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Elton: Meteor May Not Have Destroyed Dinosaurs Afterall?

Hello Elton - 

     I'm wondering if you happen to have at hand from
your explosives knowledge the atmospheric pressure at
which lungs rupture?  How exactly does it compare with
the overpressures generated by the K-T impact event?

EP

--- Louis Varricchio <varricch@aero.und.edu> wrote:
> Dino Deaths Revisited:
> Meteor May Not Have
> Detroyed Them, After All 
>  
> By Kenneth Chang
> ABCNEWS.com
> 
> T A L A R N, Spain, Sept. 26 ¯
> 
> Maybe it wasn¢t a meteor, after all, that killed off
> the dinosaurs.  According to one paleontologist,
> dinosaurs continued to live for hundreds of
> thousands of years after that event, at least in one
> part of China. 
> 
> Many paleontologists considered the case of the
> dinosaur extinction closed as of 65 million years
> ago, when a large meteor slammed into Earth. Dirt
> and dust tossed up by the impact blotted the sun,
> and the resulting chill shoved the dinosaurs into
> evolutionary oblivion.  Geologists had found the
> equivalent of gunpowder burns ¯ a layer of the
> radioactive element iridium,
> commonly found in meteors ¯ detected in rocks around
> the world dated to this time. 
> 
> They even found the gunshot wound - a huge crater
> off Mexico¢s Yucatan peninsula.  Except there were a
> few nagging details that didn¢t quite fit the
> picture. 
> 
> 
> Other Pieces to the Puzzle
> 
> Many believe dinosaurs were already in decline for
> millions of years before the supposed impact. There
> was also another suspect ¯ massive volcanic
> eruptions that spewed noxious gases into the air and
> buried much of India in lava flows a couple of miles
> deep over several million years. Volcanoes can also
> be a source of iridium. Next theory: Maybe shock
> waves from the meteor impact traveled through the
> Earth, triggering the Indian             eruptions,
> which occurred almost exactly at the other side of
> the planet from the crater site. 
> 
> That explanation doesn¢t work, either. Radiometric
> dating of the lava flows indicate they started long
> before the meteor impact. So maybe dinosaurs 
> were just unlucky. The volcanic eruptions triggered
> climactic             changes that caused their
> decline, and the meteor impact was just the coup de
> grace that finished them off. 
> 
> Now Zikui Zhao of the Institute of Vertebrate
> Paleoanthropology in Beijing suggests the meteor
> didn¢t even do that. At the First International
> Symposium of Dinosaur Eggs and Babies in Talarn,
> Spain Saturday,
> Zhao presented evidence of dinosaurs laying eggs
> long, long after the meteor impact. 
> 
> Fossilized Eggs Tell Story
> 
> Near the town of Nanxiong in southeastern China,
> Zhao has uncovered numerous nests of fossilized
> dinosaur eggs.
> 
> Because sediments accumulate over time, the lower
> part of a rock is generally older. And in the lower,
> older rocks, he found 11 different species of eggs. 
> 
> The last period of dinosaurs is known as the
> Cretaceous, the period that follows is the Tertiary,
> and the time of mass extinctions that divide the two
> is called the K/T boundary. 
>                       
> At the point in the rocks that Zhao believes
> corresponds to the K/T boundary, six of the dinosaur
> species disappear. Eggs of this period also show a
> spike in levels of iridium, as well as other rare
> elements. 
> 
> However, *the remaining five species overstep the
> boundary and survive,* Zhao says. Indeed, he finds
> eggs well above the K/T boundary, suggesting that
> dinosaurs lived for several hundred thousand years
> longer than
> paleontologists thought. 
> 
> Questions Arise on Dating
> 
> Other scientists attending the symposium questioned
> his dating. *It is not the K/T boundary,* says
> Nieves Lopez-Martinez of Universidad Complutense in
> Madrid, Spain. The extinctions and iridium spike,
> she says, comes                from an earlier
> period of climactic change and possibly volcanic
> eruptions, about 71 million years ago, which she has
> detected in rocks in Spain, *not only here, but many
> other places in the world.* 
> 
> *He definitely has an anomaly,* says University of
> Colorado researcher Emily Bray, but she adds, *I
> think his boundary is too low.*  Others were also
> skeptical, because the rocks surrounding the
> Nanxiong eggs did not show a rise in iridium
> amounts. 
> 
> Zhao counters that his data also shows the earlier,
> smaller iridium spike and that rivers and rainfall
> dispersed the iridium over millions of years.       
>                The data also argues against the
> meteor-killed-all-the-dinosaurs scenario, Zhao says.
> Iridium levels jumped up in three separate spikes
> near the
> K/T boundary, something that could not be caused by
> a single meteor impact. 
>  
> Almost half of the eggs near the boundary show
> defects in their microscopic structure, which Zhao
> attributes to the high levels of the iridium and
> other trace elements. And those may be the true
> dinosaur killers. 
> 
> *The cause may have been environmental poisoning and
> adverse changes in climate,* Zhao says, and he
> points to the massive volcanic eruptions in India as
> the probable source. 
> 
> If Zhao¢s dating of his eggs proves correct,
> paleontologists will have to reopen their
> investigations into what killed the dinosaurs. 
>              
> Copyright ©1999 ABC News Internet Ventures. 
>                                                     
>                       
> 
> 
>  
> 
> LOUIS VARRICCHIO
> Environmental Information Specialist/Research
> Associate
>  Upper Midwest Aerospace Consortium
>  Odegard School of Aerospace Sciences
>  University of North Dakota
>  Grand Forks, N.D. 58202-9007
>    Phone: 701-777-2482
>    Fax: 701-777-2940
>    E-mail: varricch@umac.org (in N.D.)
>               morbius@together.net (in Vt.)
> 
> "Climate is what you expect, weather is what you
> get."--Robert Heinlein 
> 
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