Boats?

[Rokcet Scientist]

the speed at which they spread suggests that they did avoid conflict

How so, Roy? From 1,8 million years BP (Dmanisi) to 800,000 years BP (Java and Beijing) is a full million years. Do you consider that a 'speedy' diaspora? I don't.

[E.P. Grondine]

http://www.princeton.edu/pr/news/03/q3/0925-keller.htm

Keller and a growing number of colleagues around the world are turning up evidence that, rather than a single event, an intensive period of volcanic eruptions as well as a series of asteroid impacts are likely to have stressed the world ecosystem to the breaking point. Although an asteroid or comet probably struck Earth at the time of the dinosaur extinction, it most likely was, as Keller says, "the straw that broke the camel's back" and not the sole cause.

Perhaps more controversially, Keller and colleagues contend that the "straw" -- that final impact -- is probably not what most scientists believe it is. For more than a decade, the prevailing theory has centered on a massive impact crater in Mexico. In 1990, scientists proposed that the Chicxulub crater, as it became known, was the remnant of the fateful dinosaur-killing event and that theory has since become dogma.

Keller has accumulated evidence, including results released this year, suggesting that the Chicxulub crater probably did not coincide with the K/T boundary. Instead, the impact that caused the Chicxulub crater was likely smaller than originally believed and probably occurred 300,000 years before the mass extinction. The final dinosaur-killer probably struck Earth somewhere else and remains undiscovered, said Keller.

That evidence has to be dealt with.

It has been, Min, you just don't know it yet. Here is the quick backgrounder:

> From: sterling webb
> To: epgrondine at hotmail.com;
> Subject: Re: [meteorite-list] The COMET that killed the dinosaurs
> Date: Fri, 22 May 2009 17:30:14 -0500
>
> Dear Doug, EP, List,
>
> >Keller, who as a matter of fact does believe a shower
> >was likely involved and allows that it could have been
> >cometary and happened over a longer span of time...

> Doug, while touting a series of impacts as the cause of the K-T extinction for a few years, Keller now rejects any role for any impact, no matter how big... Well, sometimes she does... and sometimes not.

> The latest version of Kellerism presents the "view of the
K-T mass extinction mechanism where extraterrestrial
impact had no influence on the faunal mass extinction,”
http://www.dailyprincetonian.com/2009/05/06/23652/

>Keller has supported the volcanic theory since 2003:
http://www.sciencedaily.com/releases/20 ... 065930.htm

>She continues to do so today:
"The impact had little immediate effect on the planet’s biome.
Says Keller: “It didn’t kill the dinosaurs. In fact, it didn’t cause much damage that we can determine from the geological record [The Scientist]. “We found not a single species went extinct as a result of the Chicxulub impact,” says Keller."

http://blogs.discovermagazine.com/80bea ... xtinction/

>Not a single species. Didn't cause much damage. Check.

>While supporting, in some venues, the volcanic gas theory as the sole cause, she has also said "It was, instead, a progressive multi-event catastrophe, a concerted assault on the whole edifice of life by a combination of massive volcanism, multiple
impacts and their associated climatic and environmental changes."

http://www.geolsoc.org.uk/gsl/site/GSL/ ... /chicxulub

> [I don't know how she explains that, in the sedimentary layers between Deccan Trap basalt flows, there are dinosaur fossils. So, the Traps couldn't even kill the dinos that lived right on the same continent with them. OK. Back to Gerta's Story...]

> You will note that in this statement, she assigns impact an importance second only to the massive volcanism of the Deccan Traps, in her more recent statement she flatly asserts that impacts like Chicxulub don't "cause much damage." Elsewhere she has asserted that big impacts simply have no measurable effect on the Earth.

> But then, in 2006, she suggested that global warming weakened many species and that they were then extincted by another, bigger and yet undiscovered impact! "What the microfossils are saying is that Chicxulub probably aided the demise of the dinosaurs, but so did Deccan trap volcanism's greenhouse warming effect and finally a second huge impact that finished them off."
http://www.geosociety.org/news/pr/06-47.htm

> If I had a hammer...

> For those who bother to read these posts because they're interested in impacts, this must be confusing. Shall we bottom-line it?

>Let's do that.

> The debate is about ~20 inches of strata, gritty limey stuff that is found between the level of the impact and the time of the extinction in sites near to Chicxulub (Mexico, Texas). It's about whether 1.) that 20 inches is dead pulverized debris from the impact slammed across the landscape and/or deposited by one of the biggest tidal waves in the history of the planet OR whether 2.) it's quiet sediment with traces of undisturbed lifeforms in it.

> Almost everyone who studied it says it's #1. Keller says #2. The answer depends on close examination of the material, something both sides have done (for decades). The evidence of life or no life is forams or no forams.

> What's a foram?

> Foraminifera are microscopic marine creatures with tiny stony skeletons (just like us, only forams wear theirs on the outside). When they die, the stone shell remains. It can persist for millions or hundreds of millions of years. Some limestones are virtually made out of foram skeletons.

> So the tiny crystals in this limestone layer are either forams or they're just crystals, once-living or never-living. And inorganic crystals are hard to distinguish from organic ones except in exceptional close and precise examination, SEM, Xray, and the like. I suggested everybody look at the evidence in:
http://www.falw.vu/~smit/csdp/debates.htm
(not because I favor Smit but because his pictures of Keller's samples are bigger and clearer than on the GeoSociety website).

> What I see (and I mean that to emphasize my subjectivity) is that a lot of Keller's forams are NOT forams. For example, their "cell walls" do not have the pores of a living cell, while "real" forams do. And likewise, some of Keller's forams ARE forams.

> The problem of whether this means anything is this: even if Keller's forams were true once-living forams, it would not prove that they were alive when they were deposited in this strata, since foram skeletons persist for a very long time. The "real" forams in Keller samples could have been dead for a million years before they got there or they could have died in place and in peace.

> No way to tell.

> There are other baffles. Are the few burrows really burrows? Has life worked this strata over (bioturbulence) or not? Even that is not decisive. If this is impact debris, would not the few surviving living things be scrounging through it in sheer desperation in the weeks or months after the impact before they starved or were poisoned by the disrupted environment? When many creatures die, the eating is good... for a while.

> No way to tell.

> That it's a tense issue is because for Keller to be right, dozens of scientists in the same field have to be wrong. Not just wrong -- incompetent. And the only way to explain Keller being wrong is the same reason: she's incompetent. You can see why folks would get a little snippy in this lofty debate of noble science.

> Another point is this. The strata under discussion are all found close to the impact site (Mexico, Texas). In Spain, in China, in Africa, there is NO separation of impact layer and extinction layer. They lay on each other as flat as a strap with no intervening strata.

> Now, IF there was a 300,000 year gap between the impact and the extinction, wouldn't it show up EVERYWHERE in the world? Or, at a minimum, wouldn't show up SOMEWHERE else? And, the truth is -- it doesn't. Not anywhere. Not even in undisturbed ocean sediment. (See: MacLeod, K.G., Whitney, D.L., Huber, B.T.,
> Koeberl, C., 2007. Impact and extinction in remarkably complete K/T boundary sections from Demerara Rise, tropical western North Atlantic. Geol. Soc. Amer. Bull. 119 (1), 101–115.) They were unable to find the stony corpse of even one Cretaceous micro-organism above the impact layer in any core sample.

> Not one.

> Here's a summary of those results:

http://gsa.confex.com/gsa/2004AM/finalp ... _80313.htm
> And here's the full paper:
http://www.univie.ac.at/geochemistry/ko ... AB2007.pdf

> One impact. One extinction. Simultaneous (well, geologically anyway). Adieu, T. Rex.

> That's what the evidence seems to say. Well, that's what it says to 97% of all the researchers in the field. Or maybe it's 99%. People who don't like the idea of impact as a process like Keller; she plays to them. But then, those people don't study impacts. Nasty things. And they don't know much about them. Then, she turns around and suggests even bigger impacts.

> She gets a great deal of press but very few supporters. She's very popular among people with a "cultural" interest in science.

> Now me, I take the long view. Once there were dinosaurs. Now there are not. They all died out at about the same time, along with the wonderful ammonites. (Who weeps for the ammonites? You dinochauvinistes!) It doesn't exonerate the Killer Asteroid if it took a thousand years, 100,000 years, or a million years to kill the Dinos. Still guilty as charged.

> Did they die all once? Gasp, Flop? Did it take 5000 years? 10,000 years? (There seems to be a Dead Zone about that length.) 25,000 years (which is all that remains of Keller's 300,000 years)? And even Smit says it took 35,000 years...

> So, how many years are we arguing about? Any?

> What difference?

> No dinos. Cryptozoologists see dinos in African lakes but it's a sad drab world -- there are no dinos in the lake, or on the plateau mountain of Auyan Tepui, and Conan-Doyle's dream of a Lost World is just a dream. No dinos, just a 3212-foot-high waterfall, the highest in the world. No pterodactyls in Illinois, although one was spotted in 1948. No plesiosaurs in Loch Ness. 'Tho I canna be sure... No living fossils except a deep-water fish and deep-water nautilii that kept their heads down (or shells down).

> They're gone. It was quick but probably not painless. Read more (much more) at:
http://books.google.com/books?id=ZaIO8wl_OZIC
if you can stand to read a GoogleBook, or this one:
http://books.google.com/books?id=kAup0TOL09gC
particularly Graham Ryder's article starting on page 31.

>He points out that the K-T boundary was quickly recognized almost two centuries ago. It was quite different than other boundaries and it was always clear that it was a sharp and abrupt change; Darwin called it "wonderfully sudden."

> Actually finding the boundary in the field was easy, even
in 1850 -- chalk overlaid with gooey clay. Thus, it is a
particularly ironic reversal that some geologists spend a
lot of time and effort to make it seem gradual when the
one thing geologists knew about it for centuries was
that it was abrupt.

> EP, you asked me to calculate the impact. It's been done by far better than I; I'll send you a list of URL's Off-List. Size?

> Think Big. Then... Think Bigger.

> At 170 kilometers, Chicxulub is the third biggest impact crater surviving on the Earth's surface, being exceeded only by the 250km Sudbury (1.85 billion years old) with twice its area and the 300km Vredefort (2.2 billion years old) with three times its area. They're arguing about whether there's an outer ring wall at 300 kilometers
> at Chicxulub (making it as big as Vredefort, unless Vreddy had an outer ring at 550 km...)
>
> Think of the movie "Armageddon" without the happy ending. The Chicxulub Fall wasn't a once-in-a-100,000,000-year accident.

> It was a once-in-a-billion-year accident. Did it briefly set the entire planet on fire? They say so... Take a good look at:
http://www.lpi.usra.edu/science/kring/e ... fires.html

> It changed the World forever. "50% of all genera were extinct. 17% of all animal families were wiped out. 50% of all angiosperms in North America alone went extinct. All of the dinosaurs save the birds were extinct. The great marine reptiles were gone. The pterosaurs were toast. The majority of the archosaurs and most diapsid megafauna was swept away. The archosaur grip on the ecologies that had lasted for 150 million years, was ended."
http://thedragonstales.blogspot.com/200 ... -fell.html

> And see, he didn't even mention the ammonites either....

> The same Joanne Bourgeois that thinks chevrons are not
tidal-wave-deposited (recently discussed on the List) is the one who modeled the tsunami from Chicxulub as being
4000 to 5000 meters high. A tidal wave three miles high. Hmmm.

> At the Brazos coast in Texas where Keller's sediments are, it was still 100+ meters. Bourgeois describes the sediments as full of fragments and shards: fish teeth, dead wood, shell fragments, chunks of smashed clay...

http://books.google.com/books?id=o-837r ... t&resnum=5

> Doesn't sound like quiet sedimentation to me...

> Unless, like Keller, you think the biggest impact in a billion years had no effect whatsoever -- none. "Not a single species went extinct as a result of the Chicxulub impact," she says.

> Lady, I have a bridge in Brooklyn I want to sell you... at a very reasonable price. Used, yes... but in excellent condition.

> Sterling K. Webb

EP - And I have about 1 federal employee at NSF who needs to be relieved.

> From: "Mexicodoug"
> Subject: Re: [meteorite-list] The COMET that killed the dinosaurs

>Hi Ed,

> The case we are discussing is the suspected and curious Nickel and Gold rich pseudometeorite or meteorite from DSDP Hole 576 recovered by UCLA's Cosmochemist Frank T. Kyte.

> Without giving my personal opinion, here are Kyte's thought on whether his object and the Chicxulub impactor in general is a COMET:

> "Analyses of a small fossil meteorite [sic] as well as the isotopic composition of Cr in K-T boundary sediments, point to a projectile similar to CARBONACEOUS CHONDRITE. Physical debris (i.e., Ni-rich spinels) in the global fallout is restricted to a single layer, and
there is no strong evidence to support any hypothesis other than a single, geologically instantaneous accretionary event. This observation, in addition to the apparent lack of an increased flux of 3-He at the K-T boundary are strong arguments against a comet shower
at 65 Ma. That the K-T meteorite [sic] is more similar to anhydrous, porous IDPs is also reason to suspect an asteroidal, rather than a cometary source for the K-T projectile."

Ref: Catastrophic Events and Mass Extinctions, eds. Christian Koeberl, Kenneth G. MacLeod: GSA Special Paper 356 Kyte, F.T., (2002) Boulder, Co., "Traces of the extraterrestrial component in sediments and inferences for Earth's accretion history", pp. 21-38.


While I hope this straightens it out for you, min, I doubt it. Based on many years of experience. Now how much you want to pay me and sterling for straightening this out for you?

E.P. Grondine
Man and Impact in the Americas


_

[Rokcet Scientist]

What's all that got to do with the price of rice, E.P.? This thread is about boats and the hominid diaspora in an era between say 4 million years BP and 10,000 BC. Not about impacts 65 million years BP.

[E.P. Grondine]

What's all that got to do with the price of rice, E.P.? This thread is about boats and the hominid diaspora in an era between say 4 million years BP and 10,000 BC. Not about impacts 65 million years BP.

Sterling does have a pretty succinct way of summarizing things:

"People who don't like the idea of impact as a process like Keller; she plays to them. But then, those people don't study impacts. Nasty things. And they don't know much about them. Then, she turns around and suggests even bigger impacts.

"She gets a great deal of press but very few supporters. She's very popular among people with a "cultural" interest in science."

Sterling pretty well summed it up.

The topic is human dispersal and evolution; the Malay impact 1.8 million years age played a large role in that, as did the Zamanshin impact, RS.

[Digit]

I never said it wasn't!

And I never said that you did! If you check back a few posts you will find that when I have 'accused' you of something I have stated 'your words!!' Check!
The speed they moved at is considered high by experts, I make no personal claims. Any way how long was the coast line between your points at that time?
Meantime you might want to study this...

http://bruceowen.com/worldprehist/3250s04.htm

* rapid in geological terms
* but not fast at all in human terms
o just 10 miles per generation (at 20 years per generation) would get hominids from Africa to Indonesia in only 20,000 years (0.02 my), fast enough to look instantaneous by current dating methods


...somewhat different to your timscale!!

Roy.

[Rokcet Scientist]

I never said it wasn't!

And I never said that you did!.

Yes you did! 5 posts back, Roy: with "So now you accept that warfare is one of the options" (underline mine) you implied that at one time I said it was not.

just 10 miles per generation (at 20 years per generation) would get hominids from Africa to Indonesia in only 20,000 years (0.02 my)

But it took them a full million years. Fifty times longer! So if "only" 20,000 years is fast, a million years is terribly slow!

[Digit]

Yes you did! 5 posts back, Roy: with "So now you accept that warfare is one of the options" (underline mine) you implied that at one time I said it was not.

Interpret my language how the hell you like, but I at least know what I mean!
And probably somewhat better than you.
Now you tell why your expert opinion is better than the 'expert' I have quoted.
You have seen my evidence for the time scale, where's yours?

Roy.

[Rokcet Scientist]

You have seen my evidence for the time scale, where's yours?

In the post above yours, Roy, using your evidence as yardstick. But I'll repeat for good measure:

just 10 miles per generation (at 20 years per generation) would get hominids from Africa to Indonesia in only 20,000 years (0.02 my)

But it took them a full million years. Fifty times longer! So if "only" 20,000 years is fast, a million years is terribly slow!

I'll go walk the dog now.

[E.P. Grondine]

the speed at which they spread suggests that they did avoid conflict

How so, Roy? From 1,8 million years BP (Dmanisi) to 800,000 years BP (Java and Beijing) is a full million years. Do you consider that a 'speedy' diaspora? I don't.

Kind of ignoring the new Malaysia findings there, RS. 1.8 MYA.

On the topic of warfare, humans are the only animal in which a large (~%5) number of the females die in childbirth. I seem to remember that this is an effect of walking upright. If so, then from the point of DNA human warfare made sense - get more females, or get less able males killed. Whatever the analysis, as we now live in the era of WMD, we better figure the source of warfare out quick.

[I've got a splitting headache. I can remember this stuff but can't remember where I put my hat; I've been typing all of this using one finger on my left hand. Welcome to the wonderful world of stroke.]

[Rokcet Scientist]

Kind of ignoring the new Malaysia findings there, RS. 1.8 MYA.

There are? That's interesting. Can you dig up a link for me?
Would obviously have me to reconsider my scenario. That's fine. Maybe it even fits in. There are still a lot of holes that need to be filled in. But it would increase the likelyhood of early HE walking to the Andamans.

But I'm glad that the Chinese HE finds along their coasts and later HE inland pretty much nail down my coastline/detour script.

[Minimalist]

It has been, Min, you just don't know it yet. Here is the quick backgrounder:

E.P.....do you understand that those long, disjointed posts of yours are virtually unreadable?

I get it. Your life is wrapped up in proving the importance of asteroid hits. You react negatively to any suggestion that they are not as frequent or devastating as you think they are.

Meanwhile, R/S is right. This thread is about supposed to be about Boats and the spread of HE/HSS around the world.

[Minimalist]

So if "only" 20,000 years is fast, a million years is terribly slow!

Of course, they were not aware that there was any sort of race going on. Time cards had not been invented!

[Sam Salmon]

Recent events have put me to mind of the fragility of these tiny groups.

Devastating earthquakes like the one in Sumatra, a massive Tsunami like the one that hit Samoa and Northern Tonga, not to mention garden variety floods and forest fires must have knocked early humans to their knees constantly-I suppose it something of a miracle anyone survived at all.

[Digit]

But it would increase the likelyhood of early HE walking to the Andamans.

How?

Roy.

[Minimalist]

Recent events have put me to mind of the fragility of these tiny groups.

Devastating earthquakes like the one in Sumatra, a massive Tsunami like the one that hit Samoa and Northern Tonga, not to mention garden variety floods and forest fires must have knocked early humans to their knees constantly-I suppose it something of a miracle anyone survived at all.

Not to mention Toba which is supposed to have pushed HSS to the brink of extinction.