[meteorite-list] Weathering Grade and Shock Stage

From: Bernd Pauli HD <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 10:08:20 2004
Message-ID: <3D73C33F.DEC99C18_at_lehrer.uni-karlsruhe.de>

Tracy Latimer wrote:

> Bernd kindly posted last year what he found about weathering
> grades. I am attaching Bernd's post... thanks once again, Bernd!

Hello Tracy, Mark, and List,

My pleasure!

As for shock stages, here goes:

STÖFFLER D. et al. (1991) Proposal for a revised petrographic shock
classification of chondrites (Meteoritics 26-4, 1981, A398-A399):

S1 (unshocked) - sharp optical extinction of olivine

S2 (very weakly shocked) – undulatory extinction of olivine

S3 (weakly shocked) – planar fractures in olivine

S4 (moderately shocked) – mosaicism in olivine

S5 (strongly shocked) – isotropization of plagioclase
(maskelynite) and planar deformation features in olivine

S6 (very strongly shocked) – recrystallization of olivine
and phase transformations of olivine (ringwoodite)


Signed:

"Bernd the disgustingly well-informed" :-)
Received on Mon 02 Sep 2002 03:59:59 PM PDT