[meteorite-list] Mass Extinctions -- A Threat from Outer Space orOur Own Planet's Detox?

From: Mark <mafer_at_meteoritecentral.com>
Date: Thu Mar 9 16:11:13 2006
Message-ID: <007c01c643bd$f4530800$02fea8c0_at_maf>

Hi Rob and List

Actually, as far as I know (reading and specific tv documentaries by
paleontologists), there isn't a dinosaur fossil within 100K years or more of
the iridium layer, that's before it was laid down. The exceptions are the
birds. And that's another story.

But, all the data collected on a "mass" extinction at 65 mya is based
largely on micro-marine fossils. The work on these fossils had been done by
many different geology types, and the data they provide is then picked up by
astro-physicists who calculate the numbers required to satisfy what they
want to see.
One team even goes so far as to say that the energy released 65 mya at
Chixulube, was enough to blow off the ozone layer 1000 times over. I did ask
them, "With so much energy released, how did any life form survive?" and I
got, "..well, the animals that could survive underwater or burrow would have
survived." hmmm, I then asked them "how deep a burrow and for how long would
they have had to stay in it and what about plants?"

They didn't answer. All the "impactor killed the dinosaur" theories are
based on one point of view. That of the dinosaurs dying out because of an
impactor with little thought how anything else survived or why anything else
survived. Except, of course, for the micro-marine organisms which all died
out world wide also.
There is no evidence what so ever that any dinosaurs died as a result of the
Chixulube impact event. It is all fabrication on the part of
non-paleontological scientists because of that nice number which divides the
Cretaceous from the Paleocene.

Mark Ferguson

----- Original Message -----
From: "Rob McCafferty" <rob_mccafferty_at_yahoo.com>
To: <meteorite-list_at_meteoritecentral.com>
Sent: Thursday, March 09, 2006 12:31 PM
Subject: Re: [meteorite-list] Mass Extinctions -- A Threat from Outer Space
orOur Own Planet's Detox?


I didn't think this was a new idea. In fact there have
been TV drama/documentaries (docudramas) made about
the possibility of Yellowstone doing precisely this. I
think it was caled "Supervolcano" or something
similar.

There is also the predicted impact frequency to think
about for meteorites of about that size. They keep
saying we're overdue the next one (every 50million
years or so). Think about it, though. The dinosaurs
were around for 150 million years so this means they
survived at least 1 (statistically more), they also
had a stay of execution much longer than our own
currently is or we have our size distributions
horribly wrong.

Now I don't think its the third one, I've seen the
numbers and the second is not likely either. Both
those being the case, we need a different explanation.
Besides which, isn't there evidence that dinosaurs
survived for several million years after the iridium
layer was layed down 65Ma?

As an aviation enthusiast, I have noticed that air
disasters are rarely the result of one error. There's
usually a catalogue which leads to catastrophe. Is it
not likely that many mass extinctions are due to a
similar thing?
If the geologists are right, the 65Ma mass extinctions
were small compared to one of the earlier ones where
over 90% of all species vanished. That somehow seems
significant, though quite why eludes me.

Rob McC


--- Ron Baalke <baalke_at_zagami.jpl.nasa.gov> wrote:

>
>
> Press and Publications Office
> University of Leicester
> Leicester, U.K.
>
> 09/03/2006
>
> Mass Extinctions -- A Threat from Outer Space or Our
> Own Planet's Detox?
>
> University scientists suggest extraterrestrial
> theories are flawed and
> that more down to earth factors could have accounted
> for past mass
> extinctions
>
> Earth history has been punctuated by several mass
> extinctions rapidly
> wiping out nearly all life forms on our planet. What
> causes these
> catastrophic events? Are they really due to
> meteorite impacts? Current
> research suggests that the cause may come from
> within our own planet --
> the eruption of vast amounts of lava that brings a
> cocktail of gases from
> deep inside the Earth and vents them into the
> atmosphere.
>
> University of Leicester geologists, Professor Andy
> Saunders and Dr Marc
> Reichow, are taking a fresh look at what may
> actually have wiped out the
> dinosaurs 65 million years ago and caused other
> similarly cataclysmic
> events, aware they may end up exploding a few
> popular myths.
>
> The idea that meteorite impacts caused mass
> extinctions has been in vogue
> over the last 25 years, since Louis Alverez's
> research team in Berkeley,
> California published their work about an
> extraterrestrial iridium anomaly
> found in 65-million-year-old layers at the
> Cretaceous-Tertiary boundary.
> This anomaly only could be explained by an
> extraterrestrial source, a
> large meteorite, hitting the Earth and ultimately
> wiping the dinosaurs --
> and many other organisms -- off the Earth's surface.
>
> Professor Saunders commented: "Impacts are suitably
> apocalyptic. They are
> the stuff of Hollywood. It seems that every kid's
> dinosaur book ends with
> a bang. But are they the real killers and are they
> solely responsible for
> every mass extinction on earth? There is scant
> evidence of impacts at the
> time of other major extinctions e.g., at the end of
> the Permian, 250
> million years ago, and at the end of the Triassic,
> 200 million years ago.
> The evidence that has been found does not seem large
> enough to have
> triggered an extinction at these times."
>
> Flood basalt eruptions are -- he says -- an
> alternative kill mechanism.
> These do correspond with all main mass extinctions,
> within error of the
> techniques used to determine the age of the
> volcanism. Furthermore, they
> may have released enough greenhouse gases (SO2 and
> CO2) to dramatically
> change the climate. The largest flood basalts on
> Earth (Siberian Traps and
> Deccan Traps) coincide with the largest extinctions
> (end-Permian, and
> end-Cretaceous). "Pure coincidence?", ask Saunders
> and Reichow.
>
> While this is unlikely to be pure chance, the
> Leicester researchers are
> interested in precisely what the kill mechanism may
> be. One possibility is
> that the gases released by volcanic activity lead to
> a prolonged volcanic
> winter induced by sulphur-rich aerosols, followed by
> a period of
> CO2-induced warming.
>
> Professor Andy Saunders and Dr. Marc Reichow at
> Leicester, in
> collaboration with Anthony Cohen, Steve Self, and
> Mike Widdowson at the
> Open University, have recently been awarded a NERC
> (Natural Environment
> Research Council) grant to study the Siberian Traps
> and their
> environmental impact.
>
> The Siberian Traps are the largest known continental
> flood basalt
> province. Erupted about 250 million years ago at
> high latitude in the
> northern hemisphere, they are one of many known
> flood basalts provinces --
> vast outpourings of lava that covered large areas of
> the Earth's surface.
> A major debate is underway concerning the origin of
> these provinces --
> including the Siberian Traps -- and their
> environmental impact.
>
> Using radiometric dating techniques, they hope to
> constrain the age and,
> combined with geochemical analysis, the extent, of
> the Siberian Traps.
> Measuring how much gas was released during these
> eruptions 250 million
> years ago is a considerable challenge. The
> researchers will study
> microscopic inclusions trapped in minerals of the
> Siberian Traps rocks to
> estimate the original gas contents. Using these data
> they hope to be able
> to assess the amount of SO2 and CO2 released into
> the atmosphere 250
> million years ago, and whether or not this caused
> climatic havoc, wiping
> out nearly all life on earth. By studying the
> composition of sedimentary
> rocks laid down at the time of the mass extinction,
> they also hope to
> detect changes to seawater chemistry that resulted
> from major changes in
> climate.
>
> >From these data Professor Saunders and his team
> hope to link the volcanism
> to the extinction event. He explained: "If we can
> show, for example, that
> the full extent of the Siberian Traps was erupted at
> the same time, we can
> be confident that their environmental effects were
> powerful. Understanding
> the actual kill mechanism is the next stage ...
> watch this space."
>
> More information is available from the website:
>
> http://www.le.ac.uk/gl/ads/SiberianTraps/Index.html
>
> Note to editors:
>
> Further information is available from Professor Andy
> Saunders, Department
> of Geology, University of Leicester, tel 0116 252
> 3923; or from Dr Marc
> Reichow, email: mkr6 _at_ le.ac.uk .
>
>
>
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>
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>


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Received on Thu 09 Mar 2006 04:10:54 PM PST