[meteorite-list] Hoba - historical notes

From: Mark's Meteorites <mark_at_meteoritecentral.com>
Date: Thu, 12 May 2011 11:29:58 +0100
Message-ID: <1200044F-287F-4263-AE7B-7227AF427F99_at_meteorites.cc>

Hi all,

I've added a new addition to my historical site with details of the circumstances of the find of the Hoba mass. As you know, Hoba is the largest known meteorite specimen in the world.

http://historicfalls.com/20th-century/hoba/

One passage intrigued me:

"For the purpose of determining the magnetic axis of the meteorite a six-foot length of steel drill was magnetised, and Mr A W Clark found that the axis is about 14deg east of the earth?s present magnetic axis. No doubt the meteorite became magnetised in the earth?s field when it fell with a violent concussion; but whether it would be possible to deduce from this figure the date of the fall is very doubtful."

The terrestrial age of Hoba is generally given as around 80,000 years. This is more than enough for the magnetic field to have wandered by this amount. I know field orientation is used in geology to correlate ages of some beds with the earth's field.

Is this approach to verifying terrestrial age one that has been tried, and are there any good reasons why it would/wouldn't work?

Mark Crawford
Received on Thu 12 May 2011 06:29:58 AM PDT