Amber Listserv / IOL: Volcanoes may have killed off dinosaurs

[Paul Howell]

The eruptions of the Deccan Traps began before the Chicxulub impact,
and continued long (several million years) afterward.  There remains
little argument that the Chicxulub impact directly and indirectly
caused the most devastation and extinctions for the K-T boundary.
The volcanic activity of the Deccan Traps was a big suspect prior to
the discovery of the iridium anomaly and the hunt for the impact that
caused it (eventually being identified as Chicxulub).  All this new
study says is that yes, there is direct evidence for bad gases in the
atmosphere resulting from Deccan activity... as always suspected there
were.  There was much much worse injected from Chicxulub.

A decent synopsis of the Traps:  http://en.wikipedia.org/wiki/Deccan_traps

Cheers,
Paul


On Tue, Mar 25, 2008 at 12:53 PM,  <tamber12 at aol.com> wrote:
> And is there any mention of a way to determine if these volcanic events
> happened before, after or as a result of the Chixilub event? Are the Deccan
> Traps deposits above, below or consistent with the K-T boundary? I still
> think the K-T boundary and irridium levels are fairly good evidence of the
> impact theory.  Anyone else?
>
>  Tam
>
>
>
>
>  -----Original Message-----
>  From: JOHN FUDALA <ambersafari at gmail.com>
>  To: amber at ambericawest <Amber at ambericawest.com>
>  Sent: Tue, 25 Mar 2008 11:46 am
>  Subject: Amber Listserv / IOL: Volcanoes may have killed off dinosaurs
>
>
> There we go again...
>
>    Reuters
>      March 22 2008 at 10:55AM
>
>  Gas-belching volcanoes may be to blame for a series of mass extinctions
> over the last 545-million years, including that of the dinosaurs, new
> evidence suggested on Thursday.
>
>  A series of eruptions that formed the Deccan Traps in what is now India
> pumped huge amounts of sulphur into the atmosphere 65-million years ago,
> with likely devastating repercussions for the Earth's climate, scientists
> said.
>
>  Gigantic eruptions, forming so-called "flood basalts", are one of two
> leading explanations for a series of mass extinctions that have killed off
> species periodically throughout history.
>
>  The other theory involves asteroid impacts - generally considered the prime
> suspect in the case of the extinction of dinosaurs 65-million years ago.
>
>  There have been doubts about the killing power of volcanoes because, until
> now, researchers have struggled to measure just how much toxic gas would
> have been released.
>
>  But after finding rare inclusions of glass in the Deccan rock, a
> British-based team has found vital preserved information about its original
> gas content. Writing in the journal Science, they concluded that the massive
> of amounts of both sulphur and chlorine released would probably have had a
> "severe" environmental impact.
>
>  The volcanoes may have spewed 10 times as much sulphur into the atmosphere
> every year as humans have done recently by burning coal in power stations
> and through other industrial activities.
>
>  The result would have been widespread acid rain and aerosols of sulphuric
> acid in atmosphere, cooling the surface of the Earth and upsetting
> circulation patterns.
>
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