[meteorite-list] Tektite looking objects found in Park Forest

From: Sterling K. Webb <kelly_at_meteoritecentral.com>
Date: Thu Apr 22 10:10:01 2004
Message-ID: <3E8BD5CC.B29F292D_at_bhil.com>

Wow!

    A great meteorite and now, tektites, too! Too much.
    Any rock melt that is quenched too rapidly to form crystals
will produce an amorphous liquid, otherwise known as a glass. In
the third picture (mixed forms), you will note on the left an
extended double droplet with a long "tail" that appears to be
sheared off very cleanly. This is very reminiscent of what you
would get if you snapped the tail off a cooled glass droplet. And
under this tailed droplet is what appears to be a long spike of a
tail that has lost its droplet! On the right is an elongated form
with both ends snapped off. In other words, not only do these
forms "look" like glass, they seem to have behaved mechanically
as a glass would.
    I would bet they are the last of the surface melt. The impact
comes after the body has gone subsonic. The airspeed is "only"
200 to 300 mph. The airflow that strips the melt from the stone
is much, much weaker now than at supersonic velocities and the
cooling of the airflow is at a maximum (hypersonic flow heats
instead of cools). The fusion crust has just solidified. These
last drops of melt may have solidified still attached to the back
of the stone and only snapped off at impact.
    "Dumbbells" are supposed to form from the rotation of an
oblate spheroid. They could be the last larger liquid drops to
leave the stone before impact with enough spin to distort before
cooling. In the third picture also note the large number of
"drops-with-a-tail," small spheroids with a weak bent tail
stretched out to a point. They look like drops that have just
pulled off the stone as they cooled, as if they were the last
drops to do so.
    If these little items are surface melt, they should show no
magnetic properties, as the melting would been at a temperature
above the Curie point where a prior magnetism vanishes. It is
quite possible that glassy droplets of melt accompany every
stoney meteorite and have just never been observed before. (If a
stone was found on a dirt patch, how many collectors would
analyze the dirt it rested on? Maybe we should start doing that.)
A comparison of the bulk composition of the droplets with the
bulk composition of the stone would be the obvious first test.
    It may be that the unique urban environment of this strewn
field (how many meteorites land IN A BOX?) and the thoroughness
of one collector has combined to reveal an entirely new kind of
meteoritic evidence.
    In a word, way to go!


Sterling K. Webb
-------------------------------------------------
Adam Hupe wrote:

> Dear List Members, You are going to think we are insane
> announcing this but we feel it is important. We acquired a
> computer game still in the box that was struck by a meteorite
> inside a house on Dunham street in the Park Forest
> neighborhood. This is from the same site that Mike Farmer
> purchased the House Hammering stone. This game box acted as a
> receptacle trapping some fragments from the meteorite, wood
> from the attic and sheet rock from the ceiling. While
> examining the contents of the game box under a microscope we
> were shocked to see the following objects: Dumbbell shaped
> glassy formsTeardrop shaped glassy formsRod shaped glassy
> formsPatty shaped glassy forms with sunken centersBall shaped
> glassy
> forms Dumbbellhttp://www.lunarrock.com/ParkForest/microtektites1.jpg Dumbbell
> and
> Teardrophttp://www.lunarrock.com/ParkForest/microtektites2.jpg Mixture
> of several
> types http://www.lunarrock.com/ParkForest/microtektites3.jpg These
> are all the same shapes you will find in Tektites, yet these
> cannot be called impactites since the meteorite did not melt
> any objects when it crashed through the roof. This is no joke
> so you collectors in the field may want to revisit the houses
> that were struck by meteorites and collect the debris left
> behind before it is too late. We do not know the scientific
> importance of this discovery but will find out soon since the
> University of Washington is interested in pursuing these
> strange objects. It has been suggested that these objects may
> have come from the ablation train left behind by this fall. It
> is our hope that more of this material is collected before it
> is too late. All the Best Adam Hupe
Received on Thu 03 Apr 2003 01:33:49 AM PST