[meteorite-list] University of Toronto Talk by Christopher Charles Age of the Solar System?

From: tett <tett_at_meteoritecentral.com>
Date: Thu, 11 Jan 2007 21:47:09 -0500
Message-ID: <000a01c735f3$f474aa40$0202a8c0_at_Tettenborn>

List,

Below is an email from Roman Jirasek.

Very interesting.


Hi Mike, can you post the following to the list please? My settings are
screwed up and can't post this. I tried this morning but didn't see it in
the archives. Thanks man. - Roman


Last night my wife and I attended a talk about Calcium Aluminium-rich
Inclusions in stony meteorites at the University of Toronto. The speaker
was Christopher Charles, a 2nd year Ph. D. student at the Department
of Geology, University of Toronto.

He starts off with basic meteorite knowledge and then gets into the
chemistry and dating of meteorites using radioactive "clocks". Then
concluding with the suggestion that CAI's may be much older that
previously thought, and that the solar system may also be much older.

It was very interesting, with a good use of visual information,
pictures/graphs. People were told to bring meteorites to display
before and after the talk, which several of us did. I met Jeffrey Shallit,
another Jeff that attended my meteorite party several years ago, and
Patrick Herrmann, (a world class collection owner).

Here is the speakers abstract:

Some of the most intensely studied natural materials include
the three meteorite families (stones, irons, stony-irons) which harbor
a number of radioactive "clocks" locked in phases of these objects at
their formation. Stony meteorites are particularly important since they
enclose the oldest dated phases, the calcium-aluminium-rich inclusions
(CAIs) at 4567.4 Ma, which define the precise age of the Solar System
(Amelin et al. 2002). However, ages of the earliest known stony
(achondritic)
rocks, the angrites, are questioning this Solar System age defined by
CAIs, suggesting it is actually much older. This significant finding is
"turning back the clock" on the birth of the Solar System, which may
potentially require a re-calibration of all other short-lived radioactive
clocks like 182Hf-182W, etc. In this talk I will review the three main
classes of meteorites and their properties, then focus on stony meteorites
and discuss why the lead-lead ages of angrites and CAIs are revolutionizing
our understanding of exactly when the Solar System actually formed. This
presentation should offer an interesting overview on meteorites and the
origin of the universe!

All in all a worthwhile trip into the city.
My thanks goes out to Jeffery Shallit and Mike Tettenborn for letting me
know about the talk. Mike could not make his long drive, how much
snow ya got up there?

Best regards,

Roman Jirasek
www.meteoritelabels.com
Received on Thu 11 Jan 2007 09:47:09 PM PST