[meteorite-list] Hoba

From: Bernd Pauli HD <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 09:48:14 2004
Message-ID: <3BDF3A4C.B6C77FC_at_lehrer1.rz.uni-karlsruhe.de>

Matt wrote:

> (hoba) is between 200 and 400 million years and
> it fell on Earth approximately 80 000 years ago.
> 200-400 Ma seems "young" for an iron! Is this valid?


Hello Matt and List!

BUCHWALD V.F. (1975) Handbook
of Iron Meteorites, Volume 2, p. 648:

a) Bauer (1963) measured the 3He/4He concentration and
    estimated the cosmic ray exposure age to be 190 million
    years.

b) Voshage (1967) found the 40K/41K ratio to correspond to
     300±110 million years., while Lämmerzahl & Zähringer (1966)
     found 1030±300 million years by the 40A/38A method, a
     method which apparently here is somewhat in error.

c) McCorkell et al. (1968) found a 36Cl/36Ar exposure age of
    263±40 million years.


Best wishes,

Bernd
Received on Tue 30 Oct 2001 06:39:56 PM PST