[meteorite-list] Fossil Meteorites Arrive at The Field Museum

From: Shawn Alan <shawnalan_at_meteoritecentral.com>
Date: Sat, 28 Jun 2014 16:51:54 -0700
Message-ID: <20140628165153.e8713c95af9984a493c5db01816d4c10.3a3aa27d43.wbe_at_email22.secureserver.net>

Hello Listers

Now I need to get one of these fossilized meteorites in my collection :)

Enjoy the article.

Shawn Alan
IMCA 1633
ebay store http://www.ebay.com/sch/imca1633nyc/m.html
Website http://meteoritefalls.com

Fossil Meteorites Arrive at The Field Museum
source:http://www.fieldmuseum.org/explore/science-newsflash/fossil-meteorites-arrive-field-museum

They are the ?Mona Lisas? of meteorites ? out of over 50,000 known
meteorites, only 101 of them are fossilized, and four of them will be on
display at The Field Museum.

These meteorites have a fascinating story! Back in 1952, the manager of
a limestone quarry in Sweden that was once an ancient sea floor noticed
an unusually dark object in a slab that one of his workers had cut and
set aside. He approached a paleontologist about it, who set it on a
shelf in his office and forgot about it. 27 years later, a mineralogist
who was interested in meteorites walked into that very same office, and
exclaimed, ?That looks like a meteorite!?

The discovery of this meteorite nearly three decades after it was
removed from the quarry led to a systematic search for more?in fact,
workers were trained to recognize them. Over the next 20 years, 101
fossilized meteorites were uncovered in the quarry, which is 100 times
more than we would expect. Philipp Heck, Robert A. Pritzker Associate
Curator of Meteoritics and Polar Studies at The Field Museum, tells us
why.

?These meteorites all came from the same source,? said Heck. ?The
breakup occurred somewhere between Jupiter and Mars ? nowhere near
Earth. We know that because the collision generated fragments ranging
from millimeters to feet in diameter that have been found in Russia,
China and Sweden, indicating that this was a global event. In fact, I
would venture to guess that fragments of this meteorite can even be
found on Mars.?

Like all fossils, the 101 meteorites that have been recovered in the
quarry became fossilized when the original material was replaced by
other minerals during the transformation of the soft seabed to
sedimentary rock. However, these meteorites contain a mineral called
chromite that was preserved in its pristine form that matches the
composition of L chondrites ? the second most abundant type of
meteorites that fall to Earth today.

?There is one exception,? said Heck. ?Out of the 101 fossilized
meteorites, one of them did not match the composition of the L
chondrites. We do know that it took the same amount of time to reach
Earth as the others, so we think it may be part of the projectile that
caused the parent asteroid to break up.?
Received on Sat 28 Jun 2014 07:51:54 PM PDT