jakub Haloda, Ji?? Borovi?ka, Luk?? Shrben?, Patricie Halodov?. Reanalysis of the Bene?ov bolide and recovery of polymict breccia meteorites ? old mystery solved after 20 years. Astronomy & Astrophysics, 2014; 570: A39 DOI: 10.1051/0004-6361/201424308
> ________________________________
>
>
> Astronomy & Astrophysics. "Meteorite fragments discovered 20 years after
> bolide event in Czech Republic." ScienceDaily. ScienceDaily, 14 October
> 2014. <www.sciencedaily.com/releases/2014/10/141014142736.htm>.
>
>
>
> .
>
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Received on Thu 16 Oct 2014 09:22:45 AM PDT