[meteorite-list] Meteorite Question

From: rochette <rochette_at_meteoritecentral.com>
Date: Thu Apr 22 10:00:06 2004
Message-ID: <v03007801b955ee3ac6f5_at_[193.250.251.153]>

Dear Rhett,Bernd and list

In general when obtaining a measurement outside the norm (here Fa% for H
within 17-20), the inference "this is an anomalous meteorite" should not
be put forward before answering the questions:

-does the norm apply to this case? (obviously not for type 3 which by
definition show a large range in Fa%, with an average showing a standard
deviation of several %)
-then is there systematic bias? (possible for weathered finds, oxidation of
olivine starts by turning Fe to rust therefore decreasing Fa%)
-is the Fa% measurement well calibrated and what is the error bar? (It is
really difficult to get absolute precision below half a percent for this
parameter)
-is the studied sample representative?
-is the meteorite correctly classified? (possible case of Oviedo which may
turn to be an L)

excluding type 3, finds and incompletely classified meteorites and allowing
for a half percent error leave practically no anomalies in Bernd's list!
By the way why is Burnwell not fully classified?


Pierre
Received on Sat 13 Jul 2002 10:22:42 AM PDT