The P-Tr meteorite

["David Marjanovic" <david.marjanovic@gmx.at>]

Now look at that http://www.nature.com/nsu/010920/010920-6.html.

"Kunio Kaiho of Tohoku University, Japan, and his colleagues have found
evidence in southern China that a massive impact converted huge amounts of
solid sulphur into sulphur-rich gases.
        The released sulphur could have consumed 20-40 per cent of the
atmosphere's oxygen, and generated enough acid rain to raise the acidity of
the ocean's surface waters temporarily to that of lemon juice. Ocean life
would have been pickled."

Even worse than the K-T Strangelove ocean. Incredible.

"Now Kaiho's team has found sulphate in end-Permian limestone, marl and
shale rocks formed from shallow sea-floor sediments. The rocks also have a
nickel-rich layer, which could have been carried by an impacting meteorite.
Moreover, in the nickel-rich layer, the researchers detect a sudden change
in the relative amounts of different sulphur isotopes (whose atoms have
slightly different masses).
        If a giant meteorite impact vaporized a large area of
sulphur-containing rock where it struck the seabed, it would probably have
ejected the lighter of sulphur's two common natural isotopes into the air,
changing the isotope ratio of the remaining rocks.
        From the size of isotope ratio shift, Kaiho's group estimates that
the meteorite could have been up to 60 kilometres across. The
Cretaceous-Tertiary meteorite was probably less than 10 km across."

That went fast, eh? A few months ago we celebrated that we knew that
_something_ impacted at that time, and now we can already estimate the size
and composition of the bolide.

Ref:
Kaiho, K. et al. End-Permian catastrophe by a bolide impact: evidence of a
gigantic release of sulfur from the mantle. Geology, 29, 815 - 818, (2001).