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Re: Dino extinction



Sherry Michael wrote:
>Sure, maybe a catastophe. Did it cause the extinction? Were not even sure
>it was a extraterrestrial body. We don't even have a good crater site that
>can be proved. The only thing we have is some trace element around the
>world the time dinosaurs died out. Now, prove to me that they didn't die
>out a thousand years before the "meteor" hit. Or even that there was one
>at all. We need to prove cause and effect.

Sherry, I'm curious. How much research have you actually done on this?
I have a theory that if people would only become familiar with the latest
published research on the K/T, they would overwhelmingly support the
bolide theory. There is simply no other way to account for the anomalous
values of the thing you casually brush off as "some trace element". It
happens to be Iridium, which is relatively rare in the earth's crust but
common in asteroids and comets. (There are actually a group of elements 
like this called siderophiles.) The Alvarez team's original goal when
analyzing the boundary clay was to determine how long it took to deposit
it. Luis had a theory that because there is a steady rain of meteors from
space, there is a sort of "salt shaker" effect of Iridium/siderophile
enhancement going on all the time. By measuring the the Iridium content 
of the clay, they could estimate the time it took to deposit it. When they
discovered this huge anomaly, the research took a quick turn as they 
focussed on what could create such a curious anomaly in the geologic
column. They concluded that a volcanic origin is not possible. The
only palatable scientific explanation left was the bolide theory. This
all happened in the early 1980's. Ten years of research has added an
enormous amount of discoveries which bolster the Alvarez conclusion.
Alot of the new evidence has already been referred to or posted here.
Go back and re-read Jack Alroy's refutation of the Meyerhoff paper.
I could also mention dozens of references about siderophile ratios
being typical of asteroids/comets, the prescence of abundant microtektites, 
tsunami deposits around the Gulf of Mexico, the soot layer part of the 
boundary clay in some areas. There is so much corroborating evidence for
the Chicxulub impact that it's frankly getting difficult to understand 
why there is even a dispute about whether an impact occurred. The area
we should direct our attention to is modelling the effects of the impact.

[ref to the Chicxulub impact crater]
Sherry Michael wrote:
>There is increasing doubt that it is an impact site at all. 

BZZZTTT! Wrong. Thank you for playing. You should have said *decreasing*
doubt that is an impact site. But don't believe me, I encourage readers 
out there to read about it for themselves in Science, Nature, Science News, 
Earth, Discover, Scientific American  or whatever they read. The consensus 
in the scientific community supports the bolide theory, especially among 
those who are familiar with the latest research. 

Sherry Michael wrote:
>Also, someone out there clarify for me; my foggy head
>remembers hearing that people just didn't look too hard for dinosaur
>fossils after the K/T, and just now the scienctist have started looking for
>them. Anyone know what I'm talking about?

As I've said, small, intelligent Tertiary dinos wouldn't come as a surprise.
However, only a few scattered teeth have been found in Tertiary deposits,
and from the context were explicable as having eroded from Cretaceous rocks.
I assume you are looking for some evidence that the end of dinos does not
correlate to the K/T boundary clay. There is sufficient sampling to state
that few, if any dino fossils occur above the K/T boundary.

[ref to dino extinction being correlated to K/T boundary]
Sherry Michael wrote:
>The only problem I have of this theory is it has been popuarized as
>trumpeted as a fact and not a theory. I really see no compelling evidence
>to put together a cause-effect realtionship. 

Maybe someday, Sherry, you will pick up an old Scientific American
and look closely at the nice full-page color photo of the Gubbio, Italy
K/T section. You will notice the forboding, black, Iridium-rich boundary
clay sandwiched between otherwise nice, white marine carbonate rock.
In your mind, you integrate all the evidence, measurements, knowledge
that 50% of living organisms don't cross this boundary in the fossil
record, and suddently it will hit you. My God, it really happenned!

But then again, maybe not. I guess you can lead a horse to water but 
you can't make them see compelling evidence.