[meteorite-list] Chelyabinsk - slickensides or shock planes?

From: Bob King <nightsky55_at_meteoritecentral.com>
Date: Tue, 21 May 2013 09:43:44 -0500
Message-ID: <CAG5KyVm_=SJ6rMobXkrSnDSwA_AQwDagwE9YJs-vKvtg24Ff4g_at_mail.gmail.com>

Hi Jim,
Thanks for your reply. No, what I'm seeing is different from the
secondary fusion crusts I typically see, and it's nearly identical on
many pieces. The broken faces have a planar, slickenside texture and
appear coated with gray material that's either fusion crust or as
Blaine thinks, an exposed shock plane.
Bob

On Tue, May 21, 2013 at 9:29 AM, Jim Wooddell <jimwooddell at gmail.com> wrote:
> Hi Bob and all!
> I might be wrong in assuming, but your slickensides sounds like you
> are attempting to describe secondary fusion???
>
> We have lots of evidence in various meteorites where they broke apart
> for whatever reason at the weak boundaries. For example, Franconia
> area meteorites (some) break apart from both sides of a metal vein
> leaving three pieces...two chondrite fragments and an H-Metal
> "cornflake".
> It's sort of like looking at a bad weld through xray.
> How can you tell? Look at more and look closer. A 3D CT sort of scan
> that has become popular with Sutter's Mill or Dr. Agee's research on
> "Black Beauty" may reveal what you speak of. Just my thoughts.
>
> Kind Regards,
>
> Jim
>
>
> On Tue, May 21, 2013 at 7:06 AM, Bob King <nightsky55 at gmail.com> wrote:
>> Hi everyone,
>> Many pieces of broken Chelyabinsk specimens display what appears like
>> fusion crust over slickensides, but is that what it really is? I've
>> talked with Blaine Reed and he thinks we're seeing blackish shock
>> veins (planes really) where the meteorite split along a line of
>> weakness. He even mentioned a piece he's seen where a large shock vein
>> in the matrix leads directly to the broken, dark face. Assuming
>> Chelyabinsk shows both slickensides and shock vein planes, how do you
>> tell them apart?
>> Thanks for your thoughts.
>> Bob
>> ______________________________________________
>>
>> Visit the Archives at http://www.meteorite-list-archives.com
>> Meteorite-list mailing list
>> Meteorite-list at meteoritecentral.com
>> http://six.pairlist.net/mailman/listinfo/meteorite-list
>
>
>
> --
> Jim Wooddell
> jimwooddell at gmail.com
> 928-247-2675
Received on Tue 21 May 2013 10:43:44 AM PDT