[meteorite-list] Mammoth Stew

From: mexicodoug <mexicodoug_at_meteoritecentral.com>
Date: Mon, 17 Dec 2007 03:03:40 -0600
Message-ID: <001f01c8408b$b8b21710$4001a8c0_at_MICASA>

Jason and Sterling chatted::

"But we have to account for a crater (well, impactor at least - or maybe
just call it a 'body') large enough to deposit such a layer of dust, and I
don't think that you're going to get that from such a small impact."

Dear Listees,
Tusk, tsk ... Sounds like it would be "Mammoth" impact to me ...

The mammoths may be 34,000 years old, but who's to say the meteorites (if,
indeed this is genuinely meteoritical which is still the $64,000 question)
are in the tusks that long? Are the tusks fossilized? Maybe some
Cro-Magnonish Clovis peoples found the tusks sticking out of the receding
ice 10,000 -11,500 years ago, were understandably impressed, and pinned them
decoratively to trees and walls (using iron meteorite thumb tacks they
learned to make, after meteorite firestarters were used for their cookouts?
[Like the Cape York story]) Meteorite mysteries, are frequently related to
the "human" factor ...

Best wishes, Life,
Doug
I think I'll pass on the hairy mammoth stew, peppered or not, unless I'm
stuck on a glacier.

----- Original Message -----
From: "Jason Utas" <meteoritekid at gmail.com>
To: "Meteorite-list" <meteorite-list at meteoritecentral.com>
Sent: Monday, December 17, 2007 12:58 AM
Subject: Re: [meteorite-list] Mammoth Stew


> Sterling, E.P., All,
>
>> For the record, I like my peppered mammoth
>> with lemon butter...
>
> Thick-cut, salt and pepper.
>
>> Jason, think about Tunguska. A 25 megaton airburst
>> that left no crater, no pits, not even the tiniest, no
>> material remains whatsoever, no isotopic traces in
>> reliable amounts, nothing with a side order of zilch.
>> (Ok, possible microscopic spherules in trees, not
>> 2-3 mm particles, and disputed to boot).
>
> Exactly; nothing was left; no evidence, no anything.
> How, so, can you relate this to Tunguska, when the evidence that we
> have for it is completely different?
>
>> Yet, had it occurred over Belgium, it would have
>> killed 90% of the population of the nation, or if over
>> metropolitan London simply removed the world's
>> then-largest city from the map. IF we did not have
>> the Russian newspapers, the native reports, Kulik's
>> photos of the trees (gone now), could anyone today
>> detect that it had ever occurred? And it hasn't even
>> been a lousy century! (The Centennial is next June!)
>
> But you're lacking the isotopic evidence, etc. Not so with this layer
> of...whatever it is.
>
>> Like a belief in the existence of the atom or any other
>> thing that we cannot and never will see with our own
>> eyes, vast numbers of craters have covered on Earth.
>
> Mhm...
>
>> 1) The flux of impactors at the Earth is identical to the
>> flux of impactors at the Moon, since the two bodies
>> occupy the same orbit and always have, the Moon like
>> a celestial tick on our neck.
>
> Well they haven't always, but, irrelevant to this discussion.
>
>> 2) The pristine state of the Moon allows for a very
>> accurate count of the number of impactors that have
>> struck the Moon (allowing for extrapolation for the
>> areas covered by flood basalts -- ~170,000 impactors
>> producing craters of one kilometer or more).
>
> Fine, fine, information we all know.
>
>> 3) It's mathematical child's play to scale up the lunar
>> impactor flux to the Earth's size and add in the increase
>> in "gravitational" cross section caused by the Earth's
>> stronger gravity (13.5 + 4.4 = ~18 times more impactors).
>> Not only that, but the stronger terrestrial gravity means
>> that ANY impactor will make a bigger crater on the Earth
>> than it would have if it had smacked the Moon instead.
>> (And for impactors that would make a crater 1 km or
>> more in diameter, the atmosphere is not a factor.)
>
> Well, we also have to take into account that a fist-sized meteorite
> will make a crater six or so meters across on the moon whereas on
> earth such a thing would make nothing more than a pretty light show.
>
>> 4) So we can easily determine the number of craters on
>> the Earth. No problem. The Earth has had approximately
>> three million (3,000,000) impactors, so we must have
>> three million (3,000,000) craters over one kilometer in
>> diameter!
>
> Subtract the smaller craters and account for erosion...we're talking
> about the past fifty thousand years, not 2+ billion. The number of
> impactors over this timeframe was smaller than that of before, and
> erosion has taken a lesser tole on such craters, as they're younger.
>
>> Before we all run outdoors to check out the vista of
>> craters, craters, craters everywhere -- sorry, they're gone.
>> After counting craters from the obvious to those hidden
>> to the eyes of all but gravitometers, 17,999 craters out of
>> every 18,000 craters have vanished utterly from the planet
>> without a trace!
>
> See above...this makes sense given that most of the craters were
> formed before the timeframe that is of any importance to this
> discussion.
>
>> So, both these statements are true, in their fashion:
>> a) The Earth is the most cratered body in the solar system.
>> b) The Earth is the least cratered body in the solar system.*
>> (* except for the other really interesting place... Titan)
>
> Well, maybe, maybe not...Mars should probably be more so.
>
>> >From 98,000 years BP to 14,000 BP, a northern polar
>> ice cap was in place, yes, with retreats and advances,
>> recensions and excursions, in this area or that area, or
>> all areas, changes whose precise timing is hard to pin
>> down, but for ALL of that 84,000 years, there was a
>> land based ice cap in most of the northern hemisphere,
>> varying in thickness from 1000 meters to 3000 meters.
>
> Right-o.
>
>> Two miles of vertical ice. Now gone. What traces
>> of a crater in its upper surface do you expect would
>> survive? Just for fun, I went and modeled on the LPI
>> Impact Calculator a Ten Kilometer Comet a little less
>> dense than water making a 30-degree impact, releasing
>> 8 million MegaTons TNT [or 8 TeraTons] energy
>> equivalent, and its crater wouldn't have reached through
>> an ice cap that thick; the crater was only 1100 meters
>> deep. Also, I don't know if anyone has seriously
>> analyzed a cratering event in deep ice! Ice, hard as
>> it seems, has properties midway between weak rock
>> and deep water (which produces much shallower
>> craters than rock).
>
> But we have to account for a crater (well, impactor at least - or
> maybe just call it a 'body') large enough to deposit such a layer of
> dust, and I don't think that you're going to get that from such a
> small impact.
>
>> Call the Earth the Eraser Planet. The Ice has to be one
>> of the best of the many erasers available. Three million
>> craters and only 170 of them still show... It's almost like
>> "they" were trying to trick us into an unreasonable
>> complacency, isn't it?
>
> See above...your numbers are off due to a prejudice towards older
> craters that were undoubtedly more common - and have suffered a great
> deal more due to the effects of weathering.
>
>> We've had a lot of questions about the difference
>> between an asteroid impact and a comet impact.
>> The difference between an asteroid impact and
>> a comet impact of similar energy? The outcome
>> of each is different, though the crater's the same size:
>> http://www.news.uiuc.edu/scitips/02/1025craters.html
>
> Right, and what it comes down to is size.
>
>> Surprised to find this, as I've never heard it mentioned
>> before: a 10-yr-old study, the last by Gene Shoemaker,
>> that demonstrated a He3 extraterrestrial dust layer at
>> 36 million years ago that persisted for over two million
>> years and overlaps the times of the Popagai and the
>> Chesapeake Bay craters. He considered it the evidence of
>> a period of "comet showers." But other events are also
>> possible explanations.
>> http://mr.caltech.edu/media/lead/052198KF.html
>
> How big are those craters again? If I recall, at least the Chesapeake
> crater is fairly sizable...
>
>> One of the disadvantages of being a short-lived creature
>> with a recording civilization only a few thousand years old
>> in a universe 15 billion years old is the problem of detecting
>> threats that do NOT leave long persisting warnings behind.
>> Instead of 3,000,000 craters, there were a few, so we were
>> able to deduce the rest, but only in the last (less than) 50
>> years.
>
> Prejudiced number...
>
>> We should not assume that we have now identified all
>> possible threats from the universe at large. A threat event
>> with few trace markers could be quite frequent and still be
>> very difficult to detect in the absence of such an event.
>
> Well, mass extinctions should give us something of a clue even if we
> can't find traces of an impact, but if I'm not mistaken, the mass
> die-outs occurred several thousand years after the dust layer was laid
> down, no?
>
> Regards,
> Jason
>
>>
>> Sterling K. Webb
>> ----------------------------------------------------------------------
>>
>> ----- Original Message -----
>> From: "E.P. Grondine" <epgrondine at yahoo.com>
>> To: <meteorite-list at meteoritecentral.com>
>> Sent: Sunday, December 16, 2007 8:05 PM
>> Subject: Re: [meteorite-list] Mammoth Stew
>>
>>
>> Hi all -
>>
>> 1) From the descriptions, the spherules in the tusks
>> appear to be the result of the condensation of iron
>> plasma, the same as at Barringer crater.
>>
>> 2) When Nininger did his survey of spherules at
>> Barringer crater, I doubt if he looked several hundred
>> miles away from the crater - that's what I think of as
>> a ballistic re-entry. The internet site for this
>> impact has been greatly improved, and I'm sure that
>> some here must have been active in that.
>>
>> I don't know about winds at the time of Barringer
>> impact, but I can't remember any statement as to angle
>> of impact. But then I can't remember many things
>> anymore.
>>
>> 3) I have no idea what the spherules' temperatures
>> were when they landed - but my guess is that they must
>> have been too high to use any type of barrel to
>> duplicate their hitting the bones. My guess is that
>> magnetic suspension and acceleration would be about
>> it.
>>
>> 4) As far as locating the 31,000 BCE crater goes, its
>> possible that the situation might be similar to the
>> K-T crater - that one took 10 years to find. Same
>> goes for impact point(s) for the 10,900 BCE event. If
>> you look at impact crater distribution maps, you'll
>> see that more have been found in the areas where
>> geologists live.
>>
>> good hunting,
>> E.P. Grondine
>> Man and Impact in the Americas
>>
>>
>>
>>
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Received on Mon 17 Dec 2007 04:03:40 AM PST