[meteorite-list] Re: Fr. Steve Arnold - The Brenham Story

From: Notkin <geoking_at_meteoritecentral.com>
Date: Fri Nov 18 01:36:30 2005
Message-ID: <0c12e90f7e079b814966c44b073c354a_at_notkin.net>

Darren posted:

> So, is this likely a seperate fall found in the same strewnfeild or a
> piece of Brenham? Are there
> other Brenham pieces that are all iron?


Hi Darren:

Good question. I believe there are several known pure Brenham irons
(i.e with absolutely no olivine). I'm sure Steve would answer himself
if he dropped that annoying AOL so he could post to the List : )

One iron was found quite close to the big pallasite. IMO they are
definitely from the same fall -- they were at similar depths, and show
comparable weathering. I discussed this with Steve at some length while
we were hunting.

I once saw a Brenham that had been prepared by Allan Lang. It was a
beautiful big slice that was about 95% iron with a little bit of
olivine right at the edge. So, it would seem that the original intact
Brenham mass might have incorporated a zone where an all-metal matrix
met a pallasitic area.

I wondered how it could be that you'd find an all-iron meteorite next
to an all-pallasite meteorite, and clever Steve pointed out that the
pallasitic masses are probably much more fragile. Therefore, is it
reasonable to assume that if/when the main mass exploded, in flight and
under atmospheric pressure, it might have split along the
iron/pallasite boundary -- thereby delivering to us some pallasites,
some irons, and maybe some mixed?

Anyway, you're right, it is kinda similar in that respect to Seymchan.

However you look at it, it's pretty cool to find an iron and a
pallasite in the same field!


Best,

Geoff N.
Received on Fri 18 Nov 2005 01:36:27 AM PST