[meteorite-list] A short thesis on weathered NWA's and other thread killers

From: Dave Freeman mjwy <dfreeman_at_meteoritecentral.com>
Date: Sun, 18 Mar 2007 10:07:32 -0600
Message-ID: <45FD63C4.1010503_at_fascination.com>

Dear List;
I just received a hundred grams of some very weathered NWA's, at first I
was not even sure they were meteorites at all. Mild attraction to a
magnet but other than that, not a drop of crust, they looked like
crumbled red to tan clay bricks that should have been thrown out in the
driveway. I cut off a corner of each and sure enough, iron specks in
prime condition and quite hard on the interior.
Now, I recall seeing these deteoritated red bricks at a few indian
campsites in past years and the detector buzzing on them. At the time I
thought there was an iron factor caused by heating sandstone that had
some iron in it.
Back then, I was memorizing fusion crust in my brain....I suspect that
not all about meteorites is fusion crust, and as a cold hunter, that
maybe I have made way too much to do about fusion crust. Fresh fusion
crust is a wonderful thing but I am seriously thinking I may have done a
great injustice to my hunting efforts by not studying the most weathered
clinkers as those may be much more common than meteorites with good
crust, or even meteorites with ANY crust.
I was quite surprised and actually amazed to discover that really
weathered H-4-5's look so much like wasted brick.
I suspect that I have seen a number of severely weathered meteorites and
passed them up due to the fact that they weren't round at all, had no
crust, had no visible chondrules, and if not for a mild attraction to a
magnet, and the detector noting SOMETHING that I would have not even
remembered the where abouts or even the occurrence. I couldn't even call
these subjects rusty rocks even. Clinkers is a good word except for real
clinkers tend to be vesicular for the most part.
Thoughts?
Dave F.
Received on Sun 18 Mar 2007 12:07:32 PM PDT