[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Asteroid impact finally confirmed?
Mark O'Leary wrote:
> Firstly to disagree with your subject. It wasn't a case of "finally
> confirmed" - the impact has been known and accepted for a long time.
Not by everybody, it seems. THE GREAT DINOSAUR EXTINCTION CONTROVERSY
(Officer & Page, 1996) claims that not only has much of the evidence
been misinterpreted, some of it has been ... hmm, how to say it?
"invented" is too strong . . . maybe "seen when it wasn't really
there." Their case is damaged by the fact that they aren't fully
conversant with the theory they're criticizing, but IAC they claim to
have old studies that show the Chicxulub crater is no crater at all.
Even if it was a crater, they say, it couldn't be THE crater because it
contains a continuous sequence of Cretaceous-to-Tertiary sediments.
> It sounds like you are envisioning the day of the impact as being the
> of the wipeout. Sure maybe continents-worth of creatures got wiped out
> the firestorm, but the main killer would be the century or so of low
> and wintry conditions that having a dust-laden stratosphere would
> Certain plants would die completely, surviving only as seeds in the
> Others would become dormant, not fruiting or flowering. The creatures
> depended on these plants for food or shelter would perish with them.
Centuries, decades, or only a year or two, I can't see that it makes
much difference. To my eyes, the K-T extinction still seems to show the
wrong pattern for a "worldwide darkness"-induced event. All Cretaceous
mammals were small, right? Small endotherms all have one feature in
common: they have to eat a _lot_ of food to keep going. No plant
reproduction, and they'd eat up every shred of greenery real quick. So
what kept them fed until the atmosphere cleared and the plants started
growing again? The same is true for the birds.
Something here is not making sense. I can't believe that none of this
has ever been considered, but I've never seen a good answer to it.