Supernovae and the Rise and Fall of Man

C, Vance Haynes on the Black mat:
http://georgehoward.net/Vance%20Haynes'%20Black%20Mat.htm


Also, some new info and a great discussion have been placed on
YouTube
he
http://www.youtube.com/view_play_lis...566C328E999E76

On Wed, 3 Sep 2008 07:24:42 -0700 (PDT), wrote:

Intreresting discussion, folks. However, the statement above is
incorrect. The black mat has been dated at 12,900 on most of the
known Clovis sites, by the dean of Clovis Archeaology, C. Vance
Haynes.

There is a high degree of uncertainty in matching carbon dates to actual
dates during this period. It remains a key problem in dating Clovis
sites in general. A lot more work remains to be done in this area.

The so-called black mat layers are interesting, and certainly strongly
suggestive of some sort of wide spread event. What is currently in short
supply, however, is evidence linking it to an impact of some sort.

In any case, please don't think I'm suggesting there's anything wrong
with the theory that the Younger Dryas is associated with an impact
event. While I think the current evidence argues against it, the theory
itself is perfectly valid, and there is enough evidence in favor of it
(or ambiguous interpretations of various observations) to make an
investigation well worthwhile.

My complaint here is with a few cases where the hype has gotten ahead of
the science, and where very unlikely things (iron in tusks, the Carolina
Bays as impact structures, a coincident population drop in North
American cultures) are tied to an event that hasn't even been shown to
have likely occurred.
_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

On Sep 2, 3:57*pm, Chris L Peterson wrote:
On Tue, 2 Sep 2008 12:34:04 -0700 (PDT), LarryG
wrote:

Have you actually read the book and examined the authors' thesis, or
are you pontificating and conflating their theory with the sensational
pseudoscience of the past?

I have the book (and I've read it). I've also read the original
Firestone, West, et al publication, and have followed the scientific
debate closely (my own specialty is meteoritics, although not
specifically impact studies).

Excellent. We can now have an informed debate about the subject.


As I said before, the evidence remains thin. There is a layer of
ash-like material found at many sites. But the evidence for component
materials that are of likely extraterrestrial origin is lacking in most
sampled sites. Also, common dating of the layer in different areas is
not established.

The bulk of the mat is, according to the authors, thought to be
composed primarily of two things:
1. ash -- from the grass- and forrest-fires ignited by the explosion/
impact or its ejecta
2. dead algae -- which grew in great abundance after the melted ice
sheets and tsunamis saturated the Earth's atmosphere for several
weeks, if not months. The event would have killed most of the algae's
predators, and thus grew unconstrained until it had depleted the
resources necessary to sustain it.

The small spherules not withstanding, the investigator made no claim
that the mat was comprise, in any significant degree, of
extraterrestrial materials.

As for the common dating of the mat, are you suggesting that the mat
might have different ages at different sites? It is my understanding
that the mat is common to most Clovis sites, and marks a termination
layer below which extinct megafauna remains are found, and above which
they are not. It seems most likely that these mats were formed at
more or less the same time, and owed their origins to the same event.

Would you also claim that the Iridium rich K-T boundry layer,
associated with the impact-related demise of the dinosaurs, might also
be attributed to different events at differing times?




The book makes links to certain other things (the iron in tusks is just
ludicrous- widely recognized as completely misinterpreted,

Would you care to provide the correct interpretation, and your source.

quoting from: http://ie.lbl.gov/mammoth/impact_old.html
"Abstract: We have discovered what appear to be micrometeorites
imbedded in seven Alaskan Mammoth tusks and a Siberian bison skull.
The micrometeorites apparently shattered on impact leaving 2-5 mm
hemispherical debris patterns surrounded by carbonized rings. Multiple
impacts are observed on only one side of the tusks and skull
consistent with the micrometeorites having come from a single
direction. The impact sites are strongly magnetic indicating
significant iron content. We analyzed several imbedded micrometeorite
fragments from both tusks and skull with Laser Ablation Inductively-
Coupled Plasma Mass Spectrometry (LA-ICP-MS) and X-ray Fluorescence
(XRF). These analyses confirmed the high iron content and a uniform
composition highly enriched in nickel and depleted in titanium. The Fe/
Ni and Fe/Ti ratios are comparable to urelite meteorites and are
unlike any terrestrial sources. Prompt Gamma-ray Activation Analysis
(PGAA) of a micrometeorite extracted from the bison skull indicated it
contained ~0.4 mg of iron, in agreement with a micrometeorite ~1 mm in
diameter. Several tusks have an average radiocarbon age of ~33 ka.
This age coincides with sudden increases in global radiocarbon ~35 ka
agoa and 10Be ~32 ka agob, the Mono Lake geomagnetic excursion ~34 ka
agoc, and significant declines in Beringian bison, horse, brown bear,
and mammoth populations and genetic diversity 36 ka agod. The bison
skull shows evidence of new bone growth over the micrometeorite impact
sites indicating the animal survived the bombardment and is dated at
~26 ka which is younger than the tusks. This age is consistent with
exposure of the bison to an enriched source of radiocarbon following
the impact. It appears likely that the impacts, cosmogenic isotope
increases, magnetic excursion, and population declines are related
events (Occam’s razor), although their precise nature remains to be
determined."

but the idea
that the Carolina Bays is related to an impact is very weak,

The book provides a convincing argument that they are the result of at
least secondary, if not primary impacts.
1. Their elongation and relatively shallow depth are the result of
impact of low density / low cohesion bodies, with a low angle of
incidence.
2. The major axes of elongation are essentially parallel to nearby
Bays/craters.
3. Across wider areas, the major axes point toward two common sources
- one being (near) Lake Michigan, the other in upper Canada, perhaps
Hudson Bay.
4. The Bay/crater rims possess sizable quantities of the small
magnetic spherules characteristic of the clovis sites' extinction
layer.


as is the
association between the Younger Dryas and an impact.

The last "regular" period of glaciation was just ending when the
Younger-Dryas quickly reversed the warming trend. You know very well
that some mechanism must have come into play for that to have
happened. From the evidence and the arguments presented in the book,
I believe that the supernova-comet impact sequence best explains not
only the glitch in glaciation, but the dozen of other paleological,
anthropological, and biological changes which happened around that
time period.



In addition, I read
a paper just a few weeks ago that rather solidly demonstrated no common
time of population decline in North American cultures between 9 and 15
thousand years ago. That is, no evidence of a single event causing
population loss.

Yes, I have read of this finding, and admit that it is surprising. If
paleoamericans hunted mammoths and other large creatures as essential
to their food supply, then the disappearance of these creatures should
similarly decrease the number of humans around. Of course, people are
much more adaptable than typical predators, and may have overcome the
adverse circumstances without much effect on their own numbers. I
don't see this as strongly weighing against the supernova/comet impact
sequence theory, but it is indeed an interesting observation.


In any case, the possibility that the Younger Dryas was caused by an
impact is a viable theory that is currently being investigated, but is
not well accepted by the majority of the meteoritical, impact,
archaeological, or paleontological communities.

IIRC, Luis Alvarez met with a chorus of criticism when he proposed
that an asteroid killed off the dinosaurs. Twenty-five years later,
his theory is taken for granted. I suspect that much the same will
happen with this theory. To me, it explains a great deal more than
the Younger Dryas, and in doing so, helps me to make sense of our
past.


That doesn't mean it's
wrong, only that it needs a lot more work, and a few people are getting
way ahead of themselves in pushing the idea- in particular, trying to
connect it to geophysical and archaeological elements that are much
better explained by other things. What's needed isn't speculation (in
some cases wild speculation), but a lot more raw data, mainly in the
form of material samples.

There are many benefits that this book should bring to the public:
1. It shows that scientists are real people, whom the general public
might actually be able to relate to - digging in the dirt, asking
questions, playing hunches, playing with a shotgun, etc.
2. It gives a real world example of sciece, and the scientific method,
at work.
3. It can get lay people excited about science, astronomy, and the
history our ancient human ancestors lived through.
4. It can tell us that if our ancestors survived an apocalyptic
devastation, then perhaps there is hope that we can too, should the
need ever arise.

Carl Sagan was often criticized when he first started writing popular
science. But I think he well served both the lay and the scientific
communities in doing so.

And compared to some other works that I have read, and read of, about
this vague era in human history, I would much rather have stimulation
that has much more scientific merit, than the tomes of trash which do
not.

Cheers,
Larry G.

_________________________________________________

Chris L Peterson
Cloudbait Observatoryhttp://www.cloudbait.com

LarryG wrote:
On Sep 2, 3:57 pm, Chris L Peterson wrote:
On Tue, 2 Sep 2008 12:34:04 -0700 (PDT), LarryG
wrote:

Have you actually read the book and examined the authors' thesis, or
are you pontificating and conflating their theory with the sensational
pseudoscience of the past?
I have the book (and I've read it). I've also read the original
Firestone, West, et al publication, and have followed the scientific
debate closely (my own specialty is meteoritics, although not
specifically impact studies).

Excellent. We can now have an informed debate about the subject.

That's such a classic usenet statement.

Obviously Chris (and presumably others) know quite a bit about this
subject whether or not they have read this particular book. Maybe when
you guys stop thumping your chests--that's when we can have the informed
debate...

(e.g. never)

--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools: http://www.skyhound.com/cs.html
Observing: http://www.skyhound.com/sh/skyhound.html
Comets: http://comets.skyhound.com

To reply take out your eye

On Wed, 3 Sep 2008 10:16:20 -0700 (PDT), LarryG
wrote:

Excellent. We can now have an informed debate about the subject.

Perhaps we could, but I'll pass. This is a subject I'm familiar with,
and my current opinions are based on my reading of the evidence
presented so far. I'm perfectly open to the idea of a Holocene impact.
But right now, I'll just let those who are specializing in this research
continue collecting observations, because I don't think these "debates"
are particularly useful without more data.
_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Chris L Peterson wrote:

Perhaps we could, but I'll pass. This is a subject I'm familiar with,
and my current opinions are based on my reading of the evidence
presented so far. I'm perfectly open to the idea of a Holocene impact.
But right now, I'll just let those who are specializing in this research
continue collecting observations, because I don't think these "debates"
are particularly useful without more data.

So, to sum up this thread:

"You're wrong, but I'm not going to argue with you."

Hmmm... ;-)

On Wed, 03 Sep 2008 15:04:37 -0400, "Richard F.L.R.Snashall"
wrote:

So, to sum up this thread:

"You're wrong, but I'm not going to argue with you."

I'm certainly not saying anybody is wrong.
_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Hey guys. Sorry to be a crank, but if you look here I think you would
find the additional evidence, and challenges made to theory,
interesting.

See:
http://www.youtube.com/view_play_lis...566C328E999E76