[meteorite-list] Larry's Holbrook Holy Grail Find

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Tue, 13 Feb 2007 00:46:15 -0600
Message-ID: <148201c74f3a$a8dfb880$d9342b41_at_ATARIENGINE>

Hi, Everybody

> Nothing that says the larger ones are found in the
> furthest part of the strewnfield.

    Actually, Norton's "Rocks From Space" (2nd Edition,
pp. 70-72) says just that: "The more massive meteoroids,
with their greater kinetic energy... travel further down the
major axis of the distribution ellipse before impacting
Earth."
    He shows a map of the Homestead, Iowa strewnfield
showing its distribution by weight, and for a recent site.
He does say that with larger fields or ones with more
numerous small fragments, this distribution may be
"concealed" or hard to map.
    Of course, Holbrook is a classic fall of "many small
fragments," but presumably IF you had a map that
charted the find location of EVERY piece by weight,
some such pattern would appear.
    C of M says, "a shower of stones fell, estimated to
number 14,000, of total weight about 481lb (218kg),
with individuals weighing from 6.6kg to a few milligrams."
    Where'd that 14-pounder (6696 gm) fall? Anybody know?
    Here's a paper on the distribution of sizes (not locations):
http://www.iop.org/EJ/article/0295-5075/43/5/598/node4.html
They say Holbrook is the product of two breakups, one
after the other, when the largest fragment then re-fragmented
again.
    I just posted a nice eyewitness account of the Holbrook
fall that I ran across. I note particularly the remark in that
account that says all the larger pieces were embedded six
inches or more in the soil and all the smaller pieces were
found on the surface of the ground.
    Perhaps the really BIG Holbrooks are still down there?


Sterling K. Webb
---------------------------------------------------------------------
----- Original Message -----
From: "DNAndrews" <dna1 at cableone.net>
To: <meteorite-list at meteoritecentral.com>
Sent: Monday, February 12, 2007 10:53 PM
Subject: [meteorite-list] Larry's Holbrook Holy Grail Find


Hola Johnny Q,
You may be right, but as large as that piece was, it might have taken a
couple of years or so for it to be washed or eroded out. But you are
right, it was found near the top of a mound....just slightly down from
the top. Even one fragment was found under a cow pie. ;-)

The miniscule 69 gms. I found that day (largest fragment 43 gms...one of
my better days), just didn't seem worth fussing over after Larry's
whopper "Holy Grail" find. ;-)

I hope we can post some pictures with some meaning and size scale to
it. I have some. The pictures Mark posted (thanks Mark) have no
indication as to size. Also, I think that "minus" the fragment
weights, should be worded "plus" the fragment weights. I know that
piece is at least a kilo in weight. Maybe the largest Holbrook in 30
yrs. or so? Maybe Steve Schoner could refresh our memory on his/or
others finds? I know he has found some large ones in the past.

As far as Bernd's question as to the distribution of large to small
stones, I see no pattern whatsoever. Seems to my personal experience,
the larger ones are in the middle of the north side. However, there are
records of 5 lbs. found on the south side in 1969. (Everet Gibson, I
believe). I/we've found a lot of stuff on the south side, but as to
when I was there, nothing of size larger than 20 gms....then came Maria
last year. She found 100g or so of an individual in the eastern past on
the south side. Nothing that says the larger ones are found in the
furthest part of the strewnfield.

I've been working on finding things further from the horizontal and
vertical plane of the field. I feel in the last few years that we have
expanded the 2 mile x 1/2 mile rule by quite a bit. I'm only sharing
this info because it really isn't easy to just walk in here and find
something substantial. Well....I take that back...Larry just did it.

Congrats to Larry....don't know how you did it, but you did it.

Dave
(Sending this as plain text in hopes it will be posted)
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Received on Tue 13 Feb 2007 01:46:15 AM PST